11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2010 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.util.concurrent; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static java.util.logging.Level.SEVERE; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.VisibleForTesting; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.lang.Thread.UncaughtExceptionHandler; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.logging.Logger; 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Factories for {@link UncaughtExceptionHandler} instances. 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Gregory Kick 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 8.0 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic final class UncaughtExceptionHandlers { 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private UncaughtExceptionHandlers() {} 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns an exception handler that exits the system. This is particularly useful for the main 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * thread, which may start up other, non-daemon threads, but fail to fully initialize the 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * application successfully. 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>Example usage: 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <pre>public static void main(String[] args) { 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Thread.currentThread().setUncaughtExceptionHandler(UncaughtExceptionHandlers.systemExit()); 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * ... 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * </pre> 450888a09821a98ac0680fad765217302858e70fa4Paul Duffin * 460888a09821a98ac0680fad765217302858e70fa4Paul Duffin * <p>The returned handler logs any exception at severity {@code SEVERE} and then shuts down the 470888a09821a98ac0680fad765217302858e70fa4Paul Duffin * process with an exit status of 1, indicating abnormal termination. 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public static UncaughtExceptionHandler systemExit() { 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return new Exiter(Runtime.getRuntime()); 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 530888a09821a98ac0680fad765217302858e70fa4Paul Duffin @VisibleForTesting static final class Exiter implements UncaughtExceptionHandler { 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static final Logger logger = Logger.getLogger(Exiter.class.getName()); 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final Runtime runtime; 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Exiter(Runtime runtime) { 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.runtime = runtime; 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 620888a09821a98ac0680fad765217302858e70fa4Paul Duffin @Override public void uncaughtException(Thread t, Throwable e) { 630888a09821a98ac0680fad765217302858e70fa4Paul Duffin try { 640888a09821a98ac0680fad765217302858e70fa4Paul Duffin // cannot use FormattingLogger due to a dependency loop 650888a09821a98ac0680fad765217302858e70fa4Paul Duffin logger.log(SEVERE, String.format("Caught an exception in %s. Shutting down.", t), e); 660888a09821a98ac0680fad765217302858e70fa4Paul Duffin } catch (Throwable errorInLogging) { 670888a09821a98ac0680fad765217302858e70fa4Paul Duffin // If logging fails, e.g. due to missing memory, at least try to log the 680888a09821a98ac0680fad765217302858e70fa4Paul Duffin // message and the cause for the failed logging. 690888a09821a98ac0680fad765217302858e70fa4Paul Duffin System.err.println(e.getMessage()); 700888a09821a98ac0680fad765217302858e70fa4Paul Duffin System.err.println(errorInLogging.getMessage()); 710888a09821a98ac0680fad765217302858e70fa4Paul Duffin } finally { 720888a09821a98ac0680fad765217302858e70fa4Paul Duffin runtime.exit(1); 730888a09821a98ac0680fad765217302858e70fa4Paul Duffin } 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 77