antliscence/src/main/org/apache/tools/ant/taskdefs/StreamPumper.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000,2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.tools.ant.taskdefs;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Copies all data from an input stream to an output stream.
 *
 * @author thomas.haas@softwired-inc.com
 * @since Ant 1.2
 */
public class StreamPumper implements Runnable {

    // TODO: make SIZE and SLEEP instance variables.
    // TODO: add a status flag to note if an error occured in run.

    private final static int SLEEP = 5;
    private final static int SIZE = 128;
    private InputStream is;
    private OutputStream os;
    private boolean finished;

    /**
     * Create a new stream pumper.
     *
     * @param is input stream to read data from
     * @param os output stream to write data to.
     */
    public StreamPumper(InputStream is, OutputStream os) {
        this.is = is;
        this.os = os;
    }


    /**
     * Copies data from the input stream to the output stream.
     *
     * Terminates as soon as the input stream is closed or an error occurs.
     */
    public void run() {
        synchronized (this) {
            // Just in case this object is reused in the future
            finished = false;
        }

        final byte[] buf = new byte[SIZE];

        int length;
        try {
            while ((length = is.read(buf)) > 0) {
                os.write(buf, 0, length);
                try {
                    Thread.sleep(SLEEP);
                } catch (InterruptedException e) {}
            }
        } catch (IOException e) {
        } finally {
            synchronized (this) {
                finished = true;
                notify();
            }
        }
    }

    /**
     * Tells whether the end of the stream has been reached.
     * @return true is the stream has been exhausted.
     **/
    public synchronized boolean isFinished() {
        return finished;
    }

    /**
     * This method blocks until the stream pumper finishes.
     * @see #isFinished()
     **/
    public synchronized void waitFor()
        throws InterruptedException {
        while (!isFinished()) {
            wait();
        }
    }
}