java練習多線程

標籤：pre   class   show   null   封裝   eth   div   bool   code   

1、建立多線程方式繼承Thread類

class ThreadDemo1{    public static void main(String args[]){        Demo1 d1 = new Demo1();        d1.start();        Demo1 d2 = new Demo1();        d2.start();    }}class Demo1 extends Thread{    public void run(){        show();    }    public void show(){        while(true){            try{Thread.sleep(3000);            }catch(InterruptedException e){                            }            System.out.println("ол╣Щ"+Thread.currentThread().getName());        }    }}

2、實現多線程第二種方式Runnable介面

class ThreadDemo2{    public static void main(String[]args){        Demo d1 = new Demo();        Thread t1 = new Thread(d1);        Thread t2 = new Thread(d1);        Thread t3 = new Thread(d1);        Thread t4 = new Thread(d1);        t1.start();        t2.start();        t3.start();        t4.start();    }}class Demo implements Runnable{    private int sum;    public void show(){        for(int x=0;x<20;x++){            synchronized(this){                    sum+=100;                    System.out.println(Thread.currentThread().getName()+"銀行金庫即時金額:"+sum);                }            }    }    public void run(){        show();    }}

3、多線程中的同步代碼塊、同步函數、靜態同步函數需要注意的事項

當函數名用static修飾時，同步鎖不能用this，static函數的鎖使用對象.getClass()擷取的位元組碼檔案或者類名.class擷取；

class ThreadDemo3{    public static void main(String[]args){        Demo d1= new Demo();        Thread t1 = new Thread(d1);        Thread t2 = new Thread(d1);        Thread t3 = new Thread(d1);        Thread t4 = new Thread(d1);        t1.start();        t2.start();        try{Thread.sleep(10);}catch(InterruptedException e){}        Demo.flag=false;        t3.start();        t4.start();    }}/*new Thread(d1);任務封裝後在Thread類裡面的傳遞過程class Thread1 implements Runnable{    Runnable r1;    Thread1(Runnable r1){        this.r1=r1;    }    public void run(){        if(r1!=null)            r1.run();    }    public void start(){        run();    }}*/class Demo implements Runnable{    public static boolean flag=true;    private static int num=300;    public void run(){        if(flag){            while(true)                method();        }else{            synchronized(Demo.class){                while(true)                    if(num>0){                        try{Thread.sleep(30);}catch(InterruptedException e){}                        System.out.println("同步代碼塊售票口："+Thread.currentThread().getName()+"已售出萬達電影院門票號："+num--);                        }            }        }                }    public synchronized static void method(){        if(num>0){                try{Thread.sleep(30);}catch(InterruptedException e){}                System.out.println("同步函數售票口:"+Thread.currentThread().getName()+"已售出萬達電影院門票號："+num--);            }    }}

 

java練習多線程