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JDK1.5 获取线程执行结果 Callable Future

程序员文章站 2022-05-28 18:23:33
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import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

/**
 * Callable  Future  (类是有回调的 线程池任务) 可以获取 线程执行后的 结果(无序的)  
 */
public class CallableAndFuture {
	/**
	 * @param args
	 * @throws ExecutionException 
	 * @throws InterruptedException 
	 */
	public static void main(String[] args) throws InterruptedException,Exception {
		ExecutorService threadPool=Executors.newSingleThreadExecutor();
		
		// 提交当个任务  然后获取等待结果 
		Future<String> future=threadPool.submit(new Callable<String>() {
			@Override
			public String call() throws Exception {
				// TODO Auto-generated method stub
				Thread.sleep(2000);
				return "Hello: "+Thread.currentThread().getName();
			}
		});
		System.out.println("等待结果中...");
		//什么时候有结果后 再获取结果
		System.out.println("结果为:"+future.get());
		
		//等待 1秒后 获取结果  没有取到结果就算了
		System.out.println("结果为:"+future.get(1, TimeUnit.SECONDS));
		threadPool.shutdown();
		
		//批量提交任务  然后 循环获取 执行后的结果 
		ExecutorService threadPool1=Executors.newFixedThreadPool(10);
		CompletionService<Integer> completionService=new ExecutorCompletionService<Integer>(threadPool1);
		for (int i = 0; i < 10; i++) {
			final int seq=i;
			completionService.submit(new Callable<Integer>() {
				@Override
				public Integer call() throws Exception {
					// TODO Auto-generated method stub
					Thread.sleep(new Random().nextInt(5000));
					return seq;
				}
				
			});
		}
		System.out.println("2等待结果中...");
		for (int i = 0; i < 10; i++) {
			System.out.println(completionService.take().get());
		}
		
		threadPool1.shutdown();
		
	}

}