Glassfish example source code file (Jps.java)

This example Glassfish source code file (Jps.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 - Glassfish tags/keywords

exception, file, file, hashmap, integer, integer, io, jps, jps, map, processmanager, string, string, util

The Glassfish Jps.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.enterprise.universal.process;

import java.io.*;
import java.util.*;

import com.sun.enterprise.universal.io.SmartFile;
import com.sun.enterprise.util.OS;

import static com.sun.enterprise.util.StringUtils.ok;

/**
 * Run a native process with jps
 * -- get the pid for a running JVM
 * note:  dropping in an implementation for jps is not hard.
 * @author bnevins
 */
public class Jps {

    public static void main(String[] args) {
        Set<Map.Entry set = getProcessTable().entrySet();
        System.out.println("** Got " + set.size() + " process entries");
        for (Map.Entry<String, Integer> e : set) {
            System.out.printf("%d %s\n", e.getValue(), e.getKey());
        }
    }

    final static public Map<String, Integer> getProcessTable() {
        return new Jps().pidMap;
    }

    /**
     * return the platform-specific process-id of a JVM
     * @param mainClassName The main class - this is how we identify the right JVM
     * @return the process id if possible otherwise 0
     */
    final static public int getPid(String mainClassName) {
        Jps jps = new Jps();
        Integer integer = jps.pidMap.get(mainClassName);

        if (integer == null) {
            return 0;
        }

        return integer;
    }

    /**
     * Is this pid owned by a process?
     * @param apid the pid of interest
     * @return whether there is a process running with that id
     */
    final static public boolean isPid(int apid) {
        return new Jps().pidMap.containsValue(apid);
    }

    private Jps() {
        try {
            if (jpsExe == null) {
                return;
            }
            ProcessManager pm = new ProcessManager(jpsExe.getPath(), "-l");
            pm.setEcho(false);
            pm.execute();
            String jpsOutput = pm.getStdout();

            // get each line
            String[] ss = jpsOutput.split("[\n\r]");

            for (String line : ss) {
                if (line == null || line.length() <= 0) {
                    continue;
                }

                String[] sublines = line.split(" ");
                if (sublines == null || sublines.length != 2) {
                    continue;
                }

                int aPid = 0;
                try {
                    aPid = Integer.parseInt(sublines[0]);
                } catch (Exception e) {
                    continue;
                }
                // todo -- handle duplicate names??
                // todo -- easy --> make the pid the key not the value!
                if (!isJps(sublines[1])) {
                    pidMap.put(sublines[1], aPid);
                }
            }
        } catch (Exception e) {
        }
    }

    private boolean isJps(String id) {
        if (!ok(id)) {
            return false;
        }

        if (id.equals(getClass().getName())) {
            return true;
        }

        if (id.equals("sun.tools.jps.Jps")) {
            return true;
        }

        return false;
    }
    private Map<String, Integer> pidMap = new HashMap();
    private static final File jpsExe;
    private static final String jpsName;

    static {
        if (OS.isWindows()) {
            jpsName = "jps.exe";
        } else {
            jpsName = "jps";
        }

        final String javaroot = System.getProperty("java.home");
        final String relpath = "/bin/" + jpsName;
        final File fhere = new File(javaroot + relpath);
        File fthere = new File(javaroot + "/.." + relpath);

        if (fhere.isFile()) {
            jpsExe = SmartFile.sanitize(fhere);
        } else if (fthere.isFile()) {
            jpsExe = SmartFile.sanitize(fthere);
        } else {
            jpsExe = null;
        }
    }
}