package cn.itcast.heima2;
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;
//返回线程执行完后的结果
public class CallableAndFuture {
/**
* @param args
*/
public static void main(String[] args) {
ExecutorService threadPool = Executors.newSingleThreadExecutor();
//Future<T> 返回的结果
Future<String> future =
threadPool.submit(
new Callable<String>() { //需要执行的任务
public String call() throws Exception {
Thread.sleep(2000);
return "hello";
};
}
);
System.out.println("等待结果");
try {
System.out.println("拿到结果：" + future.get()); //拿到返回结果需要等待
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ExecutorService threadPool2 = Executors.newFixedThreadPool(10);
//提交一组任务
CompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(threadPool2);
for(int i=1;i<=10;i++){
final int seq = i;
completionService.submit(new Callable<Integer>() {
@Override
public Integer call() throws Exception {
Thread.sleep(new Random().nextInt(5000));
return seq;
}
});
}
for(int i=0;i<10;i++){
try {
//获取每个任务的返回值
System.out.println(
completionService.take().get());
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}