151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski/* 22c87ad3a45cecf9e344487cad1abfdebe79f2c7cNarayan Kamath * Copyright (C) 2014 The Android Open Source Project 351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved. 451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This code is free software; you can redistribute it and/or modify it 751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * under the terms of the GNU General Public License version 2 only, as 851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * published by the Free Software Foundation. Oracle designates this 951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * particular file as subject to the "Classpath" exception as provided 1051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * by Oracle in the LICENSE file that accompanied this code. 1151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 1251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This code is distributed in the hope that it will be useful, but WITHOUT 1351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * version 2 for more details (a copy is included in the LICENSE file that 1651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * accompanied this code). 1751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 1851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * You should have received a copy of the GNU General Public License version 1951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 2 along with this work; if not, write to the Free Software Foundation, 2051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 2251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * or visit www.oracle.com if you need additional information or have any 2451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * questions. 2551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 2651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 2751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskipackage java.lang; 28fa5b565a3f6c6d7cbd6106ee8d360304c3a939a3Igor Murashkinimport dalvik.annotation.optimization.FastNative; 2951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskiimport java.io.*; 3051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskiimport java.util.*; 3151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 3251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski/** 3351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The {@code Throwable} class is the superclass of all errors and 3451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exceptions in the Java language. Only objects that are instances of this 3551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * class (or one of its subclasses) are thrown by the Java Virtual Machine or 3651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * can be thrown by the Java {@code throw} statement. Similarly, only 3751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * this class or one of its subclasses can be the argument type in a 3851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code catch} clause. 3951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 4051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * For the purposes of compile-time checking of exceptions, {@code 4151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Throwable} and any subclass of {@code Throwable} that is not also a 4251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * subclass of either {@link RuntimeException} or {@link Error} are 4351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * regarded as checked exceptions. 4451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 4551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>Instances of two subclasses, {@link java.lang.Error} and 4651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link java.lang.Exception}, are conventionally used to indicate 4751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * that exceptional situations have occurred. Typically, these instances 4851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * are freshly created in the context of the exceptional situation so 4951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * as to include relevant information (such as stack trace data). 5051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 5151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>A throwable contains a snapshot of the execution stack of its 5251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * thread at the time it was created. It can also contain a message 5351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * string that gives more information about the error. Over time, a 5451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable can {@linkplain Throwable#addSuppressed suppress} other 5551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwables from being propagated. Finally, the throwable can also 5651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * contain a <i>cause</i>: another throwable that caused this 5751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable to be constructed. The recording of this causal information 5851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * is referred to as the <i>chained exception</i> facility, as the 5951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause can, itself, have a cause, and so on, leading to a "chain" of 6051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exceptions, each caused by another. 6151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 6251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>One reason that a throwable may have a cause is that the class that 6351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throws it is built atop a lower layered abstraction, and an operation on 6451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the upper layer fails due to a failure in the lower layer. It would be bad 6551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * design to let the throwable thrown by the lower layer propagate outward, as 6651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * it is generally unrelated to the abstraction provided by the upper layer. 6751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Further, doing so would tie the API of the upper layer to the details of 6851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * its implementation, assuming the lower layer's exception was a checked 6951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exception. Throwing a "wrapped exception" (i.e., an exception containing a 7051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause) allows the upper layer to communicate the details of the failure to 7151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * its caller without incurring either of these shortcomings. It preserves 7251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the flexibility to change the implementation of the upper layer without 7351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * changing its API (in particular, the set of exceptions thrown by its 7451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * methods). 7551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 7651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>A second reason that a throwable may have a cause is that the method 7751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * that throws it must conform to a general-purpose interface that does not 7851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * permit the method to throw the cause directly. For example, suppose 7951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * a persistent collection conforms to the {@link java.util.Collection 8051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Collection} interface, and that its persistence is implemented atop 8151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code java.io}. Suppose the internals of the {@code add} method 8251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * can throw an {@link java.io.IOException IOException}. The implementation 8351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * can communicate the details of the {@code IOException} to its caller 8451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * while conforming to the {@code Collection} interface by wrapping the 8551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code IOException} in an appropriate unchecked exception. (The 8651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * specification for the persistent collection should indicate that it is 8751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * capable of throwing such exceptions.) 8851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 8951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>A cause can be associated with a throwable in two ways: via a 9051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * constructor that takes the cause as an argument, or via the 9151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #initCause(Throwable)} method. New throwable classes that 9251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * wish to allow causes to be associated with them should provide constructors 9351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * that take a cause and delegate (perhaps indirectly) to one of the 9451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code Throwable} constructors that takes a cause. 9551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 9651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Because the {@code initCause} method is public, it allows a cause to be 9751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * associated with any throwable, even a "legacy throwable" whose 9851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * implementation predates the addition of the exception chaining mechanism to 9951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code Throwable}. 10051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 10151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>By convention, class {@code Throwable} and its subclasses have two 10251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * constructors, one that takes no arguments and one that takes a 10351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code String} argument that can be used to produce a detail message. 10451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Further, those subclasses that might likely have a cause associated with 10551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * them should have two more constructors, one that takes a 10651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code Throwable} (the cause), and one that takes a 10751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code String} (the detail message) and a {@code Throwable} (the 10851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause). 10951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 11051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @author unascribed 11151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @author Josh Bloch (Added exception chaining and programmatic access to 11251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack trace in 1.4.) 11351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @jls 11.2 Compile-Time Checking of Exceptions 11451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since JDK1.0 11551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 11651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskipublic class Throwable implements Serializable { 11751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** use serialVersionUID from JDK 1.0.2 for interoperability */ 11851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static final long serialVersionUID = -3042686055658047285L; 11951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 12051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 12151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Native code saves some indication of the stack backtrace in this slot. 12251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 123de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski private transient volatile Object backtrace; 12451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 12551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 12651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Specific details about the Throwable. For example, for 12751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code FileNotFoundException}, this contains the name of 12851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the file that could not be found. 