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 */
017
018package org.apache.logging.log4j.core.util;
019
020import java.io.IOException;
021import java.io.OutputStream;
022
023/**
024 * Writes all data to the famous <b>/dev/null</b>.
025 * <p>
026 * This output stream has no destination (file/socket etc.) and all bytes written to it are ignored and lost.
027 * </p>
028 * Originally from Apache Commons IO.
029 *
030 * @since 2.3
031 */
032public class NullOutputStream extends OutputStream {
033
034    private static final NullOutputStream INSTANCE = new NullOutputStream();
035
036    /**
037     * @deprecated Deprecated in 2.7: use {@link #getInstance()}.
038     */
039    @Deprecated
040    public static final NullOutputStream NULL_OUTPUT_STREAM = INSTANCE;
041
042    /**
043     * Gets the singleton instance.
044     *
045     * @return the singleton instance.
046     */
047    public static NullOutputStream getInstance() {
048        return INSTANCE;
049    }
050
051    private NullOutputStream() {
052        // do nothing
053    }
054
055    /**
056     * Does nothing - output to <code>/dev/null</code>.
057     *
058     * @param b
059     *        The bytes to write
060     * @param off
061     *        The start offset
062     * @param len
063     *        The number of bytes to write
064     */
065    @Override
066    public void write(final byte[] b, final int off, final int len) {
067        // to /dev/null
068    }
069
070    /**
071     * Does nothing - output to <code>/dev/null</code>.
072     *
073     * @param b
074     *        The byte to write
075     */
076    @Override
077    public void write(final int b) {
078        // to /dev/null
079    }
080
081    /**
082     * Does nothing - output to <code>/dev/null</code>.
083     *
084     * @param b
085     *        The bytes to write
086     * @throws IOException
087     *         never
088     */
089    @Override
090    public void write(final byte[] b) throws IOException {
091        // to /dev/null
092    }
093}