Displaying System details in Java

import java.util.Map;
import java.util.Set;
import java.util.Iterator;

public class EnvironmentInformation{
    public static void main(String[] args){
        Map map = System.getenv();
        Set keys = map.keySet();
        Iterator iterator = keys.iterator();
        System.out.println("Variable Name \t Variable Values");
        while (iterator.hasNext()){
            String key = (String) iterator.next();
            String value = (String) map.get(key);
            System.out.println(key + "     " + value);
            }
    }
}