protected void init()

in wrapper/src/main/java/software/amazon/jdbc/hostlistprovider/RdsHostListProvider.java [140:215]
65 lines of code
13 McCabe index (conditional complexity)

  protected void init() throws SQLException {
    if (this.isInitialized) {
      return;
    }

    lock.lock();
    try {
      if (this.isInitialized) {
        return;
      }

      // initial topology is based on connection string
      this.initialHostList =
          connectionUrlParser.getHostsFromConnectionUrl(this.originalUrl, false,
              this.hostListProviderService::getHostSpecBuilder);
      if (this.initialHostList == null || this.initialHostList.isEmpty()) {
        throw new SQLException(Messages.get("RdsHostListProvider.parsedListEmpty",
            new Object[] {this.originalUrl}));
      }
      this.initialHostSpec = this.initialHostList.get(0);
      this.hostListProviderService.setInitialConnectionHostSpec(this.initialHostSpec);

      this.clusterId = UUID.randomUUID().toString();
      this.isPrimaryClusterId = false;
      this.refreshRateNano =
          TimeUnit.MILLISECONDS.toNanos(CLUSTER_TOPOLOGY_REFRESH_RATE_MS.getInteger(properties));

      HostSpecBuilder hostSpecBuilder = this.hostListProviderService.getHostSpecBuilder();
      String clusterInstancePattern = CLUSTER_INSTANCE_HOST_PATTERN.getString(this.properties);
      if (clusterInstancePattern != null) {
        this.clusterInstanceTemplate =
            ConnectionUrlParser.parseHostPortPair(clusterInstancePattern, () -> hostSpecBuilder);
      } else {
        this.clusterInstanceTemplate =
            hostSpecBuilder
                .host(rdsHelper.getRdsInstanceHostPattern(this.initialHostSpec.getHost()))
                .hostId(this.initialHostSpec.getHostId())
                .port(this.initialHostSpec.getPort())
                .build();
      }

      validateHostPatternSetting(this.clusterInstanceTemplate.getHost());

      this.rdsUrlType = rdsHelper.identifyRdsType(this.initialHostSpec.getHost());

      final String clusterIdSetting = CLUSTER_ID.getString(this.properties);
      if (!StringUtils.isNullOrEmpty(clusterIdSetting)) {
        this.clusterId = clusterIdSetting;
      } else if (rdsUrlType == RdsUrlType.RDS_PROXY) {
        // Each proxy is associated with a single cluster, so it's safe to use RDS Proxy Url as cluster
        // identification
        this.clusterId = this.initialHostSpec.getUrl();
      } else if (rdsUrlType.isRds()) {
        final ClusterSuggestedResult clusterSuggestedResult =
            getSuggestedClusterId(this.initialHostSpec.getHostAndPort());
        if (clusterSuggestedResult != null && !StringUtils.isNullOrEmpty(clusterSuggestedResult.clusterId)) {
          this.clusterId = clusterSuggestedResult.clusterId;
          this.isPrimaryClusterId = clusterSuggestedResult.isPrimaryClusterId;
        } else {
          final String clusterRdsHostUrl =
              rdsHelper.getRdsClusterHostUrl(this.initialHostSpec.getHost());
          if (!StringUtils.isNullOrEmpty(clusterRdsHostUrl)) {
            this.clusterId = this.clusterInstanceTemplate.isPortSpecified()
                ? String.format("%s:%s", clusterRdsHostUrl, this.clusterInstanceTemplate.getPort())
                : clusterRdsHostUrl;
            this.isPrimaryClusterId = true;
            primaryClusterIdCache.put(this.clusterId, true, suggestedClusterIdRefreshRateNano);
          }
        }
      }

      this.isInitialized = true;
    } finally {
      lock.unlock();
    }
  }