1 /** 2 * Copyright (C) 2010 Google Inc. 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 com.google.inject.internal; 18 19 20 /** 21 * Rethrows user-code exceptions in wrapped exceptions so that Errors can target the correct 22 * exception. 23 * 24 * @author sameb (at) google.com (Sam Berlin) 25 */ 26 class Exceptions { 27 28 /** 29 * Rethrows the exception (or it's cause, if it has one) directly if possible. 30 * If it was a checked exception, this wraps the exception in a stack trace 31 * with no frames, so that the exception is shown immediately with no frames 32 * above it. 33 */ 34 public static RuntimeException rethrowCause(Throwable throwable) { 35 Throwable cause = throwable; 36 if(cause.getCause() != null) { 37 cause = cause.getCause(); 38 } 39 return rethrow(cause); 40 } 41 42 /** Rethrows the exception. */ 43 public static RuntimeException rethrow(Throwable throwable) { 44 if(throwable instanceof RuntimeException) { 45 throw (RuntimeException)throwable; 46 } else if(throwable instanceof Error) { 47 throw (Error)throwable; 48 } else { 49 throw new UnhandledCheckedUserException(throwable); 50 } 51 } 52 53 /** 54 * A marker exception class that we look for in order to unwrap the exception 55 * into the user exception, to provide a cleaner stack trace. 56 */ 57 static class UnhandledCheckedUserException extends RuntimeException { 58 public UnhandledCheckedUserException(Throwable cause) { 59 super(cause); 60 } 61 } 62 } 63