12951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 13051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @serial 13151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 13251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private String detailMessage; 13351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 13451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 13551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 13651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Holder class to defer initializing sentinel objects only used 13751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * for serialization. 13851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 13951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static class SentinelHolder { 14051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 14151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@linkplain #setStackTrace(StackTraceElement[]) Setting the 14251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack trace} to a one-element array containing this sentinel 14351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * value indicates future attempts to set the stack trace will be 14451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ignored. The sentinal is equal to the result of calling:<br> 14551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code new StackTraceElement("", "", null, Integer.MIN_VALUE)} 14651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 14751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public static final StackTraceElement STACK_TRACE_ELEMENT_SENTINEL = 14851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski new StackTraceElement("", "", null, Integer.MIN_VALUE); 14951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 15051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 15151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Sentinel value used in the serial form to indicate an immutable 15251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack trace. 15351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 15451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public static final StackTraceElement[] STACK_TRACE_SENTINEL = 15551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski new StackTraceElement[] {STACK_TRACE_ELEMENT_SENTINEL}; 15651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 15751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 15851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /* 15951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * To allow Throwable objects to be made immutable and safely 16051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * reused by the JVM, such as OutOfMemoryErrors, fields of 16151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Throwable that are writable in response to user actions, cause, 16251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stackTrace, and suppressedExceptions obey the following 16351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * protocol: 16451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 16551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 1) The fields are initialized to a non-null sentinel value 16651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * which indicates the value has logically not been set. 16751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 16851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 2) Writing a null to the field indicates further writes 16951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * are forbidden 17051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 17151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 3) The sentinel value may be replaced with another non-null 17251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * value. 17351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 17451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * For example, implementations of the HotSpot JVM have 17551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * preallocated OutOfMemoryError objects to provide for better 17651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * diagnosability of that situation. These objects are created 17751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * without calling the constructor for that class and the fields 17851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * in question are initialized to null. To support this 17951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * capability, any new fields added to Throwable that require 18051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * being initialized to a non-null value require a coordinated JVM 18151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * change. 18251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 18351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 18451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 18551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The throwable that caused this throwable to get thrown, or null if this 18651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable was not caused by another throwable, or if the causative 18751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable is unknown. If this field is equal to this throwable itself, 18851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * it indicates that the cause of this throwable has not yet been 18951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * initialized. 19051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 19151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @serial 19251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 19351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 19451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private Throwable cause = this; 19551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 19651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 19751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The stack trace, as returned by {@link #getStackTrace()}. 19851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 19951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The field is initialized to a zero-length array. A {@code 20051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * null} value of this field indicates subsequent calls to {@link 20151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #setStackTrace(StackTraceElement[])} and {@link 20251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #fillInStackTrace()} will be be no-ops. 20351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 20451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @serial 20551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 20651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 2076975f84c2ed72e1e26d20190b6f318718c849008Tobias Thierer // Android-changed. 20862431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath private StackTraceElement[] stackTrace = libcore.util.EmptyArray.STACK_TRACE_ELEMENT; 20951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 21051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 21151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The list of suppressed exceptions, as returned by {@link 21251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #getSuppressed()}. The list is initialized to a zero-element 21351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * unmodifiable sentinel list. When a serialized Throwable is 21451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * read in, if the {@code suppressedExceptions} field points to a 21551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * zero-element list, the field is reset to the sentinel value. 21651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 21751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @serial 21851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.7 21951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 220de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski private List<Throwable> suppressedExceptions = Collections.emptyList(); 22151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 22251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** Message for trying to suppress a null exception. */ 22351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static final String NULL_CAUSE_MESSAGE = "Cannot suppress a null exception."; 22451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 22551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** Message for trying to suppress oneself. */ 22651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static final String SELF_SUPPRESSION_MESSAGE = "Self-suppression not permitted"; 22751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 22851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** Caption for labeling causative exception stack traces */ 22951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static final String CAUSE_CAPTION = "Caused by: "; 23051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 23151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** Caption for labeling suppressed exception stack traces */ 23251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static final String SUPPRESSED_CAPTION = "Suppressed: "; 23351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 23451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 23551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Constructs a new throwable with {@code null} as its detail message. 23651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The cause is not initialized, and may subsequently be initialized by a 23751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * call to {@link #initCause}. 23851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 23951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>The {@link #fillInStackTrace()} method is called to initialize 24051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the stack trace data in the newly created throwable. 24151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 24251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public Throwable() { 24351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski fillInStackTrace(); 24451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 24551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 24651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 24751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Constructs a new throwable with the specified detail message. The 24851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause is not initialized, and may subsequently be initialized by 24951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * a call to {@link #initCause}. 25051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 25151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>The {@link #fillInStackTrace()} method is called to initialize 25251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the stack trace data in the newly created throwable. 25351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 25451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param message the detail message. The detail message is saved for 25551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * later retrieval by the {@link #getMessage()} method. 