Java线程：在随机时间启动和休眠线程

Question

i am trying to make a server-client Socket program (TCP) in java. In my client program, i have created 10 threads, these 10 threads will act as a separate client and when it runs it connnects to socket at server side.

Now, I want that the threads should start at random time then go to sleep at random time and then again resume from their sleep state. this randomization is because i am running client and server program on localhost, so i want that threads should behave as there are many users who access a single server(like we have google) at any instant of time.

I am not any solution for this... plz help me and suggest something which i can try.

I have tried Timer and TimerTask class... but it is not fulfilling my need.. Timer class perform its assigned tasks in a sequence.. not in random manner..

so is there any solution instead of Timer and TimerTask .

Answer 1

You can use a scheduled executor with fixed thread pool size, that sleeps at random time and initially starts at random time:

import java.util.Random;
import java.util.concurrent.*;

public class Client{
    private final static ScheduledExecutorService executor = Executors.newScheduledThreadPool(10);

    public static void main(String[] args) {
        final Random random = new Random();
        final long maxSleepTime=2000L;
        for (int i = 0; i < 10; i++) {
            int randomSleepTime = random.nextInt((int) maxSleepTime);
            Runnable command=new Runnable() {
                @Override public void run() {
                    //code to run, e.g. call a server method
                }
            };
            executor.scheduleAtFixedRate(command,randomSleepTime,randomSleepTime, TimeUnit.MILLISECONDS);
        }
    }
}

Answer 2

this example use an executor with 10 threads... the idea is to submit your tasks and the executor will handle the threads for you.

public class Test {


private final Executor executor= Executors.newFixedThreadPool(10);

public void executeTask(Runnable task){
    executor.execute(task);
}


public static void main(String[] args) {
    Test test= new Test();
    for(int i=0;i<100;i++){

        final int iteration=i;
        Runnable task=(new Runnable() { public void run() {System.out.println("Executing task "+iteration); }});
        test.executeTask(task);
    }
}

}

Answer 3

A very straight forward solution could look like this:

Call Thread.sleep(sleepTime); whereas sleepTime is generated randomly.

import java.util.Random;

public class Client extends Thread
{
    boolean run = true;

    public void run() {

        Random rnd = new Random();

        try {

            while(run == true) {

                // ..
                // Do whatever a client does ..
                // ..

                Integer sleepTime = rnd.nextInt(100);

                Thread.sleep(sleepTime);

                System.out.println("Slept for " + sleep + "ms");

                // Replace this by an appropriate condition
                if(sleep > 50) {
                    System.out.println("I'm out ..");
                    run = false;
                }
            }

        } catch(InterruptedException v) {
            System.out.println(v);
        }
    } 
}

public class Main{

     public static void main(String []args){         
        Client client = new Client();            
        client.run();
     }
}