JVM.java

/*
 * @(#)JVM.java
 *
 * $Date: 2011-05-02 16:01:45 -0500 (Mon, 02 May 2011) $
 *
 * Copyright (c) 2011 by Jeremy Wood.
 * All rights reserved.
 *
 * The copyright of this software is owned by Jeremy Wood.
 * You may not use, copy or modify this software, except in
 * accordance with the license agreement you entered into with
 * Jeremy Wood. For details see accompanying license terms.
 * 
 * This software is probably, but not necessarily, discussed here:
 * http://javagraphics.java.net/
 * 
 * That site should also contain the most recent official version
 * of this software.  (See the SVN repository for more details.)
 */
package ale.util.colors.bric.util;

import java.security.AccessControlException;

/**
 * Static methods relating to the JVM environment.
 * <P>
 * Instead of burying a constant like "isQuartz" in its most relevant class (such as OptimizedGraphics2D), it should be
 * stored here so if other classes need to access it they don't necessary have to
 */
public class JVM {

    /**
     * Prints basic information about this session's JVM: the OS name & version, the Java version, and (on Mac) whether
     * Quartz is being used.
     */
    public static void printProfile() {
        System.out.println(getProfile());
    }

    /**
     * Gets basic information about this session's JVM: the OS name & version, the Java version, and (on Mac) whether
     * Quartz is being used.
     */
    public static String getProfile() {
        StringBuffer sb = new StringBuffer();
        sb.append("OS = " + System.getProperty("os.name") + " (" + System.getProperty("os.version") + "), " + System.getProperty("os.arch")
                + "\n");
        sb.append("Java Version = " + System.getProperty("java.version") + "\n");
        if (JVM.isMac) {
            sb.append("apple.awt.graphics.UseQuartz = " + usingQuartz);
        }
        return sb.toString();
    }

    /**
     * The major Java version being used (1.4, 1.5, 1.6, etc.), or -1 if this value couldn't be correctly determined.
     */
    public static final float javaVersion = JVM.getMajorJavaVersion(true);

    private static final String osName = (System.getProperty("os.name").toLowerCase());

    /** Whether this session is on a Mac. */
    public static final boolean isMac = (osName.indexOf("mac") != -1);

    /** Whether this session is on Windows. */
    public static final boolean isWindows = (osName.indexOf("windows") != -1);

    /** Whether this session is on Vista. */
    public static final boolean isVista = (osName.indexOf("vista") != -1);

    /** Whether this session is on Windows 7. */
    public static final boolean isWindows7 = isWindows && (osName.indexOf("7") != -1);

    /** Whether this session is on Windows XP. */
    public static final boolean isWindowsXP = isWindows && (osName.indexOf("xp") != -1);

    /** Whether this session is on Windows Vista or Windows 7. */
    public static final boolean isVistaOrWindows7 = isVista || isWindows7;

    /** If on a Mac: whether Quartz is the rendering pipeline. */
    public static final boolean usingQuartz = isMac
            && (((javaVersion > 0) && (javaVersion < 1.4f)) ||
                    ((System.getProperty("apple.awt.graphics.UseQuartz") != null) && System.getProperty("apple.awt.graphics.UseQuartz").toString()
                            .equals("true")));

    /**
     * This converts the system property "java.version" to a float value. This drops rightmost digits until a legitimate
     * float can be parsed. <BR>
     * For example, this converts "1.6.0_05" to "1.6". <BR>
     * This value is cached as the system property "java.major.version". Although technically this value is a String, it
     * will always be parseable as a float.
     * 
     * @throws AccessControlException
     *             this may be thrown in unsigned applets! Beware!
     */
    public static float getMajorJavaVersion() throws AccessControlException {
        String majorVersion = System.getProperty("java.major.version");
        if (majorVersion == null) {
            String s = System.getProperty("java.version");
            float f = -1;
            int i = s.length();
            while ((f < 0) && (i > 0)) {
                try {
                    f = Float.parseFloat(s.substring(0, i));
                } catch (Exception e) {
                }
                i--;
            }
            majorVersion = Float.toString(f);
            System.setProperty("java.major.version", majorVersion);
        }
        return Float.parseFloat(majorVersion);
    }

    /**
     * 
     * @param catchSecurityException
     *            if true and an exception occurs, then -1 is returned.
     * @return the major java version, or -1 if this can't be determined/
     */
    public static float getMajorJavaVersion(boolean catchSecurityException) {
        try {
            return getMajorJavaVersion();
        } catch (RuntimeException t) {
            if (catchSecurityException) {
                System.err.println("this exception was ignored without incident, but it means we can't determine the major java version:");
                t.printStackTrace();
                return -1;
            }
            throw t;
        }
    }
}