Example of ticket selling with reentrant lock

1.synchronized

package juc.one;

class Ticket {
    // Number of votes 
    private int number = 30;
    // Operation method ： Selling tickets 
    public synchronized void sale() {
        // Judge ： Do you have a ticket? 
        if(number > 0){
            System.out.println(Thread.currentThread().getName()+" ： sell ："+(number--)+"  be left over ："+number);
        }
    }
}

public class SaleTicket {
    // The second step   Create multiple threads , Call the operation method of the resource class 
    public static void main(String[] args) {
        // establish Ticket object 
        Ticket ticket = new Ticket();
        // Create three threads 
        new Thread(new Runnable() {
            @Override
            public void run() {
                // Call ticket selling method 
                for(int i=0;i<40;i++){
                    ticket.sale();
                }
            }
        },"AA").start();

        new Thread(new Runnable() {
            @Override
            public void run() {
                // Call ticket selling method 
                for(int i=0;i<40;i++){
                    ticket.sale();
                }
            }
        },"BB").start();

        new Thread(new Runnable() {
            @Override
            public void run() {
                // Call ticket selling method 
                for(int i=0;i<40;i++){
                    ticket.sale();
                }
            }
        },"CC").start();
    }
}

2.ReentrantLock

package juc.two;

import java.util.concurrent.locks.ReentrantLock;

// First step   Create a resource class , Define properties and operation methods 
class LTicket {
    // Number of tickets 
    private int number = 30;

    // Create a reentrant lock 
    private final ReentrantLock lock = new ReentrantLock();
    // Ticket selling method 
    public void sale() {
        // locked 
        lock.lock();
        // Judge whether there is a ticket 
        if(number > 0){
            System.out.println(Thread.currentThread().getName()+" ： sell "+(number--)+"  The remaining ："+number);
        }
        // Unlock 
        lock.unlock();
    }
}

public class LSaleTicket {
    // The second step   Create multiple threads , Call the operation method of the resource class 
    // Create three threads 
    public static void main(String[] args) {
        LTicket ticket  = new LTicket();

        new Thread(()->{
            for(int i = 0; i < 40; i++){
                ticket.sale();
            }
        },"AA").start();

        new Thread(()->{
            for(int i = 0; i < 40; i++){
                ticket.sale();
            }
        },"BB").start();

        new Thread(()->{
            for(int i = 0; i < 40; i++){
                ticket.sale();
            }
        },"CC").start();
    }
}