1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package libcore.io;
18
19import java.io.IOException;
20import java.net.SocketException;
21
22/**
23 * A checked exception thrown when {@link Os} methods fail. This exception contains the native
24 * errno value, for comparison against the constants in {@link OsConstants}, should sophisticated
25 * callers need to adjust their behavior based on the exact failure.
26 */
27public final class ErrnoException extends Exception {
28    private final String functionName;
29    public final int errno;
30
31    public ErrnoException(String functionName, int errno) {
32        this.functionName = functionName;
33        this.errno = errno;
34    }
35
36    public ErrnoException(String functionName, int errno, Throwable cause) {
37        super(cause);
38        this.functionName = functionName;
39        this.errno = errno;
40    }
41
42    /**
43     * Converts the stashed function name and errno value to a human-readable string.
44     * We do this here rather than in the constructor so that callers only pay for
45     * this if they need it.
46     */
47    @Override public String getMessage() {
48        String errnoName = OsConstants.errnoName(errno);
49        if (errnoName == null) {
50            errnoName = "errno " + errno;
51        }
52        String description = Libcore.os.strerror(errno);
53        return functionName + " failed: " + errnoName + " (" + description + ")";
54    }
55
56    public IOException rethrowAsIOException() throws IOException {
57        IOException newException = new IOException(getMessage());
58        newException.initCause(this);
59        throw newException;
60    }
61
62    public SocketException rethrowAsSocketException() throws SocketException {
63        throw new SocketException(getMessage(), this);
64    }
65}
66