方法一：继承Thread

Thread

package com.bjsxt.create;/*** @author dell* @data 2021/3/2* 创建一个线程对象，并启动线程**    注意：启动main方法，自动创建main线程*    *      thread.join() 阻塞乌龟线程，乌龟执行完，兔子才有机会*      *    Thread类的常用方法：*     public void run()*     thread.start();*     this.getName()*     this.getPriority()*     thread.setNam()*     Thread.currentThread().getPriority()**/
public class TextThread {public static void main(String[] args) throws InterruptedException {//启动乌龟线程Thread thread = new TortoiseThread();thread.setName("乌龟1线程");thread.start();  //启动一个新的线程thread.join(); //阻塞乌龟1线程，其他执行完，乌龟1才有机会Thread thread2 = new TortoiseThread();thread2.setName("乌龟2线程");thread2.start();  //启动一个新的线程//兔子也在跑Thread.currentThread().setName("主线程");while (true){System.out.println("兔子领先了" + Thread.currentThread().getName() + " " +Thread.currentThread().getPriority());}}
}

main

package com.bjsxt.create;/*** @author dell* @data 2021/3/2* 定义一个乌龟线程类*/
public class TortoiseThread extends Thread{/*** 线程体：线程要执行的任务*/@Overridepublic void run() {while(true){System.out.println("乌龟领先" +this.getName()+ " "+this.getPriority());}}}

方法二：实现Runnable

Runnable

package com.bjsxt.create2;/*** @author dell* @data 2021/3/2*      定义线程方式2：  实现Runnable接口*      创建线程对象：先定义一个任务，Runnable runnable = new TortoiseRunnable();*                 再创建一个线程，Thread thread1 = new Thread(runnable);**    •两种方式的优缺点*    方式1：继承Thread类*    缺点：Java单继承，无法继承其他类*    优点：代码稍微简单*    方式2：实现Runnable接口*    优点  还可以去继承其他类 便于多个线程共享同一个资源*    缺点：代码略有繁琐*    实际开发中，方式2使用更多一些**/
public class TortoiseRunnable implements Runnable {@Overridepublic void run() {while (true){System.out.println("乌龟领先了" + Thread.currentThread().getName() + " " +Thread.currentThread().getPriority());}}
}

main

package com.bjsxt.create2;/*** @author dell* @data 2021/3/2*/
public class TextThread {public static void main(String[] args) {//两个乌龟在跑Runnable runnable = new TortoiseRunnable();Thread thread1 = new Thread(runnable);thread1.setName("乌龟1线程");thread1.setPriority(Thread.MAX_PRIORITY);thread1.start();//Runnable runnable1 = new TortoiseRunnable();Thread thread2 = new Thread(runnable,"乌龟2线程");thread2.start();//一个兔子在跑Thread.currentThread().setName("主线程");while (true){System.out.println("兔子领先了" + Thread.currentThread().getName() + " " +Thread.currentThread().getPriority());}}
}

优化：使用匿名内部类来创建线程对象

package com.bjsxt.create2;/*** @author dell* @data 2021/3/2* •可以使用匿名内部类来创建线程对象*/
public class TextThread2 {public static void main(String[] args) {//两个乌龟在跑Runnable runnable = new Runnable(){@Overridepublic void run() {while (true){System.out.println("乌龟领先了" + Thread.currentThread().getName() + " " +Thread.currentThread().getPriority());}}};Thread thread1 = new Thread(runnable);thread1.setName("乌龟1线程");thread1.setPriority(Thread.MAX_PRIORITY);thread1.start();Runnable runnable1 = new TortoiseRunnable();Thread thread2 = new Thread(runnable,"乌龟2线程");thread2.start();//一个兔子在跑Thread.currentThread().setName("主线程");while (true){System.out.println("兔子领先了" + Thread.currentThread().getName() + " " +Thread.currentThread().getPriority());}}
}

方法三：继承Callable接口

优点：有返回值，可以抛出异常

package com.bjsxt.create3;import java.util.Random;
import java.util.concurrent.*;/*** @author dell         CTRL+z 返回上一步* @data 2021/3/2      有返回值，可以抛出异常*/
public class RandomCallable implements Callable <Integer> {@Overridepublic Integer call() throws Exception {Thread.sleep(6000);return new Random().nextInt(10);}public static void main(String[] args) throws ExecutionException, InterruptedException {//创建一个线程对象Callable<Integer> callable = new RandomCallable();FutureTask<Integer> task = new FutureTask(callable);Thread thread = new Thread(task);//启动线程thread.start();//获取返回值System.out.println(task.isDone());int result= task.get();                //得不到返回值就一直等待/*int result= 0;try {result = task.get(3, TimeUnit.SECONDS);} catch (TimeoutException e) {e.printStackTrace();}*/System.out.println(task.isDone());System.out.println(result);}
}