protected AWSCredentialsProvider getAWSCredentialsProvider()

in emr-dynamodb-hadoop/src/main/java/org/apache/hadoop/dynamodb/DynamoDBClient.java [389:454]
56 lines of code
7 McCabe index (conditional complexity)

  protected AWSCredentialsProvider getAWSCredentialsProvider(Configuration conf) {
    List<AWSCredentialsProvider> providersList = new ArrayList<>();

    // try to load custom credential provider, fail if a provider is specified but cannot be
    // initialized
    String providerClass = conf.get(DynamoDBConstants.CUSTOM_CREDENTIALS_PROVIDER_CONF);
    if (!Strings.isNullOrEmpty(providerClass)) {
      try {
        providersList.add(
            (AWSCredentialsProvider) ReflectionUtils.newInstance(Class.forName(providerClass), conf)
        );
      } catch (ClassNotFoundException e) {
        throw new RuntimeException("Custom AWSCredentialsProvider not found: " + providerClass, e);
      }
    }

    // try to fetch credentials from core-site
    String accessKey = conf.get(DYNAMODB_SESSION_CREDENTIAL_PAIR_NAME.getAccessKeyName());
    String secretKey;
    String sessionKey;
    if (Strings.isNullOrEmpty(accessKey)) {
      accessKey = conf.get(DEFAULT_CREDENTIAL_PAIR_NAME.getAccessKeyName());
      secretKey = conf.get(DEFAULT_CREDENTIAL_PAIR_NAME.getSecretKeyName());
      sessionKey = null;
    } else {
      secretKey = conf.get(DYNAMODB_SESSION_CREDENTIAL_PAIR_NAME.getSecretKeyName());
      sessionKey = conf.get(DYNAMODB_SESSION_CREDENTIAL_PAIR_NAME.getSessionKeyName());
    }

    if (Strings.isNullOrEmpty(accessKey) || Strings.isNullOrEmpty(secretKey)) {
      providersList.add(new InstanceProfileCredentialsProvider());
    } else if (!Strings.isNullOrEmpty(sessionKey)) {
      final AWSCredentials credentials =
          new BasicSessionCredentials(accessKey, secretKey, sessionKey);
      providersList.add(new AWSCredentialsProvider() {
        @Override
        public AWSCredentials getCredentials() {
          return credentials;
        }

        @Override
        public void refresh() {
        }
      });
    } else {
      final AWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);
      providersList.add(new AWSCredentialsProvider() {
        @Override
        public AWSCredentials getCredentials() {
          return credentials;
        }

        @Override
        public void refresh() {
        }
      });
    }

    AWSCredentialsProvider[] providerArray = providersList.toArray(
        new AWSCredentialsProvider[providersList.size()]
    );

    AWSCredentialsProviderChain providerChain = new AWSCredentialsProviderChain(providerArray);
    providerChain.setReuseLastProvider(true);
    return providerChain;
  }