CuratorFramework实现zk同步本地配置

Posted 2021-11-23 ITdfq

SpringBoot连接Zk

---

连接配置

• pom文件导入

  <!--            zk客户端-->
          <dependency>
              <groupId>org.apache.curator</groupId>
              <artifactId>curator-recipes</artifactId>
              <version>4.3.0</version>
          </dependency>
          <dependency>
              <groupId>org.apache.curator</groupId>
              <artifactId>curator-framework</artifactId>
              <version>4.0.1</version>
          </dependency>
  
          <dependency>
              <groupId>org.apache.curator</groupId>
              <artifactId>curator-client</artifactId>
              <version>4.0.1</version>
              <exclusions>
                  <exclusion>
                      <groupId>log4j</groupId>
                      <artifactId>log4j</artifactId>
                  </exclusion>
              </exclusions>
          </dependency>
  

• 连接配置

  zk:
    url: ###
    projectName: /itdfq/zookeeperDemo
    #休眠时间
    baseSleepTimeMs: 1000
    #失败重试次数
    maxRetries: 3
  

• 连接设置

  
      /**
       * Zookeeper 框架式客户端
       *
       * @return CuratorFramework
       */
      @Bean
      public CuratorFramework getCuratorFramework() {
          //重试策略
          RetryPolicy retryPolicy = new ExponentialBackoffRetry(zkProperties.getBaseSleepTimeMs(), zkProperties.getMaxRetries());
          return CuratorFrameworkFactory.newClient(zkProperties.getUrl(), retryPolicy);
      }
  
      /**
       * 监视 ZK
       *
       * @return TreeCache
       */
      @Bean
      public TreeCache getTreeCache() {
          return new TreeCache(curatorFramework, zkProperties.getProjectName());
      }
  

• 初始化

    @Autowired
      private CuratorFramework curatorFramework;
      @Autowired
      private TreeCache treeCache;
      /**
       * 本地配置
       */
      private final Properties properties = new Properties();
  
      @PostConstruct
      public void loadProperties() {
          try {
              log.info("================初始化配置=================");
              curatorFramework.start();
              treeCache.start();
              // 从zk中获取配置放入本地配置中
              Stat stat = curatorFramework.checkExists().forPath(zkProperties.getProjectName());
              if (stat == null) {
                  curatorFramework.create().forPath(zkProperties.getProjectName());
              }
              List<String> configList = curatorFramework.getChildren().forPath(zkProperties.getProjectName());
              log.info("配置参数：{}", JSON.toJSONString(configList));
              for (String s : configList) {
                  byte[] value = curatorFramework.getData().forPath(zkProperties.getProjectName() + ZkConstant.SEPARATOR + s);
                  log.info("节点:【{}】   key：【{}】   Value:【{}】 ", zkProperties.getProjectName() + ZkConstant.SEPARATOR + s, s, new String(value));
                  properties.setProperty(s, new String(value));
              }
  
              // 监听属性值变更
              treeCache.getListenable().addListener(new TreeCacheListener() {
                  @Override
                  public void childEvent(CuratorFramework curatorFramework, TreeCacheEvent treeCacheEvent) throws Exception {
                      if (Objects.equals(treeCacheEvent.getType(), TreeCacheEvent.Type.NODE_ADDED) ||
                              Objects.equals(treeCacheEvent.getType(), TreeCacheEvent.Type.NODE_UPDATED)) {
                          String updateKey = treeCacheEvent.getData().getPath().replace(zkProperties.getProjectName() + ZkConstant.SEPARATOR, "");
                          properties.setProperty(updateKey, new String(treeCacheEvent.getData().getData()));
                          log.info("数据更新：更新类型【{}】，更新的key:【{}】,更新value:【{}】", treeCacheEvent.getType(), zkProperties.getProjectName() + ZkConstant.SEPARATOR + updateKey, new String(treeCacheEvent.getData().getData()));
                      }
                  }
              });
  
          } catch (Exception e) {
              log.error("zk配置初始化异常", e);
          }
      }
  

get/set方法

    /**
     * 获取同步配置属性
     * </p>
     * zk的value保存在本地缓存
     *
     * @param key zk-Key
     * @return String
     */
    public String getProperties(String key) {
        return properties.getProperty(key);
    }

    /**
     * 获取zk的节点value
     * </>
     *
     * @return String
     */
    public String getZkValue(String key) {
        try {
            byte[] bytes = curatorFramework.getData().forPath(zkProperties.getProjectName() + ZkConstant.SEPARATOR + key);
            return new String(bytes);
        } catch (Exception e) {
            return null;
        }
    }

    /**
     * 设置zk的key value
     * <p>
     * 如果项目启动，会同步更新本地配置缓存
     *
     * @param key
     * @param value
     * @return
     */
    public Boolean setZkValue(String key, String value) {
        try {
            String propertiesKey = zkProperties.getProjectName() + ZkConstant.SEPARATOR + key;
            Stat stat = curatorFramework.checkExists().forPath(propertiesKey);
            if (stat == null) {
                curatorFramework.create().forPath(propertiesKey);
            }
            curatorFramework.setData().forPath(propertiesKey, value.getBytes());
            return Boolean.TRUE;
        } catch (Exception e) {
            return Boolean.FALSE;
        }
    }

分布式锁

   /**
     * 分布式锁 对象
     * <p/>
     * 互斥锁
     *
     * @param path
     * @return
     */
    public InterProcessMutex getLock(String path) {
        InterProcessMutex lock = null;
        try {
            lock = new InterProcessMutex(curatorFramework, zkProperties.getProjectName() + ZkConstant.SEPARATOR + path);
            return lock;
        } catch (Exception e) {
            log.error("获取锁失败", e);
        }
        return null;
    }

实现结果

• 项目启动初始化
  
• 在zk中改个配置
  
• 结果
  
• 在线获取配置

  @RequestMapping("/get/{key}")
    public String get(@PathVariable("key") String key) {
        log.info("请求参数：{}", key);
        return "结果：" + zkApi.getProperties(key);
    }