多线程 FutureTask、Future、Callable

1、Future

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

@Slf4j
public class FutureExample {

    static class MyCallable implements Callable<String> {

        @Override
        public String call() throws Exception {
            log.info("do something in callable");
            Thread.sleep(5000);
            return "Done";
        }
    }

    public static void main(String[] args) throws Exception {
        ExecutorService executorService = Executors.newCachedThreadPool();
        Future<String> future = executorService.submit(new MyCallable());
        log.info("do something in main");
        Thread.sleep(1000);
        String result = future.get();
        log.info("result：{}", result);
        executorService.shutdown();
    }
}

2、FutureTask

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;

@Slf4j
public class FutureTaskExample {

    public static void main(String[] args) throws Exception {
        FutureTask<String> futureTask = new FutureTask<String>(new Callable<String>() {
            @Override
            public String call() throws Exception {
                log.info("do something in callable");
                Thread.sleep(5000);
                return "Done";
            }
        });

        new Thread(futureTask).start();
        log.info("do something in main");
        Thread.sleep(1000);
        String result = futureTask.get();
        log.info("result：{}", result);
    }
}

3、ThreadPoolExecutor

import java.util.concurrent.*;

public class ThreadPoolExecutorTest {

    public static void main(String[] args) throws Exception {
        ArrayBlockingQueue<Runnable> queue = new ArrayBlockingQueue<Runnable>(1000);
        ThreadPoolExecutor poolExecutor = new ThreadPoolExecutor(
                5,
                5,
                1000,
                TimeUnit.SECONDS,
                queue);

        Future<String> future = poolExecutor.submit(new Callable<String>() {
            @Override
            public String call() throws Exception {
                TimeUnit.SECONDS.sleep(5);
                return "hello";
            }
        });
        String result = future.get();
        System.out.println(result);
        poolExecutor.shutdown();
    }

}

来源：oschina

链接：https://my.oschina.net/u/3777515/blog/3214949

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