可重入锁 可重入锁可重入锁：打开大门的锁之后也就获得了里面两个房间的锁synchronized版可重入锁package com.sw.lock; /** * @Author suaxi * @Date 2021/2/22 23:07 * synchronized版可重入锁 */ public class Test01 { public static void main(String[] args) { Phone phone = new Phone(); new Thread(() ->{ phone.sms(); },"A").start(); new Thread(() ->{ phone.sms(); },"B").start(); } } class Phone{ public synchronized void sms(){ System.out.println(Thread.currentThread().getName()+"--->sms"); call(); } public synchronized void call(){ System.out.println(Thread.currentThread().getName()+"--->call"); } } lock版可重入锁package com.sw.lock; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; /** * @Author suaxi * @Date 2021/2/22 23:07 * lock版可重入锁 */ public class Test02 { public static void main(String[] args) { Phone2 phone = new Phone2(); new Thread(() ->{ phone.sms(); },"A").start(); new Thread(() ->{ phone.sms(); },"B").start(); } } class Phone2{ Lock lock =new ReentrantLock(); public void sms(){ lock.lock(); //lock锁必须配对，否则会产生死锁 try { System.out.println(Thread.currentThread().getName()+"--->sms"); call(); }catch (Exception e){ e.printStackTrace(); }finally { lock.unlock(); } } public void call(){ lock.lock(); try { System.out.println(Thread.currentThread().getName()+"--->call"); }catch (Exception e){ e.printStackTrace(); }finally { lock.unlock(); } } }