详解Java中异步转同步的六种方法

private static long MILLIS_OF_WAIT_TIME = 300000L;// 等待时间 5分钟
private final Object lock = new Object();

//3.结果返回后进行回调，解除阻塞
@Override
public void callback(AsynResponse response){
    synchronized(lock){
        //设置状态条件
}
 
public Result getResult() throws ErrorCodeException {
// 1.异步调用
 
// 2.阻塞等待异步响应
    long future = System.currentTimeMillis() + MILLIS_OF_WAIT_TIME;
    long remaining = MILLIS_OF_WAIT_TIME;//剩余等待时间
    while(remaining > 0){
        synchronized(lock){
            if(状态条件未满足){
                remaining = future - System.currentTimeMillis();
                Thread.sleep(时间具体场景确定)；
            }
        }  
````}
 
//4.超时或结果正确返回，对结果进行处理
     
    return result;
}

private static long MILLIS_OF_WAIT_TIME = 300000L;// 等待时间 5分钟
private final Object lock = new Object();

//3.结果返回后进行回调，解除阻塞
@Override
public void callback(AsynResponse response){
    synchronized(lock){
        lock.notifyAll();
}
 
public Result getResult() throws ErrorCodeException {
	// 1.异步调用
 
	// 2.阻塞等待异步响应
    long future = System.currentTimeMillis() + MILLIS_OF_WAIT_TIME;
    long remaining = MILLIS_OF_WAIT_TIME;//剩余等待时间
    synchronized(lock){
        while(条件未满足  && remaining > 0){ //被通知后要检查条件
            lock.wait(remaining);
            remaining = future - System.currentTimeMillis();
        }  
````}
    
	//4.超时或结果正确返回，对结果进行处理
    return result;
}

private static long SECONDS_OF_WAIT_TIME = 300L;// 等待时间 5分钟
private final Lock lock = new ReentrantLock();
private final Condition condition = lock.newCondition();

//3.结果返回后进行回调，解除阻塞
@Override
public void callback(AsynResponse response){
    lock.lock();//这是前提
    try {
        condition.signal();
    }finally {
        lock.unlock();
    }
}

public Result getResult() throws ErrorCodeException {
	// 1.异步调用
	// 2.阻塞等待异步响应
    lock.lock();//这是前提
    try {
        condition.await();
    } catch (InterruptedException e) {
        //TODO
    }finally {
        lock.unlock();
    }
	//4.超时或结果正确返回，对结果进行处理
    return result;
}

private static long SECONDS_OF_WAIT_TIME = 300L;// 等待时间 5分钟
private final CountDownLatch countDownLatch = new CountDownLatch(1);

//3.结果返回后进行回调，解除阻塞
@Override
public void callback(AsynResponse response){
    countDownLatch.countDown();
}

public Result getResult() throws ErrorCodeException {
    // 1.异步调用

    // 2.阻塞等待异步响应
    try {
        countDownLatch.await(SECONDS_OF_WAIT_TIME, TimeUnit.SECONDS);
    } catch (InterruptedException e) {
        //TODO
    }
	//4.超时或结果正确返回，对结果进行处理
    return result;
}

private static long SECONDS_OF_WAIT_TIME = 300L;// 等待时间 5分钟
private final CountDownLatch cyclicBarrier= new CyclicBarrier(2);//设置屏障拦截的线程数为2

//3.结果返回后进行回调，解除阻塞
@Override
public void callback(AsynResponse response){
    //我也到达屏障了，可以开门了
    cyclicBarrier.await();
}

public Result getResult() throws ErrorCodeException {
    // 1.异步调用
    // 2.阻塞等待异步响应
    try {
        //我到达屏障了，还没开门，要等一等
        cyclicBarrier.await(SECONDS_OF_WAIT_TIME, TimeUnit.SECONDS);
    } catch (InterruptedException e) {
        //TODO
    }
	//4.超时或结果正确返回，对结果进行处理
    return result;
}

private static long NANOS_OF_WAIT_TIME = 300000000L;// 等待时间 5分钟
private final LockSupport lockSupport = new LockSupport();

//3.结果返回后进行回调，解除阻塞
@Override
public void callback(AsynResponse response){
    lockSupport.unpark();
}

public Result getResult() throws ErrorCodeException {
    // 1.异步调用

    // 2.阻塞等待异步响应
    try {
        lockSupport.parkNanos(NANOS_OF_WAIT_TIME);
    } catch (InterruptedException e) {
        //TODO
    }
	//4.超时或结果正确返回，对结果进行处理
    return result;

}