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.commons.exec;
019
020import java.io.InputStream;
021import java.io.OutputStream;
022
023import org.apache.commons.exec.util.DebugUtils;
024
025/**
026 * Copies all data from an System.input stream to an output stream of the executed process.
027 */
028public class InputStreamPumper implements Runnable {
029
030    /**
031     * Sleep time in milliseconds.
032     */
033    public static final int SLEEPING_TIME = 100;
034
035    /** The input stream to pump from. */
036    private final InputStream is;
037
038    /** The output stream to pmp into. */
039    private final OutputStream os;
040
041    /** Flag to stop the stream pumping. */
042    private volatile boolean stop;
043
044    /**
045     * Create a new stream pumper.
046     *
047     * @param is input stream to read data from.
048     * @param os output stream to write data to.
049     */
050    public InputStreamPumper(final InputStream is, final OutputStream os) {
051        this.is = is;
052        this.os = os;
053        this.stop = false;
054    }
055
056    /**
057     * Copies data from the input stream to the output stream. Terminates as soon as the input stream is closed or an error occurs.
058     */
059    @Override
060    public void run() {
061        try {
062            while (!stop) {
063                while (is.available() > 0 && !stop) {
064                    os.write(is.read());
065                }
066                os.flush();
067                Thread.sleep(SLEEPING_TIME);
068            }
069        } catch (final Exception e) {
070            final String msg = "Got exception while reading/writing the stream";
071            DebugUtils.handleException(msg, e);
072        }
073    }
074
075    /**
076     * Requests processing to stop.
077     */
078    public void stopProcessing() {
079        stop = true;
080    }
081
082}