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 * Throws an IOException on all attempts to write to the stream.
024 * <p>
025 * 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
026 * {@code null} output stream.
027 * </p>
028 *
029 * @since 1.4
030 */
031public class ClosedOutputStream extends OutputStream {
032
033    /**
034     * The singleton instance.
035     *
036     * @since 2.12.0
037     */
038    public static final ClosedOutputStream INSTANCE = new ClosedOutputStream();
039
040    /**
041     * The singleton instance.
042     *
043     * @deprecated Use {@link #INSTANCE}.
044     */
045    @Deprecated
046    public static final ClosedOutputStream CLOSED_OUTPUT_STREAM = INSTANCE;
047
048    /**
049     * Throws an {@link IOException} to indicate that the stream is closed.
050     *
051     * @throws IOException always thrown
052     */
053    @Override
054    public void flush() throws IOException {
055        throw new IOException("flush() failed: stream is closed");
056    }
057
058    /**
059     * Throws an {@link IOException} to indicate that the stream is closed.
060     *
061     * @param b   ignored
062     * @param off ignored
063     * @param len ignored
064     * @throws IOException always thrown
065     */
066    @Override
067    public void write(final byte b[], final int off, final int len) throws IOException {
068        throw new IOException("write(byte[], int, int) failed: stream is closed");
069    }
070
071    /**
072     * Throws an {@link IOException} to indicate that the stream is closed.
073     *
074     * @param b ignored
075     * @throws IOException always thrown
076     */
077    @Override
078    public void write(final int b) throws IOException {
079        throw new IOException("write(int) failed: stream is closed");
080    }
081}