25651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 25751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public Throwable(String message) { 25851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski fillInStackTrace(); 25951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski detailMessage = message; 26051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 26151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 26251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 26351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Constructs a new throwable with the specified detail message and 26451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause. <p>Note that the detail message associated with 26551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code cause} is <i>not</i> automatically incorporated in 26651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * this throwable's detail message. 26751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 26851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>The {@link #fillInStackTrace()} method is called to initialize 26951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the stack trace data in the newly created throwable. 27051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 27151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param message the detail message (which is saved for later retrieval 27251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * by the {@link #getMessage()} method). 27351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param cause the cause (which is saved for later retrieval by the 27451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #getCause()} method). (A {@code null} value is 27551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * permitted, and indicates that the cause is nonexistent or 27651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * unknown.) 27751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 27851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 27951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public Throwable(String message, Throwable cause) { 28051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski fillInStackTrace(); 28151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski detailMessage = message; 28251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.cause = cause; 28351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 28451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 28551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 28651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Constructs a new throwable with the specified cause and a detail 28751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * message of {@code (cause==null ? null : cause.toString())} (which 28851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * typically contains the class and detail message of {@code cause}). 28951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This constructor is useful for throwables that are little more than 29051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * wrappers for other throwables (for example, {@link 29151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * java.security.PrivilegedActionException}). 29251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 29351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>The {@link #fillInStackTrace()} method is called to initialize 29451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the stack trace data in the newly created throwable. 29551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 29651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param cause the cause (which is saved for later retrieval by the 29751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #getCause()} method). (A {@code null} value is 29851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * permitted, and indicates that the cause is nonexistent or 29951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * unknown.) 30051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 30151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 30251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public Throwable(Throwable cause) { 30351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski fillInStackTrace(); 30451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski detailMessage = (cause==null ? null : cause.toString()); 30551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.cause = cause; 30651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 30751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 30851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 30951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Constructs a new throwable with the specified detail message, 31051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause, {@linkplain #addSuppressed suppression} enabled or 31151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * disabled, and writable stack trace enabled or disabled. If 31251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppression is disabled, {@link #getSuppressed} for this object 31351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * will return a zero-length array and calls to {@link 31451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #addSuppressed} that would otherwise append an exception to the 31551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed list will have no effect. If the writable stack 31651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * trace is false, this constructor will not call {@link 31751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #fillInStackTrace()}, a {@code null} will be written to the 31851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code stackTrace} field, and subsequent calls to {@code 31951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * fillInStackTrace} and {@link 32051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #setStackTrace(StackTraceElement[])} will not set the stack 32151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * trace. If the writable stack trace is false, {@link 32251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #getStackTrace} will return a zero length array. 32351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 32451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>Note that the other constructors of {@code Throwable} treat 32551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppression as being enabled and the stack trace as being 32651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * writable. Subclasses of {@code Throwable} should document any 32751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * conditions under which suppression is disabled and document 32851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * conditions under which the stack trace is not writable. 32951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Disabling of suppression should only occur in exceptional 33051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * circumstances where special requirements exist, such as a 33151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * virtual machine reusing exception objects under low-memory 33251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * situations. Circumstances where a given exception object is 33351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * repeatedly caught and rethrown, such as to implement control 33451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * flow between two sub-systems, is another situation where 33551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * immutable throwable objects would be appropriate. 33651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 33751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param message the detail message. 33851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param cause the cause. (A {@code null} value is permitted, 33951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * and indicates that the cause is nonexistent or unknown.) 34051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param enableSuppression whether or not suppression is enabled or disabled 34151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param writableStackTrace whether or not the stack trace should be 34251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * writable 34351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 34451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @see OutOfMemoryError 34551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @see NullPointerException 34651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @see ArithmeticException 34751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.7 34851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 34951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski protected Throwable(String message, Throwable cause, 35051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski boolean enableSuppression, 35151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski boolean writableStackTrace) { 35251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (writableStackTrace) { 35351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski fillInStackTrace(); 35451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } else { 35551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski stackTrace = null; 35651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 35751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski detailMessage = message; 35851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.cause = cause; 35951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (!enableSuppression) 36051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski suppressedExceptions = null; 36151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 36251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 36351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 36451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Returns the detail message string of this throwable. 36551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 36651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return the detail message string of this {@code Throwable} instance 36751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * (which may be {@code null}). 36851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 36951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public String getMessage() { 37051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return detailMessage; 37151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 37251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 37351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 37451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Creates a localized description of this throwable. 37551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Subclasses may override this method in order to produce a 37651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * locale-specific message. For subclasses that do not override this 37751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * method, the default implementation returns the same result as 37851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code getMessage()}. 37951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 38051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return The localized description of this throwable. 38151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since JDK1.1 38251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 38351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public String getLocalizedMessage() { 38451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return getMessage(); 38551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 38651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 38751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 38851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Returns the cause of this throwable or {@code null} if the 38951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause is nonexistent or unknown. (The cause is the throwable that 39051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * caused this throwable to get thrown.) 