多线程（2）

简单的多线程理解，一个简单的购票，创建4个线程，卖5张票.

package util;


public class Test{

public static void main(String[] args) {
new Test().new Ticket().start();
new Test().new Ticket().start();
new Test().new Ticket().start();
new Test().new Ticket().start();

}

class Ticket extends Thread{

private int tick = 5;


public void run() {
while(true){
if(tick > 0){
System.out.println(Thread.currentThread().getName()+"----"+ tick--);
}
}

}

}

}

打印结果：

Thread-0----5
Thread-1----5
Thread-2----5
Thread-1----4
Thread-0----4
Thread-0----3
Thread-3----5
Thread-3----4
Thread-3----3
Thread-3----2
Thread-3----1
Thread-1----3
Thread-2----4
Thread-2----3
Thread-2----2
Thread-2----1
Thread-1----2
Thread-1----1
Thread-0----2
Thread-0----1

发现每个线程都有5张票卖出，与现实不符，发现在内部类的是，变量tick没有定义静态，修改完之后，

package util;


public class Test{

private static int tick = 5;

public static void main(String[] args) {
new Test().new Ticket().start();
new Test().new Ticket().start();
new Test().new Ticket().start();
new Test().new Ticket().start();

}

class Ticket extends Thread{

public void run() {
while(true){
if(tick > 0){
System.out.println(Thread.currentThread().getName()+"----"+ tick--);
}
}

}

}


}

打印结果：

Thread-0----5
Thread-1----4
Thread-0----3
Thread-2----1
Thread-1----2

一般程勋中不推荐用静态变量，回收时间比较长.

推荐写法：

package util;


public class Test{



public static void main(String[] args) {
Ticket t= new Test().new Ticket();
Thread t1 = new Thread(t);
Thread t2 = new Thread(t);
Thread t3 = new Thread(t);
Thread t4 = new Thread(t);
t1.start();
t2.start();
t3.start();
t4.start();

}

class Ticket implements Runnable{
private  int tick = 5;
public void run() {
while(true){
if(tick > 0){
System.out.println(Thread.currentThread().getName()+"----"+ tick--);
}
}

}

}


}

打印结果：

Thread-0----5
Thread-2----3
Thread-2----1
Thread-1----4
Thread-0----2