Glassfish example source code file (JvmOptionBag.java)

This example Glassfish source code file (JvmOptionBag.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

bean, configbeanproxy, ducktyped, ducktyped, element, g, i, javabean, jvmoptionbag, k, list, list, string, string, util, xms, xmx

The Glassfish JvmOptionBag.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.config.serverbeans;

import org.jvnet.hk2.config.Element;
import org.jvnet.hk2.config.DuckTyped;
import org.jvnet.hk2.config.ConfigBeanProxy;
import org.jvnet.hk2.config.types.PropertyBag; //used only for Javadoc purpose {@link}
import java.util.List;
import java.beans.PropertyVetoException;

/** Factored out the list of jvm-options from at least two other interfaces that have them: java-config and profiler.
 *  Similar to {@link PropertyBag}
 */
public interface JvmOptionBag extends ConfigBeanProxy {
    @Element
    public List<String> getJvmOptions();

    void setJvmOptions(List<String> options) throws PropertyVetoException;

    /** It's observed that many a time we need the value of max heap size. This is useful when deciding if a
     *  user is misconfiguring the JVM by specifying -Xmx that is smaller than -Xms. Sun's JVM for example,
     *  bails out with <code> Incompatible minimum and maximum heap sizes specified when that happens. 
     *  It's generally better to do some basic validations in those cases and that's when this method may be useful.
     * @return an integer specifying the actual max heap memory (-Xmx) configured. If it's specified as -Xmx2g, then 2*1024
     * i.e. 2048 is returned. Returns -1 if no -Xmx is specified.
     */
    @DuckTyped
    int getXmxMegs();

    /** see #getXmxMegs
     * @return integer specifying -Xms in megabytes, or -1*/
    @DuckTyped
    int getXmsMegs();

    @DuckTyped
    boolean contains(String option);

    @DuckTyped
    String getStartingWith(String start);

    class Duck {
     /* Note: It does not take defaults into account. Also,
     * I have tested that server does not start with a heap that is less than 1m, so I think I don't have to worry about
     * -Xmx that is specified to be less than 1 MB. Again, there is lots and lots of platform dependent code here,
     *  so this check should be minimal. Again, I am doing this kind of check here because while testing, I was
     *  able to get into a situation where -Xmx is configured smaller than -Xms and the server won't start. The user
     *  then must edit the domain.xml by hand!
     */
         public static int getXmxMegs(JvmOptionBag me) {
             return getMemory(me, "-Xmx");
         }
         public static int getXmsMegs(JvmOptionBag me) {
           return getMemory(me, "-Xms");
         }

        private static int getMemory(JvmOptionBag me, String which) {
            List<String> options = me.getJvmOptions();
            for (String opt : options) {
                if(opt.indexOf(which) >= 0) {
                    return toMeg(opt, which);
                }
            }
            return -1;
        }

        public static int toMeg(String whole, String which) {
            String first  = whole.substring(0, which.length());
            String second = whole.substring(which.length());
            if (first == null || second == null)
                return -1;
            char unit = second.charAt(second.length()-1);
            try {
                if (unit =='g' || unit == 'G')
                    return Integer.parseInt(second.substring(0, second.length()-1)) * 1024; //I don't think we'll have an overflow
                else if (unit == 'm' || unit == 'M')
                    return Integer.parseInt(second.substring(0, second.length()-1));
                else if (unit == 'k' || unit == 'K')
                    return Integer.parseInt(second.substring(0, second.length()-1)) / 1024; //beware, integer division
                else
                    return Integer.parseInt(second) / (1024*1024); //bytes, this is a rare case, hopefully -- who does -Xmx1073741824 to specify a meg?
            } catch(NumberFormatException e) {
                //squelch all exceptions
                return -1;
            } catch(RuntimeException e) {
                //squelch all exceptions
                return -1;
            }
        }

        public static boolean contains(JvmOptionBag me, String opt) {
            return me.getJvmOptions().contains(opt);
        }

        public static String getStartingWith(JvmOptionBag me, String start) {
            List<String> opts = me.getJvmOptions();
            for (String opt : opts) {
                if (opt.startsWith(start))
                    return opt;
            }
            return null;
        }
    }
}