39151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 39251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>This implementation returns the cause that was supplied via one of 39351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the constructors requiring a {@code Throwable}, or that was set after 39451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * creation with the {@link #initCause(Throwable)} method. While it is 39551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * typically unnecessary to override this method, a subclass can override 39651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * it to return a cause set by some other means. This is appropriate for 39751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * a "legacy chained throwable" that predates the addition of chained 39851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exceptions to {@code Throwable}. Note that it is <i>not</i> 39951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * necessary to override any of the {@code PrintStackTrace} methods, 40051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * all of which invoke the {@code getCause} method to determine the 40151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause of a throwable. 40251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 40351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return the cause of this throwable or {@code null} if the 40451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause is nonexistent or unknown. 40551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 40651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 40751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public synchronized Throwable getCause() { 40851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return (cause==this ? null : cause); 40951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 41051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 41151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 41251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Initializes the <i>cause</i> of this throwable to the specified value. 41351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * (The cause is the throwable that caused this throwable to get thrown.) 41451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 41551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>This method can be called at most once. It is generally called from 41651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * within the constructor, or immediately after creating the 41751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable. If this throwable was created 41851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * with {@link #Throwable(Throwable)} or 41951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #Throwable(String,Throwable)}, this method cannot be called 42051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * even once. 42151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 42251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>An example of using this method on a legacy throwable type 42351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * without other support for setting the cause is: 42451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 42551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 42651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * try { 42751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * lowLevelOp(); 42851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } catch (LowLevelException le) { 42951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throw (HighLevelException) 43051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * new HighLevelException().initCause(le); // Legacy constructor 43151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 43251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 43351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 43451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param cause the cause (which is saved for later retrieval by the 43551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #getCause()} method). (A {@code null} value is 43651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * permitted, and indicates that the cause is nonexistent or 43751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * unknown.) 43851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return a reference to this {@code Throwable} instance. 43951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @throws IllegalArgumentException if {@code cause} is this 44051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable. (A throwable cannot be its own cause.) 44151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @throws IllegalStateException if this throwable was 44251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * created with {@link #Throwable(Throwable)} or 44351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #Throwable(String,Throwable)}, or this method has already 44451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * been called on this throwable. 44551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 44651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 44751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public synchronized Throwable initCause(Throwable cause) { 44851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (this.cause != this) 44951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new IllegalStateException("Can't overwrite cause with " + 45051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Objects.toString(cause, "a null"), this); 45151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (cause == this) 45251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new IllegalArgumentException("Self-causation not permitted", this); 45351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.cause = cause; 45451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return this; 45551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 45651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 45751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 45851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Returns a short description of this throwable. 45951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The result is the concatenation of: 46051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <ul> 46151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <li> the {@linkplain Class#getName() name} of the class of this object 46251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <li> ": " (a colon and a space) 46351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <li> the result of invoking this object's {@link #getLocalizedMessage} 46451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * method 46551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </ul> 46651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * If {@code getLocalizedMessage} returns {@code null}, then just 46751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the class name is returned. 46851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 46951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return a string representation of this throwable. 47051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 47151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public String toString() { 47251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski String s = getClass().getName(); 47351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski String message = getLocalizedMessage(); 47451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return (message != null) ? (s + ": " + message) : s; 47551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 47651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 47751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 47851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Prints this throwable and its backtrace to the 47951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * standard error stream. This method prints a stack trace for this 48051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code Throwable} object on the error output stream that is 48151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the value of the field {@code System.err}. The first line of 48251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * output contains the result of the {@link #toString()} method for 48351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * this object. Remaining lines represent data previously recorded by 48451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the method {@link #fillInStackTrace()}. The format of this 48551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * information depends on the implementation, but the following 48651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * example may be regarded as typical: 48751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <blockquote><pre> 48851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * java.lang.NullPointerException 48951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at MyClass.mash(MyClass.java:9) 49051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at MyClass.crunch(MyClass.java:6) 49151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at MyClass.main(MyClass.java:3) 49251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre></blockquote> 49351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This example was produced by running the program: 49451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 49551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * class MyClass { 49651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * public static void main(String[] args) { 49751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * crunch(null); 49851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 49951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void crunch(int[] a) { 50051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * mash(a); 50151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 50251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void mash(int[] b) { 50351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * System.out.println(b[0]); 50451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 50551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 50651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 50751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The backtrace for a throwable with an initialized, non-null cause 50851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * should generally include the backtrace for the cause. The format 50951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * of this information depends on the implementation, but the following 51051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * example may be regarded as typical: 51151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 51251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * HighLevelException: MidLevelException: LowLevelException 51351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.a(Junk.java:13) 51451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.main(Junk.java:4) 51551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Caused by: MidLevelException: LowLevelException 51651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.c(Junk.java:23) 51751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.b(Junk.java:17) 51851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.a(Junk.java:11) 51951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ... 1 more 52051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Caused by: LowLevelException 52151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.e(Junk.java:30) 52251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.d(Junk.java:27) 52351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Junk.c(Junk.java:21) 52451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ... 3 more 52551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 52651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Note the presence of lines containing the characters {@code "..."}. 