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 17 // [ravenwood] Copied from libcore. 18 19 package android.system; 20 21 import java.io.IOException; 22 import java.net.SocketException; 23 24 /** 25 * A checked exception thrown when {@link Os} methods fail. This exception contains the native 26 * errno value, for comparison against the constants in {@link OsConstants}, should sophisticated 27 * callers need to adjust their behavior based on the exact failure. 28 */ 29 public final class ErrnoException extends Exception { 30 private final String functionName; 31 32 /** 33 * The errno value, for comparison with the {@code E} constants in {@link OsConstants}. 34 */ 35 public final int errno; 36 37 /** 38 * Constructs an instance with the given function name and errno value. 39 */ ErrnoException(String functionName, int errno)40 public ErrnoException(String functionName, int errno) { 41 this.functionName = functionName; 42 this.errno = errno; 43 } 44 45 /** 46 * Constructs an instance with the given function name, errno value, and cause. 47 */ ErrnoException(String functionName, int errno, Throwable cause)48 public ErrnoException(String functionName, int errno, Throwable cause) { 49 super(cause); 50 this.functionName = functionName; 51 this.errno = errno; 52 } 53 54 /** 55 * Converts the stashed function name and errno value to a human-readable string. 56 * We do this here rather than in the constructor so that callers only pay for 57 * this if they need it. 58 */ getMessage()59 @Override public String getMessage() { 60 return functionName + " failed: " + errno; 61 } 62 63 /** 64 * Throws an {@link IOException} with a message based on {@link #getMessage()} and with this 65 * instance as the cause. 66 * 67 * <p>This method always terminates by throwing the exception. Callers can write 68 * {@code throw e.rethrowAsIOException()} to make that clear to the compiler. 69 */ rethrowAsIOException()70 public IOException rethrowAsIOException() throws IOException { 71 IOException newException = new IOException(getMessage()); 72 newException.initCause(this); 73 throw newException; 74 } 75 76 /** 77 * Throws a {@link SocketException} with a message based on {@link #getMessage()} and with this 78 * instance as the cause. 79 * 80 * <p>This method always terminates by throwing the exception. Callers can write 81 * {@code throw e.rethrowAsIOException()} to make that clear to the compiler. 82 */ rethrowAsSocketException()83 public SocketException rethrowAsSocketException() throws SocketException { 84 throw new SocketException(getMessage()); 85 } 86 } 87