偶丰富了一下上边提到的例子：

package test034;

import java.util.concurrent.BrokenBarrierException;

import java.util.concurrent.Callable;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

public class ReorderTest {

private int a = 0;

private int b = 0;

public static void main(String[] args) throws InterruptedException,

ExecutionException {

ReorderTest rt = new ReorderTest();

rt.doTest();

}

public void doTest() throws InterruptedException, ExecutionException {

ExecutorService executor = Executors.newFixedThreadPool(2);

//可能出现的结果(关注ThreadATask，ThreadBTask取到的结果)

int num00 = 0; //x=0，y=0

int num10 = 0; //x=1，y=0

int num02 = 0; //x=0，y=2

int num12 = 0; //x=1，y=2

//可能出现的结果(关注主线程取到的结果)

int main00_a = 0;

int main10_a = 0;

int main02_a = 0;

int main12_a = 0;

//可能出现的结果(关注主线程取到的结果)

int main00_b = 0;

int main10_b = 0;

int main02_b = 0;

int main12_b = 0;

int allNum = 100000;

for (int i = 0; i < allNum; i++) {

CountDownLatch latch = new CountDownLatch(1);

Future futureA = executor.submit(new ThreadATask(latch));

Future futureB = executor.submit(new ThreadBTask(latch));

latch.countDown();

if (a==0 && b==0) {main00_a++;}

if (a==1 && b==0) {main10_a++;}

if (a==0 && b==2) {main02_a++;}

if (a==1 && b==2) {main12_a++;}

int x = (Integer) futureB.get(); //取得a

int y = (Integer) futureA.get(); //取得b

if (x==0 && y==0) {num00++;}

if (x==1 && y==0) {num10++;}

if (x==0 && y==2) {num02++;}

if (x==1 && y==2) {num12++;}

if (a==0 && b==0) {main00_b++;}

if (a==1 && b==0) {main10_b++;}

if (a==0 && b==2) {main02_b++;}

if (a==1 && b==2) {main12_b++;}

//重置状态

a = 0;

b = 0;

}

System.out.println("a=0，b=0出现次数：" + main00_a);

System.out.println("a=1，b=0出现次数：" + main10_a);

System.out.println("a=0，b=2出现次数：" + main02_a);

System.out.println("a=1，b=2出现次数：" + main12_a);

System.out.println("");

System.out.println("x=0，y=0出现次数：" + num00);

System.out.println("x=1，y=0出现次数：" + num10);

System.out.println("x=0，y=2出现次数：" + num02);

System.out.println("x=1，y=2出现次数：" + num12);

System.out.println("");

System.out.println("a=0，b=0出现次数：" + main00_b);

System.out.println("a=1，b=0出现次数：" + main10_b);

System.out.println("a=0，b=2出现次数：" + main02_b);

System.out.println("a=1，b=2出现次数：" + main12_b);

executor.shutdown();

}

private class ThreadATask implements Callable {

private CountDownLatch barrier;

public ThreadATask(CountDownLatch barrier) {

this.barrier = barrier;

}

public Integer call() throws InterruptedException,

BrokenBarrierException {

barrier.await(); //

a = 1; // A1

return b; // A2

}

}

private class ThreadBTask implements Callable {

private CountDownLatch barrier;

public ThreadBTask(CountDownLatch barrier) {

this.barrier = barrier;

}

public Integer call() throws InterruptedException,

BrokenBarrierException {

barrier.await();

b = 2; // B1

return a; // B2

}

}

}