source: main/trunk/search4j/DisplayJavaVersion.java@ 36214

class DisplayJavaVersion
{
    public static void main(String args[])
    {  
    boolean verbose = false;

    if (args.length == 1) {
        String arg0 = args[0];

        if (arg0.equals("-v") || arg0.equals("-verbose") || arg0.equals("--verbose")) {
        verbose = true;
        }
    }

    // Adapted from:
    //  https://stackoverflow.com/questions/2591083/getting-java-version-at-runtime
    
    String era, major, minor, update, build;

    // 'java.version' property returns:
    //    era.major.minor
    // 'java.runtime.version' returns:
    //    era.major.minor_update-build

    // The simpler case can be deal with using:
    //   String[] javaVersionElements = System.getProperty("java.version").split("\\.");
    //
    // However, as search4j.cpp has already been written assuming that version information
    // includes update (but not build number) details, then do the following:
    //
    String[] javaVersionElements = System.getProperty("java.runtime.version").split("\\.|_|-b");

    era     = javaVersionElements[0];
    major   = javaVersionElements[1];
    minor   = javaVersionElements[2];
    update  = javaVersionElements[3];
    build   = javaVersionElements[4]; // (unused)


    // Testing bitness of JVM
    //   https://www.baeldung.com/java-detect-jvm-64-or-32-bit  
    //boolean is_64bit = com.sun.jna.Platform.is64Bit();

    String version_str = era+"."+major+"."+minor+"_"+update;
    
    if (verbose) {
        System.out.println("Version: " + version_str);
    }
    else {
        System.out.println(version_str);
    }
    }
}