java获取异步线程执行结果示例，也是Executors框架的基本原理

人狠话不多，直接上代码，代码拷贝到本地直接运行，自己研究吧。

public interface MyFuture<V> {
    V get() throws Exception;
}

 

public interface Callback<v> {
    v call() throws Exception;
}

public class ExecuteThread<V> extends Thread {
    private V result=null;
    private Exception exception=null;
    private boolean done=false;
    private Callback<V> task;
    private Object lock;

    public ExecuteThread(Callback<V> task, Object lock) {
        this.task = task;
        this.lock = lock;
    }

    @Override
    public void run() {
        try {
            result=task.call();
        } catch (Exception e) {
            //e.printStackTrace();
            exception=e;
        }finally {
            synchronized (lock){
                done=true;
                lock.notifyAll();
            }
        }
    }

    public V getResult() {
        return result;
    }


    public Exception getException() {
        return exception;
    }


    public boolean isDone() {
        return done;
    }

}

 

 

public class MyExecutor<V> {

    public <V> MyFuture<V> execute(final Callback<V> task){
        final Object lock=new Object();
        final ExecuteThread<V> thread=new ExecuteThread<>(task,lock);
        thread.start();

        MyFuture<V> future=new MyFuture<V>() {
            @Override
            public V get() throws Exception {
                synchronized (lock){
                    while (!thread.isDone()){
                        lock.wait();
                    }
                }
                if(thread.getException()!=null){
                    throw thread.getException();
                }
                return thread.getResult();
            }
        };
        return future;
    }
}

 

 主线程代码：

import java.util.Random;

public class Main {
    public static void main(String[] args) throws Exception {
        MyExecutor executor=new MyExecutor();
        Callback<Integer> subTask=new Callback<Integer>() {
            @Override
            public Integer call() throws Exception {
                Random rdm=new Random();
                int millis=rdm.nextInt(1000);
                Thread.sleep(millis);
                return millis;
            }
        };

        MyFuture<Integer> future=executor.execute(subTask);
        Integer result=future.get();
        System.out.println(result);
    }
}

 

代码枯燥难懂，但是我有什么办法呢？

只能自己慢慢研究了。