001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.io.output; 018 019import java.io.IOException; 020import java.io.OutputStream; 021 022/** 023 * Closed output stream. This stream throws an exception on all attempts to 024 * write something to the stream. 025 * <p> 026 * Typically uses of this class include testing for corner cases in methods 027 * that accept an output stream and acting as a sentinel value instead of 028 * a {@code null} output stream. 029 * 030 * @version $Id: ClosedOutputStream.java 1471767 2013-04-24 23:24:19Z sebb $ 031 * @since 1.4 032 */ 033public class ClosedOutputStream extends OutputStream { 034 035 /** 036 * A singleton. 037 */ 038 public static final ClosedOutputStream CLOSED_OUTPUT_STREAM = new ClosedOutputStream(); 039 040 /** 041 * Throws an {@link IOException} to indicate that the stream is closed. 042 * 043 * @param b ignored 044 * @throws IOException always thrown 045 */ 046 @Override 047 public void write(final int b) throws IOException { 048 throw new IOException("write(" + b + ") failed: stream is closed"); 049 } 050 051}