多线程同步的 例子

方法1、

package RT2;

import java.util.concurrent.locks.ReentrantLock;

public class PersonSync extends Thread{
    
    private final ReentrantLock lock = new ReentrantLock();
    static int j;
    
//    这里是通过synchronized 方法控制多线程 (public synchronized static void quqian(){ )
    public  void quqian(){ // 是对类对象加锁
        synchronized(PersonSync.class){
        for (int i = 0; i < 100; i++) {
            j++;
            System.out.println(Thread.currentThread().getName()+":"+j);
         }
      }
    }
    
//  这里是lock 接口的用法
    public void quloc(){
        lock.lock();  // block until condition holds
         try {
             for (int i = 0; i < 100; i++) {
                j++;
                System.out.println(Thread.currentThread().getName()+":"+j);
             }
         } finally {
           lock.unlock();
         }
    }
    
    public  void run(){
//        quqian();
        quloc();
    }
    
    public static void main(String[] args) {
        
        
        PersonSync p1=new PersonSync();
        p1.start();
        
        PersonSync p2=new PersonSync();
        p2.start();
    }

} 
 
方法2、
 
package RT2;

public class Machine {
    int j=0;
    public  synchronized void quqian(){
        for (int i = 0; i < 100; i++) {
            j++;
            System.out.println(Thread.currentThread().getName()+":"+j);
        }
    }
} 
 
package RT2;

public class Person extends Thread{
    
    public Machine machine;
    
    public Person(Machine machine){
        this.machine=machine;
    }
    
    public  void run(){
        machine.quqian();
    }
    
    public static void main(String[] args) {
        Machine machine=new Machine();
        
        Person p1=new Person(machine);
        p1.start();
        
        Person p2=new Person(machine);
        p2.start();
    }

}