请问如何获得当前java运行环境的路径?

Question

import java.util.*;
public class Property {
  public static void main(String[] args) {
    System.out.println(new Date());
    Properties p = System.getProperties();   //好像下面根本就没用到属性
    p.list(System.out);                      //下面也没出? p呀？？
    System.out.println("--- Memory Usage:");
    Runtime rt = Runtime.getRuntime();
    System.out.println("Total Memory = "
                       + rt.totalMemory()
                       + " Free Memory = "
                       + rt.freeMemory());  try {
       Thread.currentThread().sleep(5 * 1000);
      } catch(InterruptedException e) {}
}
}