executor.java

实现了Jms的服务器源码,支持多种适配器,DB,FTP,支持多种数据库

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 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
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 *    copy of this document.
 *
 * 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.
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 * 3. The name "Exolab" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of Exoffice Technologies.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "Exolab"
 *    nor may "Exolab" appear in their names without prior written
 *    permission of Exoffice Technologies. Exolab is a registered
 *    trademark of Exoffice Technologies.
 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
 * ``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 DISCLAIMED.  IN NO EVENT SHALL
 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND 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.
 *
 * Copyright 2001 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: Executor.java,v 1.4 2001/09/06 05:30:34 jima Exp $
 *
 * Date         Author  Changes
 * 09/06/2001   jima    Created from Tim Andersons work on Compliance
 *                      Test Suite.
 */
package org.exolab.testharness.jms.util;

// java io
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;


/**
 * This class enables commands to be executed, with the output being
 * captured, or echoed to System.out and System.err
 *
 * @version     $Revision: 1.4 $ $Date: 2001/09/06 05:30:34 $
 * @author      <a href="mailto:[e-mail]">Tim Anderson</a>
 */
public class Executor {

    /**
     * The command to execute
     */
    private final String _command;

    /**
     * The stream to direct standard out to
     */
    private final OutputStream _out;

    /**
     * The stream to direct standard err to
     */
    private final OutputStream _err;

    /**
     * Reference to the executing process
     */
    private volatile Process _process = null;

    /**
     * Constructor to execute a command, with output going to System.out and 
     * System.err
     *
     * @param command the command to execute
     */
    public Executor(String command) {
        this(command, System.out, System.err);
    }

    /**
     * Constructor to execute a command, with all output going to a stream
     *
     * @param command the command to execute
     * @param log the stream to log output to
     */
    public Executor(String command, OutputStream log) {
        this(command, log, log);
    }

    /**
     * Constructor to execute a command with standard output and error output
     * going to two separate streams
     *
     * @param command the command to execute
     * @param out the stream to direct standard output to
     * @param err the stream to direct standard error to
     */
    public Executor(String command, OutputStream out, OutputStream err) {
        if (command == null) {
            throw new IllegalArgumentException("Argument command is null");
        }
        if (out == null) {
            throw new IllegalArgumentException("Argument out is null");
        }
        if (err == null) {
            throw new IllegalArgumentException("Argument err is null");
        }
        _command = command;
        _out = out;
        _err = err;
    }

    /**
     * Execute the command
     *
     * @return the command exit status
     * @throws Exception if the command cannot be executed
     */
    public int run() throws Exception {
        Thread outStream = null;
        Thread errStream = null;
        boolean done = false;
        int status = 1;

        try {
            _process = Runtime.getRuntime().exec(_command);
            Reader out = new Reader(_process.getInputStream(), _out);
            Reader err = new Reader(_process.getErrorStream(), _err);
            outStream = new Thread(out);
            errStream = new Thread(err);
                                          
            outStream.start();
            errStream.start();
        
            while (!done) {
                try {
                    status = _process.waitFor();
                    done = true;
                } catch (InterruptedException ignore) {
                }
            }
        } catch (Exception error) {
            if (_process != null && !done) {
                _process.destroy();
            }
            if (outStream != null) {
                boolean stopped = false;
                while (!stopped) {
                    try {
                        outStream.join();
                        stopped = true;
                    } catch (InterruptedException ignore) {
                    }
                }
            }
            if (errStream != null) {
                boolean stopped = false;
                while (!stopped) {
                    try {
                        errStream.join();
                        stopped = true;
                    } catch (InterruptedException ignore) {
                    }
                }
            }
            throw error;
        } finally {
            outStream = null;
            errStream = null;
            _process = null;
        }

        return status;
    }

    /**
     * Stop the process
     */
    public void stop() {
        if (_process != null) {
            _process.destroy();
        }
    }

} // End Executor


/**
 * Helper class that reads from one stream and writes to another, in a
 * separate thread.
 */
class Reader implements Runnable {

    /**
     * The thread executing the reader instance
     */
    private volatile Thread _thread = null;

    /**
     * The input stream
     */
    private BufferedReader _input = null;

    /**
     * The output stream
     */
    private PrintStream _output = null;

    /**
     * The exception, if an exception was generated while performing I/O
     */
    private Exception _exception = null;

    /**
     * Construct a reader, reading from the input stream and writing to the 
     * output stream
     *
     * @param input the input stream
     * @param output the output stream
     */
    public Reader(InputStream input, OutputStream output) {
        _input = new BufferedReader(new InputStreamReader(input));
        _output = new PrintStream(output);
    }

    /**
     * Run the reader
     */
    public void run() {
        _thread = Thread.currentThread();
        String line;
        try {
            while (_thread != null && (line = _input.readLine()) != null) {
                _output.println(line);
            }
        }
        catch (IOException error) {
            // terminate this on an I/O error.
            _exception = error;
            _thread = null;
        }
        _input = null;
        _output = null;
    }    

    /**
     * Stop the reader
     */
    public void stop() {
        if (_thread != null) {
            Thread interrupter = _thread;
            _thread = null;
            interrupter.interrupt();
        }
    }

    /**
     * Returns the exception if one was generated. If {@link #stop} was invoked
     * then an exception is likely to have been generated.
     */
    public Exception getException() {
        return _exception;
    }

} // End Reader