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.Writer;
020
021/**
022 * This {@link Writer} writes all data to the famous <b>/dev/null</b>.
023 * <p>
024 * This <code>Writer</code> has no destination (file/socket etc.) and all
025 * characters written to it are ignored and lost.
026 *
027 */
028public class NullWriter extends Writer {
029
030    /**
031     * A singleton.
032     */
033    public static final NullWriter NULL_WRITER = new NullWriter();
034
035    /**
036     * Constructs a new NullWriter.
037     */
038    public NullWriter() {
039    }
040
041    /**
042     * Does nothing - output to <code>/dev/null</code>.
043     * @param c The character to write
044     * @return this writer
045     * @since 2.0
046     */
047    @Override
048    public Writer append(final char c) {
049        //to /dev/null
050        return this;
051    }
052
053    /**
054     * Does nothing - output to <code>/dev/null</code>.
055     * @param csq The character sequence to write
056     * @param start The index of the first character to write
057     * @param end  The index of the first character to write (exclusive)
058     * @return this writer
059     * @since 2.0
060     */
061    @Override
062    public Writer append(final CharSequence csq, final int start, final int end) {
063        //to /dev/null
064        return this;
065    }
066
067    /**
068     * Does nothing - output to <code>/dev/null</code>.
069     * @param csq The character sequence to write
070     * @return this writer
071     * @since 2.0
072     */
073    @Override
074    public Writer append(final CharSequence csq) {
075        //to /dev/null
076        return this;
077    }
078
079    /**
080     * Does nothing - output to <code>/dev/null</code>.
081     * @param idx The character to write
082     */
083    @Override
084    public void write(final int idx) {
085        //to /dev/null
086    }
087
088    /**
089     * Does nothing - output to <code>/dev/null</code>.
090     * @param chr The characters to write
091     */
092    @Override
093    public void write(final char[] chr) {
094        //to /dev/null
095    }
096
097    /**
098     * Does nothing - output to <code>/dev/null</code>.
099     * @param chr The characters to write
100     * @param st The start offset
101     * @param end The number of characters to write
102     */
103    @Override
104    public void write(final char[] chr, final int st, final int end) {
105        //to /dev/null
106    }
107
108    /**
109     * Does nothing - output to <code>/dev/null</code>.
110     * @param str The string to write
111     */
112    @Override
113    public void write(final String str) {
114        //to /dev/null
115    }
116
117    /**
118     * Does nothing - output to <code>/dev/null</code>.
119     * @param str The string to write
120     * @param st The start offset
121     * @param end The number of characters to write
122     */
123    @Override
124    public void write(final String str, final int st, final int end) {
125        //to /dev/null
126    }
127
128    /** @see java.io.Writer#flush() */
129    @Override
130    public void flush() {
131        //to /dev/null
132    }
133
134    /** @see java.io.Writer#close() */
135    @Override
136    public void close() {
137        //to /dev/null
138    }
139
140}