一个类两个接口
Tread类: 使用时继承Thread类
Runnable接口: 使用时实现Runnable接口
Callable接口: 使用时实现Callable接口
由于类只能单继承, 接口可以多继承, 所以尽量使用接口
Thread的继承(创建线程方式一)
/*
* 创建线程方式一:
* 1, 创建: 继承Tread类 + 重写run
* 2, 启动: 创建子类对象 + start
*
*/
public class StartThread extends Thread{
@Override
public void run() {
for(int i = 0; i < 20; i++) {
System.out.println("music");
}
}
public static void main(String[] args) {
// 创建子类对象
StartThread st = new StartThread();
// 启动
st.start(); // 不保证立即运行cpu调用
for(int i = 0; i < 20; i++) {
System.out.println("coding");
}
}
}
Runnable的实现(创建线程方式二)
- 创建目标对象
- 创建线程对象 + 关联目标对象
- 启动线程
/*
* 创建线程方式二:
* 1, 创建: 实现Runnable + 重写run
* 2, 启动: 创建实现类对象 + Thread对象 + start
*
* 推荐: 避免单继承的局限性, 优先使用接口
* 方便共享资源
*/
public class StartRun implements Runnable{
@Override
public void run() {
for(int i = 0; i < 20; i++) {
System.out.println("music");
}
}
public static void main(String[] args) {
/* 方法一: 声明引用
// 创建实现类对象
StartRun sr = new StartRun();
// 创建代理类对象
Thread t = new Thread(sr);
// 启动
t.start(); // 不保证立即运行cpu调用
*/
// 方法二: 匿名(一个对象只使用一次)
new Thread(new StartRun()).start();
for(int i = 0; i < 20; i++) {
System.out.println("coding");
}
}
}
/**********模拟龟兔赛跑示例程序************/
public class Racer implements Runnable {
private static String winner; // 共享资源
@Override
public void run() {
for(int steps = 1; steps <= 100; steps++) {
// 模拟乌龟休息
if(Thread.currentThread().getName().equals("rabbit") && steps%10 == 0) {
try {
Thread.sleep(10);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
System.out.println(Thread.currentThread().getName() + "---->" + steps);
if(gameOver(steps)) {
break;
}
}
}
private boolean gameOver(int steps) {
if(null != winner ) { // 分出胜负后, 通过共享变量结束另一个线程
return true;
} else {
if(steps == 100) {
winner = Thread.currentThread().getName();
System.out.println("winner---->" + winner);
return true;
}
}
return false;
}
public static void main(String[] args) {
Racer racer = new Racer();
new Thread(racer, "tortoise").start();
new Thread(racer, "rabbit").start();
}
}
package cn.zyb.thread;
/**
* 共享资源, 并发
*
* @author Administrator
*
*/
public class Web12306 implements Runnable{
// 票数
private int ticketNumbers = 5;
@Override
public void run() {
while(true) {
if(ticketNumbers < 0) {
break;
}
// 加入睡眠后线程不安全
// try {
// Thread.sleep(100);
// } catch (InterruptedException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
System.out.println(Thread.currentThread().getName()
+ "---->" + ticketNumbers--);
}
}
public static void main(String[] args) {
// 一份资源
Web12306 web = new Web12306();
// 多个代理
new Thread(web, "zyb").start();
new Thread(web, "zpy").start();
new Thread(web, "haha").start();
}
}
/*
zpy---->4
haha---->1
zyb---->2
zpy---->0
*/
Callable的实现(创建线程方式三)
- 创建目标对象
- 创建执行服务
- 提交执行
- 获取结果
- 关闭服务
/****************文件一******************/
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;
public class CDownloader implements Callable<Boolean> {
private String url;
private String name;
public CDownloader(String url, String name) {
this.url = url;
this.name = name;
}
@Override
public Boolean call() throws Exception{
WebDownloader wd = new WebDownloader();
wd.download(url, name);
System.out.println(name);
return true;
}
public static void main(String[] args) throws InterruptedException, ExecutionException {
CDownloader cd1 = new CDownloader("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1538910423159&di=9cad47c1aab60ebb7ab6ff71cfe20646&imgtype=0&src=http%3A%2F%2Fa.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2F377adab44aed2e73c3dc082b8a01a18b87d6fa84.jpg",
"1.jpg");
CDownloader cd2 = new CDownloader("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1538910447240&di=c821bb352f682af7ce07e335f05295c5&imgtype=0&src=http%3A%2F%2Fd.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2F203fb80e7bec54e77d03071cb4389b504ec26ac0.jpg",
"2.jpg");
CDownloader cd3 = new CDownloader("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1538910459543&di=f99f4f6848913e2edc015cc39bf15f79&imgtype=0&src=http%3A%2F%2Fd.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2Fb64543a98226cffc254c32acb4014a90f603ea4e.jpg",
"3.jpg");
// 创建执行服务
ExecutorService ser = Executors.newFixedThreadPool(3);
// 提交执行
Future<Boolean> result1 = ser.submit(cd1);
Future<Boolean> result2 = ser.submit(cd2);
Future<Boolean> result3 = ser.submit(cd3);
// 获取结果
boolean r1 = result1.get();
boolean r2 = result1.get();
boolean r3 = result1.get();
// 关闭服务
ser.shutdownNow();
}
}
/****************文件二******************/
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
// 自定义包
import org.apache.commons.io.FileUtils;
/**
* 下载
* @author Administrator
*
*/
public class WebDownloader {
public void download(String url, String name) {
try {
FileUtils.copyURLToFile(new URL(url), new File (name));
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("不合法URL");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("下载失败");
}
}
}