public S3AsyncEncryptionClient build()

in src/main/java/software/amazon/encryption/s3/S3AsyncEncryptionClient.java [789:873]
73 lines of code
12 McCabe index (conditional complexity)

        public S3AsyncEncryptionClient build() {
            if (!onlyOneNonNull(_cryptoMaterialsManager, _keyring, _aesKey, _rsaKeyPair, _kmsKeyId)) {
                throw new S3EncryptionClientException("Exactly one must be set of: crypto materials manager, keyring, AES key, RSA key pair, KMS key id");
            }

            if (_bufferSize >= 0) {
                if (_enableDelayedAuthenticationMode) {
                    throw new S3EncryptionClientException("Buffer size cannot be set when delayed authentication mode is enabled");
                }
            } else {
                _bufferSize = DEFAULT_BUFFER_SIZE_BYTES;
            }

            if (_wrappedClient == null) {
                _wrappedClient = S3AsyncClient.builder()
                        .credentialsProvider(_awsCredentialsProvider)
                        .region(_region)
                        .dualstackEnabled(_dualStackEnabled)
                        .fipsEnabled(_fipsEnabled)
                        .overrideConfiguration(_overrideConfiguration)
                        .endpointOverride(_endpointOverride)
                        .asyncConfiguration(_clientAsyncConfiguration != null ? _clientAsyncConfiguration : ClientAsyncConfiguration.builder().build())
                        .httpClient(_sdkAsyncHttpClient)
                        .httpClientBuilder(_sdkAsyncHttpClientBuilder)
                        .serviceConfiguration(_serviceConfiguration)
                        .accelerate(_accelerate)
                        .disableMultiRegionAccessPoints(_disableMultiRegionAccessPoints)
                        .disableS3ExpressSessionAuth(_disableS3ExpressSessionAuth)
                        .forcePathStyle(_forcePathStyle)
                        .useArnRegion(_useArnRegion)
                        .crossRegionAccessEnabled(_crossRegionAccessEnabled)
                        // If either of these are null, the AWS SDK will throw an exception.
                        // Since there is no way to set them without an exception being thrown,
                        // this would always result in an exception.
                        // .multipartEnabled(_multipartEnabled)
                        // .multipartConfiguration(_multipartConfiguration)
                        .build();
            }

            if (_instructionFileConfig == null) {
                _instructionFileConfig = InstructionFileConfig.builder()
                        .instructionFileAsyncClient(_wrappedClient)
                        .build();
            }

            if (_keyring == null) {
                if (_aesKey != null) {
                    _keyring = AesKeyring.builder()
                            .wrappingKey(_aesKey)
                            .enableLegacyWrappingAlgorithms(_enableLegacyWrappingAlgorithms)
                            .secureRandom(_secureRandom)
                            .build();
                } else if (_rsaKeyPair != null) {
                    _keyring = RsaKeyring.builder()
                            .wrappingKeyPair(_rsaKeyPair)
                            .enableLegacyWrappingAlgorithms(_enableLegacyWrappingAlgorithms)
                            .secureRandom(_secureRandom)
                            .build();
                } else if (_kmsKeyId != null) {
                    KmsClient kmsClient = KmsClient.builder()
                            .credentialsProvider(_awsCredentialsProvider)
                            .region(_region)
                            .dualstackEnabled(_dualStackEnabled)
                            .fipsEnabled(_fipsEnabled)
                            .overrideConfiguration(_overrideConfiguration)
                            .build();

                    _keyring = KmsKeyring.builder()
                            .kmsClient(kmsClient)
                            .wrappingKeyId(_kmsKeyId)
                            .enableLegacyWrappingAlgorithms(_enableLegacyWrappingAlgorithms)
                            .secureRandom(_secureRandom)
                            .build();
                }
            }

            if (_cryptoMaterialsManager == null) {
                _cryptoMaterialsManager = DefaultCryptoMaterialsManager.builder()
                        .keyring(_keyring)
                        .cryptoProvider(_cryptoProvider)
                        .build();
            }

            return new S3AsyncEncryptionClient(this);
        }