public static AwsIotMqtt5ClientBuilder newWebsocketMqttBuilderWithSigv4Auth()

in sdk/src/main/java/software/amazon/awssdk/iot/AwsIotMqtt5ClientBuilder.java [225:280]
44 lines of code
6 McCabe index (conditional complexity)

    public static AwsIotMqtt5ClientBuilder newWebsocketMqttBuilderWithSigv4Auth(String hostName, WebsocketSigv4Config config) {
        TlsContextOptions options = TlsContextOptions.createDefaultClient();
        options.alpnList.clear();

        AwsIotMqtt5ClientBuilder builder = new AwsIotMqtt5ClientBuilder(hostName, DEFAULT_WEBSOCKET_MQTT_PORT, options);
        options.close();

        CredentialsProvider provider = null;
        if (config != null) {
            provider = config.credentialsProvider;
        }

        try (AwsSigningConfig signingConfig = new AwsSigningConfig()) {
            signingConfig.setAlgorithm(AwsSigningAlgorithm.SIGV4);
            signingConfig.setSignatureType(AwsSignatureType.HTTP_REQUEST_VIA_QUERY_PARAMS);

            if (provider != null) {
                signingConfig.setCredentialsProvider(provider);
            } else {
                DefaultChainCredentialsProvider.DefaultChainCredentialsProviderBuilder providerBuilder = new DefaultChainCredentialsProvider.DefaultChainCredentialsProviderBuilder();
                providerBuilder.withClientBootstrap(ClientBootstrap.getOrCreateStaticDefault());
                try (CredentialsProvider defaultProvider = providerBuilder.build()) {
                    signingConfig.setCredentialsProvider(defaultProvider);
                }
            }

            if (config != null) {
                if (config.region != null) {
                    signingConfig.setRegion(config.region);
                } else {
                    signingConfig.setRegion(extractRegionFromEndpoint(hostName));
                }
            } else {
                signingConfig.setRegion(extractRegionFromEndpoint(hostName));
            }
            signingConfig.setService("iotdevicegateway");
            signingConfig.setOmitSessionToken(true);
            // Needs to stay alive as long as the MQTT5 client, which we can allow by pinning
            // the resource to the signingConfig
            options.addReferenceTo(signingConfig);

            try (AwsMqtt5Sigv4HandshakeTransformer transformer = new AwsMqtt5Sigv4HandshakeTransformer(signingConfig)) {
                builder.config.withWebsocketHandshakeTransform(transformer);
                // Needs to stay alive as long as the MQTT5 client, which we can allow by pinning
                // the resource to the signingConfig
                options.addReferenceTo(transformer);
            }

        } catch (Exception ex) {
            System.out.println("Error - exception occurred while making Websocket Sigv4 builder: " + ex.toString());
            ex.printStackTrace();
            return null;
        }

        return builder;
    }