同步程式碼塊（同步監視器）

1. 第一種情況：實現介面Runnable方法

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

        package com.Thread;

        public class Demo012 implements Runnable {
            int ticket = 10;

            @Override
            public void run() {
                int ti = 1;
                for (int people = 100; people > 0; people--) {
                    //做一個實時執行緒監控器；鎖定一個程式碼塊；防止多執行緒爭奪一個資源
                    synchronized (this) {//這個this指呼叫他的物件demo012
                        if (ticket > 0) {
                            System.out.println("我搶到了第" + ticket-- + "張票；從" + Thread.currentThread().getName() + "視窗");
                        }
                    }
                }
            }
        }
 

        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();
            }
        }
 

2. 第二種情況：繼承方法Thread方法

   這裡，我們用到位元組碼檔案來鎖定監視對應的執行緒

        package com.Thread;

        public class TrainTicket extends Thread{
            static int trainticket =10;
            public TrainTicket(String name) {
                super(name);
            }
            public void run() {
                //做一個執行緒同步監視器;this一個程式碼塊有3個物件；這裡TrainTicket的位元組碼唯一性
                synchronized(TrainTicket.class){
                    for(int i = 1;i<=100;i++){//有100人在搶票
                        if(trainticket>0){
                            System.out.println("我搶到了火車票；第"+trainticket--+"張；從"+this.getName()+"視窗");
                        }
                    }
                }
            }
        }
 

        package com.Thread;
        public class Demo001 {
            public static void main(String[] args) {
                TrainTicket trainTicket1 = new TrainTicket("1號");
                trainTicket1.start();
                TrainTicket trainTicket2 = new TrainTicket("2號");
                trainTicket2.start();
                TrainTicket trainTicket3 = new TrainTicket("3號");
                trainTicket3.start();
            }
        }