52751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * These lines indicate that the remainder of the stack trace for this 52851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exception matches the indicated number of frames from the bottom of the 52951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack trace of the exception that was caused by this exception (the 53051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * "enclosing" exception). This shorthand can greatly reduce the length 53151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * of the output in the common case where a wrapped exception is thrown 53251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * from same method as the "causative exception" is caught. The above 53351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * example was produced by running the program: 53451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 53551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * public class Junk { 53651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * public static void main(String args[]) { 53751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * try { 53851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * a(); 53951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } catch(HighLevelException e) { 54051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * e.printStackTrace(); 54151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 54251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 54351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void a() throws HighLevelException { 54451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * try { 54551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * b(); 54651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } catch(MidLevelException e) { 54751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throw new HighLevelException(e); 54851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 54951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 55051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void b() throws MidLevelException { 55151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * c(); 55251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 55351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void c() throws MidLevelException { 55451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * try { 55551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * d(); 55651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } catch(LowLevelException e) { 55751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throw new MidLevelException(e); 55851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 55951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 56051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void d() throws LowLevelException { 56151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * e(); 56251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 56351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * static void e() throws LowLevelException { 56451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throw new LowLevelException(); 56551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 56651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 56751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 56851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * class HighLevelException extends Exception { 56951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * HighLevelException(Throwable cause) { super(cause); } 57051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 57151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 57251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * class MidLevelException extends Exception { 57351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * MidLevelException(Throwable cause) { super(cause); } 57451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 57551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 57651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * class LowLevelException extends Exception { 57751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * } 57851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 57951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * As of release 7, the platform supports the notion of 58051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <i>suppressed exceptions</i> (in conjunction with the {@code 58151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * try}-with-resources statement). Any exceptions that were 58251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed in order to deliver an exception are printed out 58351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * beneath the stack trace. The format of this information 58451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * depends on the implementation, but the following example may be 58551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * regarded as typical: 58651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 58751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 58851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Exception in thread "main" java.lang.Exception: Something happened 58951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo.bar(Foo.java:10) 59051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo.main(Foo.java:5) 59151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Suppressed: Resource$CloseFailException: Resource ID = 0 59251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Resource.close(Resource.java:26) 59351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo.bar(Foo.java:9) 59451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ... 1 more 59551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 59651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Note that the "... n more" notation is used on suppressed exceptions 59751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * just at it is used on causes. Unlike causes, suppressed exceptions are 59851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * indented beyond their "containing exceptions." 59951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 60051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>An exception can have both a cause and one or more suppressed 60151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exceptions: 60251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 60351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Exception in thread "main" java.lang.Exception: Main block 60451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo3.main(Foo3.java:7) 60551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Suppressed: Resource$CloseFailException: Resource ID = 2 60651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Resource.close(Resource.java:26) 60751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo3.main(Foo3.java:5) 60851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Suppressed: Resource$CloseFailException: Resource ID = 1 60951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Resource.close(Resource.java:26) 61051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo3.main(Foo3.java:5) 61151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Caused by: java.lang.Exception: I did it 61251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo3.main(Foo3.java:8) 61351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 61451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Likewise, a suppressed exception can have a cause: 61551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <pre> 61651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Exception in thread "main" java.lang.Exception: Main block 61751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo4.main(Foo4.java:6) 61851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Suppressed: Resource2$CloseFailException: Resource ID = 1 61951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Resource2.close(Resource2.java:20) 62051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * at Foo4.main(Foo4.java:5) 62151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Caused by: java.lang.Exception: Rats, you caught me 622e73fb5ccf8258577107e5b34e8a7b0ecba9e9343Tobias Thierer * at Resource2$CloseFailException.<init>(Resource2.java:45) 62351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ... 2 more 62451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * </pre> 62551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 62651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public void printStackTrace() { 62751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski printStackTrace(System.err); 62851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 62951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 63051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 63151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Prints this throwable and its backtrace to the specified print stream. 63251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 63351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param s {@code PrintStream} to use for output 63451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 63551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public void printStackTrace(PrintStream s) { 63651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski printStackTrace(new WrappedPrintStream(s)); 63751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 63851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 63951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private void printStackTrace(PrintStreamOrWriter s) { 64051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Guard against malicious overrides of Throwable.equals by 64151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // using a Set with identity equality semantics. 64251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Set<Throwable> dejaVu = 64351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Collections.newSetFromMap(new IdentityHashMap<Throwable, Boolean>()); 64451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski dejaVu.add(this); 64551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 64651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski synchronized (s.lock()) { 64751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Print our stack trace 64851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.println(this); 64951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski StackTraceElement[] trace = getOurStackTrace(); 65051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for (StackTraceElement traceElement : trace) 65151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.println("\tat " + traceElement); 65251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 65351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Print suppressed exceptions, if any 65451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for (Throwable se : getSuppressed()) 65551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski se.printEnclosedStackTrace(s, trace, SUPPRESSED_CAPTION, "\t", dejaVu); 65651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 65751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Print cause, if any 65851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Throwable ourCause = getCause(); 65951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (ourCause != null) 66051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski ourCause.printEnclosedStackTrace(s, trace, CAUSE_CAPTION, "", dejaVu); 66151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 66251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 66351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 66451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 66551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Print our stack trace as an enclosed exception for the specified 66651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack trace. 