ConfigController：configs/{appId}/{clusterName}/{namespace}：提供配置读取功能

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目录

概 述

@GetMapping(value = "/{appId}/{clusterName}/{namespace:.+}")
  public ApolloConfig queryConfig(@PathVariable String appId, @PathVariable String clusterName,
                                  @PathVariable String namespace,
                                  @RequestParam(value = "dataCenter", required = false) String dataCenter,
                                  @RequestParam(value = "releaseKey", defaultValue = "-1") String clientSideReleaseKey,
                                  @RequestParam(value = "ip", required = false) String clientIp,
                                  @RequestParam(value = "messages", required = false) String messagesAsString,
                                  HttpServletRequest request, HttpServletResponse response) throws IOException {
    String originalNamespace = namespace;
    //strip out .properties suffix
	   若 Namespace 名以 .properties 结尾，移除该结尾，并设置到 ApolloConfigNotification 中
    namespace = namespaceUtil.filterNamespaceName(namespace);
    //fix the character case issue, such as FX.apollo <-> fx.apollo
	  // 获得归一化的 Namespace 名字。因为，客户端 Namespace 会填写错大小写。
    namespace = namespaceUtil.normalizeNamespace(appId, namespace);
 
    if (Strings.isNullOrEmpty(clientIp)) {
      clientIp = tryToGetClientIp(request);
    }
	  // 解析 messagesAsString 参数，创建 ApolloNotificationMessages 对象。
    ApolloNotificationMessages clientMessages = transformMessages(messagesAsString);
 
    List<Release> releases = Lists.newLinkedList();
 
    String appClusterNameLoaded = clusterName;
    if (!ConfigConsts.NO_APPID_PLACEHOLDER.equalsIgnoreCase(appId)) {
		// 获得 Release 对象
      Release currentAppRelease = configService.loadConfig(appId, clientIp, appId, clusterName, namespace,
          dataCenter, clientMessages);
 
      if (currentAppRelease != null) {
        releases.add(currentAppRelease);
        //we have cluster search process, so the cluster name might be overridden
        appClusterNameLoaded = currentAppRelease.getClusterName();
      }
    }
 
    //if namespace does not belong to this appId, should check if there is a public configuration
	  // 若 Namespace 为关联类型，则获取关联的 Namespace 的 Release 对象
    if (!namespaceBelongsToAppId(appId, namespace)) {
      Release publicRelease = this.findPublicConfig(appId, clientIp, clusterName, namespace,
          dataCenter, clientMessages);
      if (!Objects.isNull(publicRelease)) {
        releases.add(publicRelease);
      }
    }
 
    if (releases.isEmpty()) {
      response.sendError(HttpServletResponse.SC_NOT_FOUND,
          String.format(
              "Could not load configurations with appId: %s, clusterName: %s, namespace: %s",
              appId, clusterName, originalNamespace));
      Tracer.logEvent("Apollo.Config.NotFound",
          assembleKey(appId, clusterName, originalNamespace, dataCenter));
      return null;
    }
 
    auditReleases(appId, clusterName, dataCenter, clientIp, releases);
 
    String mergedReleaseKey = releases.stream().map(Release::getReleaseKey)
            .collect(Collectors.joining(ConfigConsts.CLUSTER_NAMESPACE_SEPARATOR));
	  // 对比 Client 的合并 Release Key 。若相等，说明没有改变，返回状态码为 304 的响应
    if (mergedReleaseKey.equals(clientSideReleaseKey)) {
      // Client side configuration is the same with server side, return 304
      response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
      Tracer.logEvent("Apollo.Config.NotModified",
          assembleKey(appId, appClusterNameLoaded, originalNamespace, dataCenter));
      return null;
    }
 
    ApolloConfig apolloConfig = new ApolloConfig(appId, appClusterNameLoaded, originalNamespace,
        mergedReleaseKey);
	  // 如果有变更，合并 Release 的配置，并将结果设置到 ApolloConfig 中
    apolloConfig.setConfigurations(mergeReleaseConfigurations(releases));
 
    Tracer.logEvent("Apollo.Config.Found", assembleKey(appId, appClusterNameLoaded,
        originalNamespace, dataCenter));
    return apolloConfig;
  }
总结：

1、基本就是根据条件获取服务端配置 生成Release Key

2、跟客户端传过来的做对比，如果有变更就返回，无变更返回403

 

 

总结：
1、基本就是根据条件获取服务端配置 生成Release Key

2、跟客户端传过来的做对比，如果有变更就返回，无变更返回403

小结

ConfigController：configs/{appId}/{clusterName}/{namespace}：提供配置读取功能

参考资料和推荐阅读

1.链接: 参考资料.