public List readShardingConfig()

in spanner-data-validator-java/src/main/java/com/google/migration/common/ShardFileReader.java [95:171]
69 lines of code
7 McCabe index (conditional complexity)

  public List<Shard> readShardingConfig(String sourceShardsFilePath) {
    String jsonString = null;
    try {
      InputStream stream =
          Channels.newInputStream(
              FileSystems.open(FileSystems.matchNewResource(sourceShardsFilePath, false)));

      jsonString = IOUtils.toString(stream, StandardCharsets.UTF_8);
    } catch (IOException e) {
      LOG.error(
          "Failed to read shard input file. Make sure it is ASCII or UTF-8 encoded and contains a"
              + " well-formed JSON string.",
          e);
      throw new RuntimeException(
          "Failed to read shard input file. Make sure it is ASCII or UTF-8 encoded and contains a"
              + " well-formed JSON string.",
          e);
    }

    // TODO - create a structure for the shard config and map directly to the object
    Type shardConfiguration = new TypeToken<Map>() {}.getType();
    Map shardConfigMap =
        new GsonBuilder()
            .setFieldNamingPolicy(FieldNamingPolicy.IDENTITY)
            .setObjectToNumberStrategy(ToNumberPolicy.LONG_OR_DOUBLE)
            .create()
            .fromJson(jsonString, shardConfiguration);

    List<Shard> shardList = new ArrayList<>();
    List<Map> dataShards =
        (List)
            (((Map) shardConfigMap.getOrDefault("shardConfigurationBulk", new HashMap<>()))
                .getOrDefault("dataShards", new ArrayList<>()));

    for (Map dataShard : dataShards) {
      List<Map> databases = (List) (dataShard.getOrDefault("databases", new ArrayList<>()));

      String host = (String) (dataShard.get("host"));
      if (databases.isEmpty()) {
        LOG.warn("no databases found for host: {}", host);
        throw new RuntimeException("no databases found for host: " + String.valueOf(host));
      }

      String password =
          resolvePassword(
              sourceShardsFilePath,
              (String) dataShard.get("secretManagerUri"),
              host,
              (String) dataShard.get("password"));
      if (password == null || password.isEmpty()) {
        LOG.warn("could not fetch password for host: {}", host);
        throw new RuntimeException(
            "Neither password nor secretManagerUri was found in the shard file "
                + sourceShardsFilePath
                + "  for host "
                + host);
      }
      String namespace =
          Optional.ofNullable(dataShard.get("namespace")).map(Object::toString).orElse(null);

      for (Map database : databases) {
        Shard shard =
            new Shard(
                database.getOrDefault("databaseId", database.get("dbName")).toString(),
                host,
                dataShard.getOrDefault("port", 0).toString(),
                (String) (dataShard.get("user")),
                password,
                database.get("dbName").toString(),
                namespace,
                (String) (dataShard.get("secretManagerUri")),
                dataShard.getOrDefault("connectionProperties", "").toString());
        shardList.add(shard);
      }
    }
    return shardList;
  }