分布式锁（Redis实现 及zookeep实现）

基于Redis实现

1 .引入相关组件

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-integration</artifactId>
</dependency>

<dependency>
 <groupId>org.springframework.integration</groupId>
 <artifactId>spring-integration-redis</artifactId>
</dependency>

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

2 . 在application.yml中添加redis的配置

在application.yml中添加redis的配置
spring:
 redis:
  host: 127.0.0.1
  port: 6379

3 . 建立配置类，注入RedisLockRegistry

@Configuration
public class RedisLockConfiguration {

    @Bean
    public RedisLockRegistry redisLockRegistry(RedisConnectionFactory redisConnectionFactory){
        return new RedisLockRegistry(redisConnectionFactory, "redis-lock");
    }

}

4. 编写测试代码

@RestController
@RequestMapping("lock")
@Log4j2
public class DistributedLockController {
    @Autowired
    private RedisLockRegistry redisLockRegistry;

    @GetMapping("/redis")
    public void test1() {
        Lock lock = redisLockRegistry.obtain("redis-product");
        try{
            //尝试在指定时间内加锁，如果已经有其他锁锁住，获取当前线程不能加锁，则返回false，加锁失败；加锁成功则返回true
            if(lock.tryLock(3, TimeUnit.SECONDS)){
                log.info("lock is ready");
                dowork();//业务代码
            }
        } catch (InterruptedException e) {
            log.error("obtain lock error",e);
        } finally {
            lock.unlock();
        }
    }
}

如果出现下面事列

说明第二个实例没有拿到锁，证明了分布式锁的存在。

二 基于Zookeeper实现

1 .引入组件

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-integration</artifactId>
</dependency>

 <dependency>
 <groupId>org.springframework.integration</groupId>
 <artifactId>spring-integration-zookeeper</artifactId>
</dependency>

2 . 在application.yml中添加zookeeper的配置

zookeeper:  
    host: 127.0.0.1:2181

3 . 建立配置类，注入ZookeeperLockRegistry

@Configuration
public class ZookeeperLockConfiguration {
    @Value("${zookeeper.host}")
    private String zkUrl;


    @Bean
    public CuratorFrameworkFactoryBean curatorFrameworkFactoryBean(){
        return new CuratorFrameworkFactoryBean(zkUrl);
    }

    @Bean
    public ZookeeperLockRegistry zookeeperLockRegistry(CuratorFramework curatorFramework){
        return new ZookeeperLockRegistry(curatorFramework,"/zookeeper-lock");
    }
}

4 . 编写测试代码

@RestController
@RequestMapping("lock")
@Log4j2
public class DistributedLockController {

    @Autowired
    private ZookeeperLockRegistry zookeeperLockRegistry;

    @GetMapping("/zookeeper")
    public void test2() {
        Lock lock = zookeeperLockRegistry.obtain("zookeeper");
        try{
            //尝试在指定时间内加锁，如果已经有其他锁锁住，获取当前线程不能加锁，则返回false，加锁失败；加锁成功则返回true
            if(lock.tryLock(3, TimeUnit.SECONDS)){
                log.info("lock is ready");
                dowork();//业务代码
            }
        } catch (InterruptedException e) {
            log.error("obtain lock error",e);
        } finally {
            lock.unlock();
        }
    }
}

验证的结果与reids相同