springboot+zookeeper實現分散式鎖的範例程式碼

<dependency>
   <groupId>org.apache.zookeeper</groupId>
   <artifactId>zookeeper</artifactId>
   <version>3.4.10</version>
</dependency>
<!-- zookeeper 使用者端 -->
<dependency>
   <groupId>org.apache.curator</groupId>
   <artifactId>curator-framework</artifactId>
   <version>2.12.0</version>
</dependency>
<dependency>
   <groupId>org.apache.curator</groupId>
   <artifactId>curator-recipes</artifactId>
   <version>2.12.0</version>
</dependency>
<!-- lombok -->
<dependency>
   <groupId>org.projectlombok</groupId>
   <artifactId>lombok</artifactId>
   <version>1.18.16</version>
   <scope>provided</scope>
</dependency>

@Slf4j
public class CuratorClientUtil {
    private String zookeeperServer;

    @Getter
    private CuratorFramework client;

    public CuratorClientUtil(String zookeeperServer) {
        this.zookeeperServer = zookeeperServer;
    }

  	// 建立CuratorFrameworkFactory並且啟動
    public void init() {
       // 重試策略,等待1s,最大重試3次
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,3);
        this.client = CuratorFrameworkFactory.builder()
                .connectString(zookeeperServer)
                .sessionTimeoutMs(5000)
                .connectionTimeoutMs(5000)
                .retryPolicy(retryPolicy)
                .build();
        this.client.start();
    }

   // 容器關閉,CuratorFrameworkFactory關閉
    public void destroy() {
        try {
            if (Objects.nonNull(getClient())) {
                getClient().close();
            }
        } catch (Exception e) {
            log.info("CuratorFramework close error=>{}", e.getMessage());
        }
    }
}

@Configuration
public class CuratorConfigration {
    @Value("${zookeeper.server}")
    private String zookeeperServer;
    // 注入時,指定initMethod和destroyMethod
    @Bean(initMethod = "init", destroyMethod = "destroy")
    public CuratorClientUtil curatorClientUtil() {
        CuratorClientUtil clientUtil = new CuratorClientUtil(zookeeperServer);
        return clientUtil;
    }
}

@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {
    // 注入client工具類
    @Autowired
    private CuratorClientUtil curatorClientUtil;
    // 在zookeeper的/rootLock節點下建立鎖對應的臨時有序節點
    private String rootLock = "/rootLock";

    @GetMapping("/testLock")
    public Object testLock() throws Exception {
        // 獲取當前執行緒的名字，方便觀察那些執行緒在獲取鎖
        String threadName = Thread.currentThread().getName();
        InterProcessMutex mutex = new InterProcessMutex(curatorClientUtil.getClient(), rootLock);
        try {
            log.info("{}---獲取鎖start", threadName);
            // 嘗試獲取鎖，最長等待3s，超時放棄獲取
            boolean lockFlag = mutex.acquire(3000, TimeUnit.SECONDS);
            // 獲取鎖成功，進行業務處理
            if (lockFlag) {
                log.info("{}---獲取鎖success", threadName);
                // 模擬業務處理，時間為3s
                Thread.sleep(3000);
            } else {
                log.info("{}---獲取鎖fail", threadName);
            }
        } catch (Exception e) {
            log.info("{}---獲取鎖異常", threadName);
        } finally {
            // 業務處理完成，釋放鎖，喚醒比當前執行緒建立的節點序號大(最靠近)的執行緒獲取鎖
            mutex.release();
            log.info("{}---鎖release", threadName);
        }
        return "執行緒:" + threadName + "執行完成";
    }
}