| /* |
| * 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.commons.io.output; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.Serializable; |
| import java.util.UUID; |
| |
| import org.apache.commons.io.TaggedIOException; |
| |
| /** |
| * An output stream decorator that tags potential exceptions so that the |
| * stream that caused the exception can easily be identified. This is |
| * done by using the {@link TaggedIOException} class to wrap all thrown |
| * {@link IOException}s. See below for an example of using this class. |
| * <pre> |
| * TaggedOutputStream stream = new TaggedOutputStream(...); |
| * try { |
| * // Processing that may throw an IOException either from this stream |
| * // or from some other IO activity like temporary files, etc. |
| * writeToStream(stream); |
| * } catch (IOException e) { |
| * if (stream.isCauseOf(e)) { |
| * // The exception was caused by this stream. |
| * // Use e.getCause() to get the original exception. |
| * } else { |
| * // The exception was caused by something else. |
| * } |
| * } |
| * </pre> |
| * <p> |
| * Alternatively, the {@link #throwIfCauseOf(Exception)} method can be |
| * used to let higher levels of code handle the exception caused by this |
| * stream while other processing errors are being taken care of at this |
| * lower level. |
| * <pre> |
| * TaggedOutputStream stream = new TaggedOutputStream(...); |
| * try { |
| * writeToStream(stream); |
| * } catch (IOException e) { |
| * stream.throwIfCauseOf(e); |
| * // ... or process the exception that was caused by something else |
| * } |
| * </pre> |
| * |
| * @see TaggedIOException |
| * @since Commons IO 2.0 |
| */ |
| public class TaggedOutputStream extends ProxyOutputStream { |
| |
| /** |
| * The unique tag associated with exceptions from stream. |
| */ |
| private final Serializable tag = UUID.randomUUID(); |
| |
| /** |
| * Creates a tagging decorator for the given output stream. |
| * |
| * @param proxy output stream to be decorated |
| */ |
| public TaggedOutputStream(OutputStream proxy) { |
| super(proxy); |
| } |
| |
| /** |
| * Tests if the given exception was caused by this stream. |
| * |
| * @param exception an exception |
| * @return <code>true</code> if the exception was thrown by this stream, |
| * <code>false</code> otherwise |
| */ |
| public boolean isCauseOf(Exception exception) { |
| return TaggedIOException.isTaggedWith(exception, tag); |
| } |
| |
| /** |
| * Re-throws the original exception thrown by this stream. This method |
| * first checks whether the given exception is a {@link TaggedIOException} |
| * wrapper created by this decorator, and then unwraps and throws the |
| * original wrapped exception. Returns normally if the exception was |
| * not thrown by this stream. |
| * |
| * @param exception an exception |
| * @throws IOException original exception, if any, thrown by this stream |
| */ |
| public void throwIfCauseOf(Exception exception) throws IOException { |
| TaggedIOException.throwCauseIfTaggedWith(exception, tag); |
| } |
| |
| /** |
| * Tags any IOExceptions thrown, wrapping and re-throwing. |
| * |
| * @param e The IOException thrown |
| * @throws IOException if an I/O error occurs |
| */ |
| @Override |
| protected void handleIOException(IOException e) throws IOException { |
| throw new TaggedIOException(e, tag); |
| } |
| |
| } |