| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.harmony.luni.util; |
| |
| /** |
| * Exploits a weakness in the runtime to throw an arbitrary throwable without |
| * the traditional declaration. <strong>This is a dangerous API that should be |
| * used with great caution.</strong> Typically this is useful when rethrowing |
| * throwables that are of a known range of types. |
| * |
| * <p>The following code must enumerate several types to rethrow: |
| * <pre> |
| * public void close() throws IOException { |
| * Throwable thrown = null; |
| * ... |
| * |
| * if (thrown != null) { |
| * if (thrown instanceof IOException) { |
| * throw (IOException) thrown; |
| * } else if (thrown instanceof RuntimeException) { |
| * throw (RuntimeException) thrown; |
| * } else if (thrown instanceof Error) { |
| * throw (Error) thrown; |
| * } else { |
| * throw new AssertionError(); |
| * } |
| * } |
| * }</pre> |
| * With SneakyThrow, rethrowing is easier: |
| * <pre> |
| * public void close() throws IOException { |
| * Throwable thrown = null; |
| * ... |
| * |
| * if (thrown != null) { |
| * SneakyThrow.sneakyThrow(thrown); |
| * } |
| * }</pre> |
| */ |
| public final class SneakyThrow { |
| private SneakyThrow() {} |
| |
| public static void sneakyThrow(Throwable t) { |
| SneakyThrow.<Error>sneakyThrow2(t); |
| } |
| |
| /** |
| * Exploits unsafety to throw an exception that the compiler wouldn't permit |
| * but that the runtime doesn't check. See Java Puzzlers #43. |
| */ |
| @SuppressWarnings("unchecked") |
| private static <T extends Throwable> void sneakyThrow2(Throwable t) throws T { |
| throw (T) t; |
| } |
| } |