Milliseconds elapsed since January 1, 1970 : Runtime System « Development « Java Tutorial

1. Java Tutorial
2. Development
3. Runtime System

import java.util.Properties;

public class SystemApp {
  public static void main(String args[]) {
    long time = System.currentTimeMillis();
    System.out.println(time);
    Properties p = System.getProperties();
    p.list(System.out);
    System.exit(13);
  }
}