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.net.UnknownHostException; 20 import libcore.io.Libcore; 21 22 /** 23 * An unchecked exception thrown when {@code getaddrinfo} or {@code getnameinfo} fails. 24 * This exception contains the native {@link #error} value, should sophisticated 25 * callers need to adjust their behavior based on the exact failure. 26 * 27 * @hide 28 */ 29 public final class GaiException extends RuntimeException { 30 private final String functionName; 31 32 /** 33 * The native error value, for comparison with the {@code GAI_} constants in {@link OsConstants}. 34 */ 35 public final int error; 36 37 /** 38 * Constructs an instance with the given function name and error value. 39 */ GaiException(String functionName, int error)40 public GaiException(String functionName, int error) { 41 this.functionName = functionName; 42 this.error = error; 43 } 44 45 /** 46 * Constructs an instance with the given function name, error value, and cause. 47 */ GaiException(String functionName, int error, Throwable cause)48 public GaiException(String functionName, int error, Throwable cause) { 49 super(cause); 50 this.functionName = functionName; 51 this.error = error; 52 } 53 54 /** 55 * Converts the stashed function name and error 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 String gaiName = OsConstants.gaiName(error); 61 if (gaiName == null) { 62 gaiName = "GAI_ error " + error; 63 } 64 String description = Libcore.os.gai_strerror(error); 65 return functionName + " failed: " + gaiName + " (" + description + ")"; 66 } 67 68 /** 69 * @hide - internal use only. 70 */ rethrowAsUnknownHostException(String detailMessage)71 public UnknownHostException rethrowAsUnknownHostException(String detailMessage) throws UnknownHostException { 72 UnknownHostException newException = new UnknownHostException(detailMessage); 73 newException.initCause(this); 74 throw newException; 75 } 76 77 /** 78 * @hide - internal use only. 79 */ rethrowAsUnknownHostException()80 public UnknownHostException rethrowAsUnknownHostException() throws UnknownHostException { 81 throw rethrowAsUnknownHostException(getMessage()); 82 } 83 } 84