创建线程的三种方式
一、继承Thread类
java中类是单继承的,继承了该类就无法继承其他类,增加了代码的耦合度,现在提倡的是面向接口编程。
二、实现Runnable接口
相比与方式一,使用实现接口来实现,降低了程序间的耦合度,缺点是没有返回值。
三、实现Callable接口,将Callable实例传给FutureTask(FutureTask实现了RunnableFuture接口,RunnableFuture继承了Runnable接口)
和方式二一样也是通过实现接口来创建线程,不同的是可以有返回值。
代码:
package com.shamgod.thread; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import java.util.concurrent.FutureTask; /** * 创建线程的三种方式 * @author ShammGod * */ public class TestThread { public static void main(String[] args) throws InterruptedException, ExecutionException { //继承Thread类 Thread t1 = new Thread1(); t1.start(); //实现Runnable接口,将该实例作为参数创建Thread对象 Runnable runnable = new Thread2(); Thread t2 = new Thread(runnable); t2.start(); //实现Callable接口,将该实例作为参数创建FutureTask对象,将FutureTask对象作为参数创建Thread对象 Callable callable = new Thread3(); FutureTask<String> futureTask = new FutureTask<>(callable); Thread t3 = new Thread(futureTask); t3.start(); futureTask.get();//call方法的返回值 //实现Callable接口,将该实例传给线程池的submit方法启动线程 ExecutorService threadPool = Executors.newCachedThreadPool(); Callable<String> task = new Thread3(); Future<String> future = threadPool.submit(task); threadPool.shutdown(); future.get();//call方法的返回值 } } /** * 1、继承Thread * @author ShammGod * */ class Thread1 extends Thread{ @Override public void run() { System.out.println("我是继承Thread创建的线程:" + Thread.currentThread().getName()); } } /** * 2、实现Runnable接口 * @author ShammGod * */ class Thread2 implements Runnable{ @Override public void run() { // TODO Auto-generated method stub System.out.println("我是实现Runnable接口创建的线程:"+Thread.currentThread().getName()); } } /** * 3、实现Callable接口 * @author ShammGod * */ class Thread3 implements Callable<String>{ @Override public String call() throws Exception { System.out.println("我是实现Callable接口创建的线程:"+Thread.currentThread().getName()); return "返回值"; } }
若有不正之处请多多谅解,并欢迎批评指正。