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 libcore.io; 18 19 import java.net.UnknownHostException; 20 import libcore.io.OsConstants; 21 22 /** 23 * An unchecked exception thrown when the {@link Os} {@code getaddrinfo} or {@code getnameinfo} 24 * methods fail. This exception contains the native error value, for comparison against the 25 * {@code GAI_} constants in {@link OsConstants}, should sophisticated 26 * callers need to adjust their behavior based on the exact failure. 27 */ 28 public final class GaiException extends RuntimeException { 29 private final String functionName; 30 public final int error; 31 GaiException(String functionName, int error)32 public GaiException(String functionName, int error) { 33 this.functionName = functionName; 34 this.error = error; 35 } 36 GaiException(String functionName, int error, Throwable cause)37 public GaiException(String functionName, int error, Throwable cause) { 38 super(cause); 39 this.functionName = functionName; 40 this.error = error; 41 } 42 43 /** 44 * Converts the stashed function name and error value to a human-readable string. 45 * We do this here rather than in the constructor so that callers only pay for 46 * this if they need it. 47 */ getMessage()48 @Override public String getMessage() { 49 String gaiName = OsConstants.gaiName(error); 50 if (gaiName == null) { 51 gaiName = "GAI_ error " + error; 52 } 53 String description = Libcore.os.gai_strerror(error); 54 return functionName + " failed: " + gaiName + " (" + description + ")"; 55 } 56 rethrowAsUnknownHostException(String detailMessage)57 public UnknownHostException rethrowAsUnknownHostException(String detailMessage) throws UnknownHostException { 58 UnknownHostException newException = new UnknownHostException(detailMessage); 59 newException.initCause(this); 60 throw newException; 61 } 62 rethrowAsUnknownHostException()63 public UnknownHostException rethrowAsUnknownHostException() throws UnknownHostException { 64 throw rethrowAsUnknownHostException(getMessage()); 65 } 66 } 67