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 * Never writes data. Calls never go beyond this class.
024 * <p>
025 * This output stream has no destination (file/socket etc.) and all bytes written to it are ignored and lost.
026 * </p>
027 */
028public class NullOutputStream extends OutputStream {
029
030    /**
031     * The singleton instance.
032     *
033     * @since 2.12.0
034     */
035    public static final NullOutputStream INSTANCE = new NullOutputStream();
036
037    /**
038     * The singleton instance.
039     *
040     * @deprecated Use {@link #INSTANCE}.
041     */
042    @Deprecated
043    public static final NullOutputStream NULL_OUTPUT_STREAM = INSTANCE;
044
045    /**
046     * Deprecated in favor of {@link #INSTANCE}.
047     *
048     * TODO: Will be private in 3.0.
049     *
050     * @deprecated Use {@link #INSTANCE}.
051     */
052    @Deprecated
053    public NullOutputStream() {
054    }
055
056    /**
057     * Does nothing - output to {@code /dev/null}.
058     *
059     * @param b The bytes to write
060     * @throws IOException never
061     */
062    @Override
063    public void write(final byte[] b) throws IOException {
064        // To /dev/null
065    }
066
067    /**
068     * Does nothing - output to {@code /dev/null}.
069     *
070     * @param b The bytes to write
071     * @param off The start offset
072     * @param len The number of bytes to write
073     */
074    @Override
075    public void write(final byte[] b, final int off, final int len) {
076        // To /dev/null
077    }
078
079    /**
080     * Does nothing - output to {@code /dev/null}.
081     *
082     * @param b The byte to write
083     */
084    @Override
085    public void write(final int b) {
086        // To /dev/null
087    }
088
089}