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Apache CXF example source code file (ForkedCommand.java)

This example Apache CXF source code file (ForkedCommand.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Apache CXF tags/keywords

forkedcommand, forkedcommandstreamhandler, forkedcommandstreamhandler, interruptedexception, io, log, log, logging, message, printstream, printstream, process, string, string, stringbuilder, util, waiting

The Apache CXF ForkedCommand.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.cxf.common.commands;

import java.io.*;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.cxf.common.i18n.Message;
import org.apache.cxf.common.logging.LogUtils;


public class ForkedCommand extends Thread {
    public static final String EXE_SUFFIX;
    public static final int DEFAULT_TIMEOUT = 0;
    private static final Logger LOG = LogUtils.getL7dLogger(ForkedCommand.class);
    private String[] arguments;
    private String[] environment;
    private PrintStream outputStream;
    private PrintStream errorStream;
    private java.lang.Process proc;
    private boolean completed;
    private boolean killed;
    private boolean joinErrOut = true;

    static {
        if (System.getProperty("os.name").startsWith("Windows")) {
            EXE_SUFFIX = ".exe";
        } else {
            EXE_SUFFIX = "";
        }
    }
    public ForkedCommand() {
    }

    public ForkedCommand(String[] args) {
        arguments = args;
    }

    protected void setArgs(String[] args) {
        arguments = args;
    }

    public void setEnvironment(String[] env) {
        environment = env;
    }

    public String toString() {
        if (null == arguments) {
            return "";
        }
        StringBuilder buf = new StringBuilder();
        for (int i = 0; i < arguments.length; i++) {
            if (i > 0) {
                buf.append(" ");
            }
            boolean quotesNeeded = false;
            if (arguments[i] != null) {
                StringTokenizer st = new StringTokenizer(arguments[i]);
                quotesNeeded = st.countTokens() > 1;
            }
            if (quotesNeeded) {
                buf.append("\"");
            }
            buf.append(arguments[i]);
            if (quotesNeeded) {
                buf.append("\"");
            }
        }
        return buf.length() > 0 ? buf.toString() : "";
    }

    /**
     * Determines if the threads collecting the forked process' stdout/stderr
     * should be joined.
     * 
     * @param flag boolean indicating if threads should be joined
     */
    public void joinErrOut(boolean flag) {
        this.joinErrOut = flag;
    }

    public int execute() {
        return execute(DEFAULT_TIMEOUT);
    }

    /**
     * Executes the process. If the process has not completed after the
     * specified amount of seconds, it is killed.
     * 
     * @param timeout the timeout in seconds
     * @throws ForkedCommandException if process execution fails for some reason
     *             or if the timeout has expired and the process was killed
     */
    public int execute(int timeout) {
        if (null == arguments || arguments.length == 0) {
            throw new ForkedCommandException(new Message("NO_ARGUMENTS_EXC", LOG));
        }
        if (LOG.isLoggable(Level.FINE)) {
            LOG.fine("Executing command: " + this);
        }
        try {
            Runtime rt = Runtime.getRuntime();
            if (environment == null) {
                proc = rt.exec(arguments);
            } else {
                if (LOG.isLoggable(Level.FINE)) {
                    StringBuilder msg = new StringBuilder();
                    msg.append("Process environment: ");

                    for (int i = 0; i < environment.length; i++) {
                        msg.append(environment[i]);
                        msg.append(" ");
                    }
                    LOG.fine(msg.toString());
                }

                proc = rt.exec(arguments, environment);
            }
        } catch (IOException ex) {
            throw new ForkedCommandException(new Message("EXECUTE_EXC", LOG, this), ex);
        }

        // catch process stderr/stdout
        ForkedCommandStreamHandler cmdOut = new ForkedCommandStreamHandler(proc.getInputStream(),
                                                                           outputStream == null
                                                                               ? System.out : outputStream);
        ForkedCommandStreamHandler cmdErr = new ForkedCommandStreamHandler(proc.getErrorStream(),
                                                                           errorStream == null
                                                                               ? System.err : errorStream);
        cmdErr.start();
        cmdOut.start();

        // now wait for the process on our own thread
        start();

        // kill process after timeout
        try {
            if (timeout > 0) {
                if (LOG.isLoggable(Level.FINE)) {
                    LOG.fine("Waiting " + timeout + " seconds for process to complete");
                }
                join(timeout * 1000);
            } else {
                if (LOG.isLoggable(Level.FINE)) {
                    LOG.fine("Waiting for process to complete");
                }
                join();
            }
        } catch (InterruptedException ex) {
            ex.printStackTrace();
        } finally {
            if (completed) {
                if (LOG.isLoggable(Level.FINE)) {
                    LOG.fine("Process completed in time");
                }
            } else {
                proc.destroy();
                killed = true;
                LOG.fine("Process timed out and was killed");
            }

            // wait for the streams threads to finish if necessary
            if (joinErrOut) {
                if (LOG.isLoggable(Level.FINE)) {
                    LOG.info("Waiting a further 10 seconds for process "
                                 + " stdout/stderr streams to be flushed");
                }
                try {
                    cmdErr.join(10 * 1000);
                    cmdOut.join(10 * 1000);
                } catch (InterruptedException ex) {
                    // silently ignore
                }
            }
        }

        if (killed) {
            throw new ForkedCommandException(new Message("TIMEOUT_EXC", LOG, timeout));
        }
        int exitVal = proc.exitValue();
        if (LOG.isLoggable(Level.FINE)) {
            LOG.fine("Process exited with value: " + exitVal);
        }

        return exitVal;
    }

    /**
     * Implements the run method for the thread on which the process is
     * executed.
     */
    public void run() {
        try {
            proc.waitFor();
            completed = true;
        } catch (InterruptedException ex) {
            // ignore this one
            ex.printStackTrace();
        }
    }

    public void setOutputStream(PrintStream os) {
        outputStream = os;
    }

    public void setErrorStream(PrintStream es) {
        errorStream = es;
    }
}

class ForkedCommandStreamHandler extends Thread {

    private final InputStream is;
    private final PrintStream ps;

    ForkedCommandStreamHandler(InputStream i, PrintStream p) {
        is = i;
        ps = p;
    }

    public void run() {
        try {
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String line = br.readLine();
            while (line != null) {
                ps.println(line);
                line = br.readLine();
            }
        } catch (IOException ioe) {
            // ignore
        }
    }
}

Other Apache CXF examples (source code examples)

Here is a short list of links related to this Apache CXF ForkedCommand.java source code file:

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