JVM.java Source code

Introduction

Here is the source code for JVM.java

Source

/*
 * $Id: JVM.java,v 1.3 2009/02/22 02:01:04 kschaefe Exp $
 *
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

import javax.swing.UIManager;
import javax.swing.UIManager.LookAndFeelInfo;

/**
 * Deals with the different version of the Java Virtual Machine. <br>
 */
public class JVM {

    public final static int JDK1_0 = 10;
    public final static int JDK1_1 = 11;
    public final static int JDK1_2 = 12;
    public final static int JDK1_3 = 13;
    public final static int JDK1_4 = 14;
    public final static int JDK1_5 = 15;
    public final static int JDK1_6 = 16;
    public final static int JDK1_6N = 1610;
    public final static int JDK1_7 = 17;

    private static JVM current;
    static {
        current = new JVM();
    }

    /**
     * @return the current JVM object
     */
    public static JVM current() {
        return current;
    }

    private int jdkVersion;

    /**
     * Creates a new JVM data from the <code>java.version</code>
     * System property
     *  
     */
    public JVM() {
        this(System.getProperty("java.version"));
    }

    /**
     * Constructor for the OS object
     */
    public JVM(String p_JavaVersion) {
        if (p_JavaVersion.startsWith("1.7.")) {
            jdkVersion = JDK1_7;
        } else if (p_JavaVersion.startsWith("1.6.")) {
            for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                if ("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel".equals(info.getClassName())) {
                    jdkVersion = JDK1_6N;
                    break;
                }
            }

            jdkVersion = jdkVersion == 0 ? JDK1_6 : jdkVersion;
        } else if (p_JavaVersion.startsWith("1.5.")) {
            jdkVersion = JDK1_5;
        } else if (p_JavaVersion.startsWith("1.4.")) {
            jdkVersion = JDK1_4;
        } else if (p_JavaVersion.startsWith("1.3.")) {
            jdkVersion = JDK1_3;
        } else if (p_JavaVersion.startsWith("1.2.")) {
            jdkVersion = JDK1_2;
        } else if (p_JavaVersion.startsWith("1.1.")) {
            jdkVersion = JDK1_1;
        } else if (p_JavaVersion.startsWith("1.0.")) {
            jdkVersion = JDK1_0;
        } else {
            // unknown version, assume 1.3
            jdkVersion = JDK1_3;
        }
    }

    public boolean isOrLater(int p_Version) {
        return jdkVersion >= p_Version;
    }

    public boolean isOneDotOne() {
        return jdkVersion == JDK1_1;
    }

    public boolean isOneDotTwo() {
        return jdkVersion == JDK1_2;
    }

    public boolean isOneDotThree() {
        return jdkVersion == JDK1_3;
    }

    public boolean isOneDotFour() {
        return jdkVersion == JDK1_4;
    }

    public boolean isOneDotFive() {
        return jdkVersion == JDK1_5;
    }

    public boolean isOneDotSix() {
        return jdkVersion == JDK1_6;
    }

    /**
     * Determines if the version of JDK1_6 has Nimbus Look and Feel installed.
     * 
     * @return {@code true} if Nimbus is available and the version is 1.6;
     *         {@code false} otherwise
     */
    public boolean isOneDotSixUpdateN() {
        return jdkVersion == JDK1_6N;
    }

    public boolean isOneDotSeven() {
        return jdkVersion == JDK1_7;
    }

}