Java创建线程的三种方式，同步锁的实现synchronized，lock

Posted 2022-11-22 weixin_ancenhw

一、继承Thread类创建
通过继承Thread并且重写其run()方法，通过调用 start() 方法即可执行线程方法。
写法1：

public class MyThread extends Thread 

    @Override
    public void run() 
        for ( int i = 0;i < 15; i++) 
            System.out.println(getName()+"执行任务线程"+i);
        
    

    public static void main(String[] args) 
        for (int i = 0; i <10 ; i++) 
            new MyThread().start();
        


    

二、 通过Runnable接口创建线程类
该方法需要实现Runnable接口，并重写该接口的 run() 方法

 public static void main(String[] args) 
       new Thread(new MyThread()).start();
        new Thread(new MyThread()).start();
    

    @Override
    public void run() 
        for (int i = 0; i <10 ; i++) 
            System.out.println(Thread.currentThread().getName()+":"+i);
        

    

写法2：

  public static void main(String[] args) 
        MyThread myThread = new MyThread();
        Thread thread = new Thread(myThread);
        thread.start();
        for (int i = 10; i <20 ; i++) 
            System.out.println(Thread.currentThread().getName()+":"+i);
        

    

    @Override
    public void run() 
        for (int i = 0; i < 10; i++) 
            System.out.println(Thread.currentThread().getName()+"执行任务:"+i);
        
    

三、通过创建三个用户抢夺，购票权限，实现同步锁操作，解决超发问题；

public class MyThread implements Runnable 

    private int ticker = 100;

    public static void main(String[] args) 
        MyThread myThread = new MyThread();
        new Thread(myThread).start();
        new Thread(myThread).start();
        new Thread(myThread).start();
    

    @Override
    public void run() 
        while (true) 
            //同步代码块实现同步锁，解决超卖问题
            synchronized (MyThread.class)
                if (ticker > 0) 
                    System.out.println(Thread.currentThread().getName() + "发票:" + ticker);
                    ticker--;
                    try 
                        Thread.sleep(1000);
                     catch (InterruptedException e) 
                        e.printStackTrace();
                    
                
            

        
    

自定义lock锁机制，开始和结束，手动控制

public class LockThread 

    //定义票数
    private static int tikcer = 30;

    //自定义开启锁和关闭锁
    public static void main(String[] args) 
        ReentrantLock lock = new ReentrantLock();
        Runnable runnable = new Runnable() 
            @Override
            public void run() 
                while (true) 
                    //开启锁
                    lock.lock();
                    try 
                        if (tikcer > 0) 
                            System.out.println(Thread.currentThread().getName() + "---剩余票数:" + tikcer);
                            tikcer--;
                        
                     catch (Exception e) 
                       e.printStackTrace();
                     finally 
                        //关闭锁
                        lock.unlock();
                    

                

            
        ;

        new Thread(runnable).start();
        new Thread(runnable).start();
        new Thread(runnable).start();