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