lock鎖（JDK1.5後新增）

1. 鎖的優先使用級

   lock>程式碼鎖>方法鎖

   程式碼塊鎖synchronized的this指的是同一個demo012；

        package com.Thread;

        import java.util.concurrent.locks.Lock;
        import java.util.concurrent.locks.ReentrantLock;

        public class TrainTicket extends Thread{
            static int trainticket =10;
            public TrainTicket(String name) {
                super(name);
            }
            //lock是一個介面；必須呼叫他的實現類
            Lock lock = new ReentrantLock();
            public void run() {
                //把鎖關上
                lock.lock();
                //有100人在搶票
                for(int i = 1;i<=100;i++){
                    if(trainticket>0){
                        System.out.println("我搶到了火車票；第"+trainticket--+"張；從"+this.getName()+"視窗");
                    }
                }
                //把鎖開啟
                lock.unlock();
            }
        }

 

        package com.Thread;
        public class Demo011 {
            public static void main(String[] args) {
                Demo012 demo012 = new Demo012();
                Thread thread = new Thread(demo012,"1號");
                thread.start();
                Thread thread2 = new Thread(demo012,"2號");
                thread2.start();
                Thread thread3 = new Thread(demo012,"3號");
                thread3.start();
            }
        }