66751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 66851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private void printEnclosedStackTrace(PrintStreamOrWriter s, 66951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski StackTraceElement[] enclosingTrace, 67051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski String caption, 67151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski String prefix, 67251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Set<Throwable> dejaVu) { 67351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (dejaVu.contains(this)) { 67451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.println("\t[CIRCULAR REFERENCE:" + this + "]"); 67551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } else { 67651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski dejaVu.add(this); 67751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Compute number of frames in common between this and enclosing trace 67851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski StackTraceElement[] trace = getOurStackTrace(); 67951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski int m = trace.length - 1; 68051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski int n = enclosingTrace.length - 1; 68151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski while (m >= 0 && n >=0 && trace[m].equals(enclosingTrace[n])) { 68251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski m--; n--; 68351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 68451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski int framesInCommon = trace.length - 1 - m; 68551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 68651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Print our stack trace 68751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.println(prefix + caption + this); 68851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for (int i = 0; i <= m; i++) 68951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.println(prefix + "\tat " + trace[i]); 69051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (framesInCommon != 0) 69151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.println(prefix + "\t... " + framesInCommon + " more"); 69251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 69351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Print suppressed exceptions, if any 69451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for (Throwable se : getSuppressed()) 69551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski se.printEnclosedStackTrace(s, trace, SUPPRESSED_CAPTION, 69651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski prefix +"\t", dejaVu); 69751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 69851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Print cause, if any 69951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Throwable ourCause = getCause(); 70051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (ourCause != null) 70151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski ourCause.printEnclosedStackTrace(s, trace, CAUSE_CAPTION, prefix, dejaVu); 70251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 70351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 70451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 70551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 70651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Prints this throwable and its backtrace to the specified 70751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * print writer. 70851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 70951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param s {@code PrintWriter} to use for output 71051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since JDK1.1 71151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 71251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public void printStackTrace(PrintWriter s) { 71351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski printStackTrace(new WrappedPrintWriter(s)); 71451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 71551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 71651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 71751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Wrapper class for PrintStream and PrintWriter to enable a single 71851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * implementation of printStackTrace. 71951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 72051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private abstract static class PrintStreamOrWriter { 72151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** Returns the object to be locked when using this StreamOrWriter */ 72251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski abstract Object lock(); 72351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 72451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** Prints the specified string as a line on this StreamOrWriter */ 72551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski abstract void println(Object o); 72651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 72751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 72851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static class WrappedPrintStream extends PrintStreamOrWriter { 72951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private final PrintStream printStream; 73051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 73151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski WrappedPrintStream(PrintStream printStream) { 73251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.printStream = printStream; 73351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 73451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 73551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Object lock() { 73651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return printStream; 73751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 73851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 73951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski void println(Object o) { 74051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski printStream.println(o); 74151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 74251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 74351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 74451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private static class WrappedPrintWriter extends PrintStreamOrWriter { 74551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private final PrintWriter printWriter; 74651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 74751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski WrappedPrintWriter(PrintWriter printWriter) { 74851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.printWriter = printWriter; 74951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 75051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 75151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski Object lock() { 75251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return printWriter; 75351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 75451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 75551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski void println(Object o) { 75651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski printWriter.println(o); 75751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 75851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 75951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 76051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 76151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Fills in the execution stack trace. This method records within this 76251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code Throwable} object information about the current state of 76351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the stack frames for the current thread. 76451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 76551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>If the stack trace of this {@code Throwable} {@linkplain 76651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Throwable#Throwable(String, Throwable, boolean, boolean) is not 76751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * writable}, calling this method has no effect. 76851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 76951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return a reference to this {@code Throwable} instance. 77051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @see java.lang.Throwable#printStackTrace() 77151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 77251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public synchronized Throwable fillInStackTrace() { 77351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (stackTrace != null || 77451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski backtrace != null /* Out of protocol state */ ) { 775de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski backtrace = nativeFillInStackTrace(); 77662431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath stackTrace = libcore.util.EmptyArray.STACK_TRACE_ELEMENT; 77751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 77851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return this; 77951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 78051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 781fa5b565a3f6c6d7cbd6106ee8d360304c3a939a3Igor Murashkin @FastNative 782de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski private static native Object nativeFillInStackTrace(); 78351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 78451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 78551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Provides programmatic access to the stack trace information printed by 78651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #printStackTrace()}. Returns an array of stack trace elements, 78751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * each representing one stack frame. The zeroth element of the array 78851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * (assuming the array's length is non-zero) represents the top of the 78951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack, which is the last method invocation in the sequence. Typically, 79051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * this is the point at which this throwable was created and thrown. 79151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The last element of the array (assuming the array's length is non-zero) 79251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * represents the bottom of the stack, which is the first method invocation 79351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * in the sequence. 79451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 79551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>Some virtual machines may, under some circumstances, omit one 79651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * or more stack frames from the stack trace. In the extreme case, 79751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * a virtual machine that has no stack trace information concerning 79851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * this throwable is permitted to return a zero-length array from this 79951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * method. Generally speaking, the array returned by this method will 80051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * contain one element for every frame that would be printed by 80151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code printStackTrace}. Writes to the returned array do not 80251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * affect future calls to this method. 80351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 80451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return an array of stack trace elements representing the stack trace 80551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * pertaining to this throwable. 