java线程池_submit()

Posted 2021-06-26 胡乐天

submit()方法

有三个重载方法：

submit（Callable<T> task）//参数为Callable接口的实现类的实例
submit(Runnable task, T result)//第二个参数为默认值
submit(Runnable task)

线程池测试类

package com.thread.pool;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;

public class TestExecuteAndSubmit {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService executors = Executors.newFixedThreadPool(2);
        for (int i=0;i<10;i++){
            FutureTask futureTask = new FutureTask(TestCallable.getInstance());
            Object obj = "默认值";
            executors.submit(futureTask,obj);
            //此处打印futureTask.get(),所以线程会获得线程执行完成任务的结果，才会进入下一层循环
            System.out.println(futureTask.get());
        }
        executors.shutdown();

    }
}

#Callable接口测试类

package com.thread.pool;

import java.util.Date;
import java.util.concurrent.Callable;

public class TestCallable implements Callable {
    private static Callable callable;
    public static synchronized Callable getInstance(){
        if(callable == null){
            callable = new TestCallable();
        }
        return callable;
    }
    @Override
    public Object call() throws Exception {
        for (int i=0;i<10;i++){
            System.out.println((new Date()).toLocaleString() + "   " + Thread.currentThread().getName() + "执行" +i );
        }
        Thread.sleep(2000);
        return "return result";
    }
}