A single node obtains the lock lock of the order number

effect ：

100 Threads get the order number at the same time

1, establish OrderService class

package com.hyw.service;

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

public class OrderService implements Runnable {
    static Integer number = 50000000;   // Initialization order No 
    private Lock lock = new ReentrantLock();

    @Override
    public void run() {
        getNumber();
    }

    private void getNumber(){
        try {
            lock.lock();
            String number = generatorNumber();
            System.out.println(Thread.currentThread()+", Acquired number:"+number);
        } finally {
            lock.unlock();
        }
    }

    /**
     *  Generate order number 
     * @return
     */
    static String generatorNumber(){
        String dh = " Odd Numbers ："+number;
        number ++;

        return dh;
    }
}

2. simulation 100 Threads generate order numbers

package com.hyw.lock;

import com.hyw.service.OrderService;

public class TestMain {
    public static void main(String[] args) {
        for (int i = 0; i < 100; i++) {
            new Thread(new OrderService()).start();
        }
    }
}

Running results ：