src/main/org/apache/tools/ant/taskdefs/PumpStreamHandler.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 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
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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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.InputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * Copies standard output and error of subprocesses to standard output and
 * error of the parent process.
 *
 * TODO: standard input of the subprocess is not implemented.
 *
 * @author thomas.haas@softwired-inc.com
 */
public class PumpStreamHandler implements ExecuteStreamHandler {

    private Thread inputThread;
    private Thread errorThread;

    private OutputStream out, err;

    public PumpStreamHandler(OutputStream out, OutputStream err) {
        this.out = out;
        this.err = err;
    }

    public PumpStreamHandler(OutputStream outAndErr) {
        this(outAndErr, outAndErr);
    }

    public PumpStreamHandler() {
        this(System.out, System.err);
    }

    public void setProcessOutputStream(InputStream is) {
        createProcessOutputPump(is, out);
    }


    public void setProcessErrorStream(InputStream is) {
        createProcessErrorPump(is, err);
    }


    public void setProcessInputStream(OutputStream os) {
    }


    public void start() {
        inputThread.start();
        errorThread.start();
    }


    public void stop() {
        try {
            inputThread.join();
        } catch(InterruptedException e) {}
        try {
            errorThread.join();
        } catch(InterruptedException e) {}
        try {
            err.flush();
        } catch (IOException e) {}
        try {
            out.flush();
        } catch (IOException e) {}
    }

    protected OutputStream getErr() {
        return err;
    }

    protected OutputStream getOut() {
        return out;
    }

    protected void createProcessOutputPump(InputStream is, OutputStream os) {
        inputThread = createPump(is, os);
    }

    protected void createProcessErrorPump(InputStream is, OutputStream os) {
        errorThread = createPump(is, os);
    }


    /**
     * Creates a stream pumper to copy the given input stream to the given output stream.
     */
    protected Thread createPump(InputStream is, OutputStream os) {
        final Thread result = new Thread(new StreamPumper(is, os));
        result.setDaemon(true);
        return result;
    }

}