Fork/join

package com.example.test.thread;

import java.util.HashMap;
import java.util.concurrent.*;

public class TestHashMap {

public static void main(String[] args) throws ExecutionException, InterruptedException {
    long start = System.currentTimeMillis();
    ForkJoinPool forkJoinPool = (ForkJoinPool)Executors.newWorkStealingPool();
    ThreadTest threadTest = new ThreadTest(10,"00000000",0,10);
    forkJoinPool.submit(threadTest);
    System.out.println(threadTest.get());
    System.out.println((System.currentTimeMillis()-start)/1000);
}

}

class ThreadTest extends RecursiveTask{

private int count;

private String soutStr;

private int start;

private int end;

public ThreadTest(int count, String soutStr, int start, int end) {
    this.count = count;
    this.soutStr = soutStr;
    this.start = start;
    this.end = end;
}

@Override
protected String compute() {
    int devi = start -end;
    if(devi==0){
        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return soutStr;
    }else{
        int endTemp = (start+end)/2;
        ThreadTest res = new ThreadTest(count, "222222222", start, start - endTemp);
        res.fork();
        ThreadTest res2 = new ThreadTest(count, "22222222222222", devi+1, end);
        res2.fork();
        String rs = res.join();
        String rs2 = res.join();
        return rs+rs2;
    }
}

}