80651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 80751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 80851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public StackTraceElement[] getStackTrace() { 80951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return getOurStackTrace().clone(); 81051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 81151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 81251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private synchronized StackTraceElement[] getOurStackTrace() { 81351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Initialize stack trace field with information from 81451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // backtrace if this is the first call to this method 81562431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath // 8166975f84c2ed72e1e26d20190b6f318718c849008Tobias Thierer // Android-changed: test explicitly for equality with 81762431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath // STACK_TRACE_ELEMENT 81862431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath if (stackTrace == libcore.util.EmptyArray.STACK_TRACE_ELEMENT || 81951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski (stackTrace == null && backtrace != null) /* Out of protocol state */) { 82062431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath stackTrace = nativeGetStackTrace(backtrace); 82162431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath backtrace = null; 82251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 82362431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath 8246975f84c2ed72e1e26d20190b6f318718c849008Tobias Thierer // Android-changed: Return an empty element both when the stack trace 82562431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath // isn't writeable and also when nativeGetStackTrace returns null. 82662431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath if (stackTrace == null) { 82762431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath return libcore.util.EmptyArray.STACK_TRACE_ELEMENT; 82862431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath } 82962431a724629f84cd9c45e7bcf2f71c8fdc28f7eNarayan Kamath 83051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return stackTrace; 83151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 83251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 83351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 83451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Sets the stack trace elements that will be returned by 83551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@link #getStackTrace()} and printed by {@link #printStackTrace()} 83651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * and related methods. 83751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 83851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This method, which is designed for use by RPC frameworks and other 83951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * advanced systems, allows the client to override the default 84051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stack trace that is either generated by {@link #fillInStackTrace()} 84151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * when a throwable is constructed or deserialized when a throwable is 84251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * read from a serialization stream. 84351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 84451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>If the stack trace of this {@code Throwable} {@linkplain 84551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Throwable#Throwable(String, Throwable, boolean, boolean) is not 84651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * writable}, calling this method has no effect other than 84751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * validating its argument. 84851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 84951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param stackTrace the stack trace elements to be associated with 85051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * this {@code Throwable}. The specified array is copied by this 85151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * call; changes in the specified array after the method invocation 85251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * returns will have no affect on this {@code Throwable}'s stack 85351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * trace. 85451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 85551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @throws NullPointerException if {@code stackTrace} is 85651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code null} or if any of the elements of 85751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code stackTrace} are {@code null} 85851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 85951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.4 86051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 86151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public void setStackTrace(StackTraceElement[] stackTrace) { 86251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Validate argument 86351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski StackTraceElement[] defensiveCopy = stackTrace.clone(); 86451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for (int i = 0; i < defensiveCopy.length; i++) { 86551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (defensiveCopy[i] == null) 86651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new NullPointerException("stackTrace[" + i + "]"); 86751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 86851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 86951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski synchronized (this) { 87051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (this.stackTrace == null && // Immutable stack 87151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski backtrace == null) // Test for out of protocol state 87251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return; 87351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.stackTrace = defensiveCopy; 87451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 87551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 87651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 87751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 87851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Returns the specified element of the stack trace. 87951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 88051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * package-protection for use by SharedSecrets. 88151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 88251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param index index of the element to return. 88351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @throws IndexOutOfBoundsException if {@code index < 0 || 88451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * index >= getStackTraceDepth() } 88551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 886fa5b565a3f6c6d7cbd6106ee8d360304c3a939a3Igor Murashkin @FastNative 887de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski private static native StackTraceElement[] nativeGetStackTrace(Object stackState); 888de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski 88951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 89051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 89151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Reads a {@code Throwable} from a stream, enforcing 89251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * well-formedness constraints on fields. Null entries and 89351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * self-pointers are not allowed in the list of {@code 89451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressedExceptions}. Null entries are not allowed for stack 89551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * trace elements. A null stack trace in the serial form results 89651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * in a zero-length stack element array. A single-element stack 89751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * trace whose entry is equal to {@code new StackTraceElement("", 89851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * "", null, Integer.MIN_VALUE)} results in a {@code null} {@code 89951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stackTrace} field. 90051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 90151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Note that there are no constraints on the value the {@code 90251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause} field can hold; both {@code null} and {@code this} are 90351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * valid values for the field. 90451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 90551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private void readObject(ObjectInputStream s) 90651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throws IOException, ClassNotFoundException { 90751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.defaultReadObject(); // read in all fields 90851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (suppressedExceptions != null) { 90951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski List<Throwable> suppressed = null; 91051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (suppressedExceptions.isEmpty()) { 91151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Use the sentinel for a zero-length list 912de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski suppressed = Collections.emptyList(); 91351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } else { // Copy Throwables to new list 91451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski suppressed = new ArrayList<>(1); 91551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for (Throwable t : suppressedExceptions) { 91651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Enforce constraints on suppressed exceptions in 91751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // case of corrupt or malicious stream. 91851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (t == null) 91951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new NullPointerException(NULL_CAUSE_MESSAGE); 92051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (t == this) 92151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new IllegalArgumentException(SELF_SUPPRESSION_MESSAGE); 92251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski suppressed.add(t); 92351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 92451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 92551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski suppressedExceptions = suppressed; 92651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } // else a null suppressedExceptions field remains null 92751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 92851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /* 92951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * For zero-length stack traces, use a clone of 93051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * UNASSIGNED_STACK rather than UNASSIGNED_STACK itself to 93151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * allow identity comparison against UNASSIGNED_STACK in 93251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * getOurStackTrace. The identity of UNASSIGNED_STACK in 93351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * stackTrace indicates to the getOurStackTrace method that 93451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the stackTrace needs to be constructed from the information 93551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * in backtrace. 93651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 93751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (stackTrace != null) { 93851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (stackTrace.length == 0) { 93951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } else if (stackTrace.length == 1 && 94051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Check for the marker of an immutable stack trace 94151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski SentinelHolder.STACK_TRACE_ELEMENT_SENTINEL.equals(stackTrace[0])) { 94251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski stackTrace = null; 94351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } else { // Verify stack trace elements are non-null. 94451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski for(StackTraceElement ste : stackTrace) { 94551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (ste == null) 94651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new NullPointerException("null StackTraceElement in serial stream. "); 94751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 94851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 94951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } else { 95051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // A null stackTrace field in the serial form can result 95151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // from an exception serialized without that field in 95251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // older JDK releases; treat such exceptions as having 95351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // empty stack traces. 