How to use Hyperic SIGAR API with APPLET to detect Client OS version and architecture

Question

How to use Hyperic SIGAR API with APPLET to detect Client OS version and architecture.

Actually I need to detect client machine's OS verion & architecture using APPLET. I planned to use SIGAR. But sigar.jar needs some dlls to detect the information, which is stopping me from using it to detect client system's OS information. Please help.

Answer 1

You don't need any special API if your applet is signed. You can use Java built in libraries.

To get system information you can read java system variables os.version, os.arch and os.name.

Here is the code, which you can start with to find those variables:

package com.ic.utils;

import java.util.Arrays;
import java.util.Comparator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Set;

/**
 * Prints different system variables
 * @author MockerTim
 */
public class EnvFinder {
    /**
     * Prints environment variables
     */
    public void listSystemEnv() {
        System.out.println("\nSystem Environment Variables:\n");
        Map<String,String> map = System.getenv();
        Set<Entry<String,String>> entrys = map.entrySet();

        Entry<String,String>[] a = sortSystemEnv(entrys);
        for (int i = 0; i < a.length; i++) {
            Entry<String, String> entry = a[i];
            System.out.println(entry.getKey() + " : " + entry.getValue());
        }
    }

    private Entry<String,String>[] sortSystemEnv(Set<Entry<String,String>> set) {
        Entry<String,String>[] a = new Entry[set.size()];
        set.toArray(a);

        Arrays.sort(a, new Comparator<Entry<String,String>>() {

            @Override
            public int compare(Entry<String, String> o1, Entry<String, String> o2) {
                return o1.getKey().compareToIgnoreCase(o2.getKey());
            }
        });

        return a;
    }

    /**
     * Prints java system properties
     */
    public void listJavaSystemProperties() {
        System.out.println("\nJava System Properties:\n");
        Properties sysProp = System.getProperties();

        Set<String> keys = sysProp.stringPropertyNames();
        Pair<String,String>[] pairs = new Pair[keys.size()];
        int i = 0;
        for (String string : keys) {
            pairs[i++] = new Pair<String,String>(string, sysProp.getProperty(string));
        }

        Arrays.sort(pairs, new Comparator<Pair<String,String>> () {

            @Override
            public int compare(Pair<String, String> o1, Pair<String, String> o2) {
                return o1.getFirst().compareToIgnoreCase(o2.getFirst());
            }
        });

        for (int j = 0; j < pairs.length; j++) {
            Pair<String, String> pair = pairs[j];
            System.out.println(pair.getFirst() + " : " + pair.getSecond());
        }
    }

    public static void main(String[] args) {
        EnvFinder instance = new EnvFinder();
        instance.listJavaSystemProperties();
        instance.listSystemEnv();
    }
}

/**
 * Support class for EnvFinder.class
 * @author tss
 * @param <T0>
 * @param <T1>
 */
class Pair<T0, T1> {

    public Pair (T0 t0, T1 t1) {
        first = t0;
        second = t1;
    }

    public T0 getFirst() {
        return first;
    }

    public T1 getSecond() {
        return second;
    }

    private T0 first;
    private T1 second;
}

Update:

See how-to-make-a-jar-file-that-include-dll-files and calling-a-dll-from-an-applet-via-jni. That should help you.