java - Set off a scheduled event at a given time? -

i'm writing java-based shell-type... erm.. thing. anyway, 1 of commands implementing schedule command, can tell time want run command , waits time, runs command once, , exits. however, can't figure out how check time - implemented 1 checks if dates equal, did little research see if better solution existed, found apparently date not thing use. should do?

mcve:

import java.util.date;  public class scheduler extends thread {     private date goat;     private string command;     public scheduler(date goat, string command) {         this.goat = goat;         this.command = command;     }     public void start() {         super.start();     }     public void run() {         while (!goat.equals(new date())) {} //wait until dates equal         runcommand(command); //in real thing, runs command.     }     public void runcommand(string command) {         system.out.println("command: " + command);     }     public static void main(string[] args) {         scheduler task = new scheduler(new date(system.currenttimemillis() + 5000));         task.start();     } } 

i done without using third-party libraries, or libraries must downloaded separately. if there no way so, accept answers third-party library, preference goes solutions without them. ideal if answers allowed me directly specify time run command, rather calculating relative time difference , using that.

one option use timers/timertasks schedule commands - here tutorial.

another option put commands in delayqueue (with delay set time task should fire), use consumer thread repeatedly call take on queue , fire commands removes.

in terms of third party libraries, quartz scheduler.