954de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski stackTrace = new StackTraceElement[0]; 95551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 95651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 95751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 95851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 95951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Write a {@code Throwable} object to a stream. 96051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 96151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * A {@code null} stack trace field is represented in the serial 96251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * form as a one-element array whose element is equal to {@code 96351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * new StackTraceElement("", "", null, Integer.MIN_VALUE)}. 96451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 96551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private synchronized void writeObject(ObjectOutputStream s) 96651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throws IOException { 96751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // Ensure that the stackTrace field is initialized to a 96851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // non-null value, if appropriate. As of JDK 7, a null stack 96951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // trace field is a valid value indicating the stack trace 97051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski // should not be set. 97151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski getOurStackTrace(); 97251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 97351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski StackTraceElement[] oldStackTrace = stackTrace; 97451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski try { 97551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (stackTrace == null) 97651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski stackTrace = SentinelHolder.STACK_TRACE_SENTINEL; 97751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski s.defaultWriteObject(); 97851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } finally { 97951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski stackTrace = oldStackTrace; 98051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 98151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 98251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 98351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 98451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Appends the specified exception to the exceptions that were 98551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed in order to deliver this exception. This method is 98651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * thread-safe and typically called (automatically and implicitly) 98751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * by the {@code try}-with-resources statement. 98851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 98951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>The suppression behavior is enabled <em>unless</em> disabled 99051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@linkplain #Throwable(String, Throwable, boolean, boolean) via 99151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * a constructor}. When suppression is disabled, this method does 99251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * nothing other than to validate its argument. 99351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 99451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>Note that when one exception {@linkplain 99551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #initCause(Throwable) causes} another exception, the first 99651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exception is usually caught and then the second exception is 99751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * thrown in response. In other words, there is a causal 99851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * connection between the two exceptions. 99951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 100051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * In contrast, there are situations where two independent 100151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exceptions can be thrown in sibling code blocks, in particular 100251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * in the {@code try} block of a {@code try}-with-resources 100351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * statement and the compiler-generated {@code finally} block 100451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * which closes the resource. 100551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 100651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * In these situations, only one of the thrown exceptions can be 100751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * propagated. In the {@code try}-with-resources statement, when 100851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * there are two such exceptions, the exception originating from 100951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * the {@code try} block is propagated and the exception from the 101051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * {@code finally} block is added to the list of exceptions 101151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed by the exception from the {@code try} block. As an 101251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * exception unwinds the stack, it can accumulate multiple 101351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed exceptions. 101451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 101551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>An exception may have suppressed exceptions while also being 101651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * caused by another exception. Whether or not an exception has a 101751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * cause is semantically known at the time of its creation, unlike 101851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * whether or not an exception will suppress other exceptions 101951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * which is typically only determined after an exception is 102051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * thrown. 102151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 102251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <p>Note that programmer written code is also able to take 102351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * advantage of calling this method in situations where there are 102451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * multiple sibling exceptions and only one can be propagated. 102551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 102651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param exception the exception to be added to the list of 102751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed exceptions 102851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @throws IllegalArgumentException if {@code exception} is this 102951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * throwable; a throwable cannot suppress itself. 103051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @throws NullPointerException if {@code exception} is {@code null} 103151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.7 103251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 103351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public final synchronized void addSuppressed(Throwable exception) { 103451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (exception == this) 103551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new IllegalArgumentException(SELF_SUPPRESSION_MESSAGE, exception); 103651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 103751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (exception == null) 103851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski throw new NullPointerException(NULL_CAUSE_MESSAGE); 103951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 104051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (suppressedExceptions == null) // Suppressed exceptions not recorded 104151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return; 104251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 1043de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski if (suppressedExceptions.isEmpty()) 104451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski suppressedExceptions = new ArrayList<>(1); 104551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 104651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski suppressedExceptions.add(exception); 104751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 104851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 1049de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski private static Throwable[] EMPTY_THROWABLE_ARRAY; 105051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 105151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 105251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Returns an array containing all of the exceptions that were 105351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed, typically by the {@code try}-with-resources 105451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * statement, in order to deliver this exception. 105551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 105651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * If no exceptions were suppressed or {@linkplain 105751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * #Throwable(String, Throwable, boolean, boolean) suppression is 105851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * disabled}, an empty array is returned. This method is 105951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * thread-safe. Writes to the returned array do not affect future 106051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * calls to this method. 106151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 106251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return an array containing all of the exceptions that were 106351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * suppressed to deliver this exception. 106451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @since 1.7 106551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 106651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public final synchronized Throwable[] getSuppressed() { 1067de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski if (EMPTY_THROWABLE_ARRAY == null) { 1068de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski EMPTY_THROWABLE_ARRAY = new Throwable[0]; 1069de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski } 1070de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski 1071de626ec8a109ea18283d96c720cc57e2f32f67faPiotr Jastrzebski if (suppressedExceptions == null || suppressedExceptions.isEmpty()) 107251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return EMPTY_THROWABLE_ARRAY; 107351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski else 107451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return suppressedExceptions.toArray(EMPTY_THROWABLE_ARRAY); 107551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 107651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski} 1077