Lock use the interface to solve thread safety issues

cn.itcast.demo16.Demo09.Lock Package ; 

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

/ ** 
* @author newcityman 
* @date 2019/7/24 - 20 is : 38 
* solve thread safety issues third option: use lock lock 
* java.util.concurrent.locks.lock Interface 
* lock implementations provide more extensive locking available than using synchronized methods and statements operation 
* lock interface method: 
* void lock () Get lock 
* void unlock () releases the lock 
* java.util.concurrent.Locks.ReentrantLock implements lock Interface 
* 
* the procedures: 
* 1, create a ReentrantLock implement lock interface occupant position 
* 2, call lock lock the interface method may appear before the code security issues acquire lock 
* 3, call unLock method releases the lock lock interface in the code after the security issues that may arise
 */
public class RunnableImpl implements java.lang.Runnable {
 private int ticket = 100;

 Lock l = new ReentrantLock();

 @Override
 public void run() {
 while (true) {
 l.lock();
 try {
 Thread.sleep(10);
 if (ticket > 0) {
 System.out.println(Thread.currentThread().getName() + "--->正在卖" + ticket + "张票");
 ticket--;
 }
 } catch (InterruptedException e) {
 e.printStackTrace();
 } catch (Exception e) {
 e.printStackTrace();
 } finally {
 l.unlock();
 }
 }
 }
}

package cn.itcast.demo16.Demo09.Lock;

/**
 * @author newcityman
 * @date 2019/7/24 - 20:44
 */
public class Demo01TicketLock {
 public static void main(String[] args) {
 RunnableImpl impl = new RunnableImpl();
 Thread t1 = new Thread(impl);
 Thread t2 = new Thread(impl);
 Thread t3 = new Thread(impl);

 t1.start();
 t2.start();
 t3.start();
 }
}