1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.io.output; 18 19 import java.io.IOException; 20 import java.io.OutputStream; 21 22 /** 23 * Throws an IOException on all attempts to write to the stream. 24 * <p> 25 * Typically uses of this class include testing for corner cases in methods that accept an output stream and acting as a sentinel value instead of a 26 * {@code null} output stream. 27 * </p> 28 * 29 * @since 1.4 30 */ 31 public class ClosedOutputStream extends OutputStream { 32 33 /** 34 * The singleton instance. 35 * 36 * @since 2.12.0 37 */ 38 public static final ClosedOutputStream INSTANCE = new ClosedOutputStream(); 39 40 /** 41 * The singleton instance. 42 * 43 * @deprecated Use {@link #INSTANCE}. 44 */ 45 @Deprecated 46 public static final ClosedOutputStream CLOSED_OUTPUT_STREAM = INSTANCE; 47 48 /** 49 * Throws an {@link IOException} to indicate that the stream is closed. 50 * 51 * @throws IOException always thrown 52 */ 53 @Override 54 public void flush() throws IOException { 55 throw new IOException("flush() failed: stream is closed"); 56 } 57 58 /** 59 * Throws an {@link IOException} to indicate that the stream is closed. 60 * 61 * @param b ignored 62 * @param off ignored 63 * @param len ignored 64 * @throws IOException always thrown 65 */ 66 @Override 67 public void write(final byte b[], final int off, final int len) throws IOException { 68 throw new IOException("write(byte[], int, int) failed: stream is closed"); 69 } 70 71 /** 72 * Throws an {@link IOException} to indicate that the stream is closed. 73 * 74 * @param b ignored 75 * @throws IOException always thrown 76 */ 77 @Override 78 public void write(final int b) throws IOException { 79 throw new IOException("write(int) failed: stream is closed"); 80 } 81 }