AWS IoT examples using SDK for Java 2.x

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iot.IotClient;
import software.amazon.awssdk.services.iot.model.ListThingsRequest;
import software.amazon.awssdk.services.iot.model.ListThingsResponse;
import software.amazon.awssdk.services.iot.model.ThingAttribute;
import software.amazon.awssdk.services.iot.paginators.ListThingsIterable;

import java.util.List;

public class HelloIoT {
    public static void main(String[] args) {
        System.out.println("Hello AWS IoT. Here is a listing of your AWS IoT Things:");
        IotClient iotClient = IotClient.builder()
            .region(Region.US_EAST_1)
            .build();

        listAllThings(iotClient);
    }

    public static void listAllThings(IotClient iotClient) {
        iotClient.listThingsPaginator(ListThingsRequest.builder()
                .maxResults(10)
                .build())
            .stream()
            .flatMap(response -> response.things().stream())
            .forEach(attribute -> {
                System.out.println("Thing name: " + attribute.thingName());
                System.out.println("Thing ARN: " + attribute.thingArn());
            });
    }
}

Run an interactive scenario demonstrating AWS IoT features.

import java.util.Scanner;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 *
 * This Java example performs these tasks:
 *
 * 1. Creates an AWS IoT Thing.
 * 2. Generate and attach a device certificate.
 * 3. Update an AWS IoT Thing with Attributes.
 * 4. Get an AWS IoT Endpoint.
 * 5. List your certificates.
 * 6. Updates the shadow for the specified thing..
 * 7. Write out the state information, in JSON format
 * 8. Creates a rule
 * 9. List rules
 * 10. Search things
 * 11. Detach amd delete the certificate.
 * 12. Delete Thing.
 */
public class IotScenario {
    public static final String DASHES = new String(new char[80]).replace("\0", "-");

    public static void main(String[] args) {
        final String usage =
            """
                Usage:
                    <roleARN> <snsAction>

                Where:
                    roleARN - The ARN of an IAM role that has permission to work with AWS IOT.
                    snsAction  - An ARN of an SNS topic.
                """;

        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        IotActions iotActions = new IotActions();
        String thingName;
        String ruleName;
        String roleARN = args[0];
        String snsAction = args[1];
        Scanner scanner = new Scanner(System.in);

        System.out.println(DASHES);
        System.out.println("Welcome to the AWS IoT basics scenario.");
        System.out.println("""
            This example program demonstrates various interactions with the AWS Internet of Things (IoT) Core service. The program guides you through a series of steps, 
            including creating an IoT Thing, generating a device certificate, updating the Thing with attributes, and so on. 
            It utilizes the AWS SDK for Java V2 and incorporates functionality for creating and managing IoT Things, certificates, rules, 
            shadows, and performing searches. The program aims to showcase AWS IoT capabilities and provides a comprehensive example for 
            developers working with AWS IoT in a Java environment.
            
            Let's get started...
       
            """);
        System.out.println(DASHES);

        System.out.println("1. Create an AWS IoT Thing.");
        System.out.println("""
            An AWS IoT Thing represents a virtual entity in the AWS IoT service that can be associated with 
            a physical device.
            """);
        // Prompt the user for input.
        System.out.print("Enter Thing name: ");
        thingName = scanner.nextLine();
        iotActions.createIoTThing(thingName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("2. Generate a device certificate.");
        System.out.println("""
            A device certificate performs a role in securing the communication between devices (Things) 
            and the AWS IoT platform.
            """);

        System.out.print("Do you want to create a certificate for " +thingName +"? (y/n)");
        String certAns = scanner.nextLine();
        String certificateArn="" ;
        if (certAns != null && certAns.trim().equalsIgnoreCase("y")) {
            certificateArn = iotActions.createCertificate();
            System.out.println("Attach the certificate to the AWS IoT Thing.");
            iotActions.attachCertificateToThing(thingName, certificateArn);
        } else {
            System.out.println("A device certificate was not created.");
        }
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("3. Update an AWS IoT Thing with Attributes.");
        System.out.println("""
             IoT Thing attributes, represented as key-value pairs, offer a pivotal advantage in facilitating efficient data 
             management and retrieval within the AWS IoT ecosystem. 
            """);
        waitForInputToContinue(scanner);
        iotActions.updateShadowThing(thingName);
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("4. Return a unique endpoint specific to the Amazon Web Services account.");
        System.out.println("""
            An IoT Endpoint refers to a specific URL or Uniform Resource Locator that serves as the entry point for communication between IoT devices and the AWS IoT service.
           """);
        waitForInputToContinue(scanner);
        String endpointUrl = iotActions.describeEndpoint();
        System.out.println("The endpoint is "+endpointUrl);
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("5. List your AWS IoT certificates");
        waitForInputToContinue(scanner);
        if (certificateArn.length() > 0) {
            iotActions.listCertificates();
        } else {
            System.out.println("You did not create a certificates. Skipping this step.");
        }
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("6. Create an IoT shadow that refers to a digital representation or virtual twin of a physical IoT device");
        System.out.println("""
            A Thing Shadow refers to a feature that enables you to create a virtual representation, or "shadow," 
            of a physical device or thing. The Thing Shadow allows you to synchronize and control the state of a device between 
            the cloud and the device itself. and the AWS IoT service. For example, you can write and retrieve JSON data from a Thing Shadow. 
           """);
        waitForInputToContinue(scanner);
        iotActions.updateShadowThing(thingName);
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("7. Write out the state information, in JSON format.");
        waitForInputToContinue(scanner);
        iotActions.getPayload(thingName);
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("8. Creates a rule");
        System.out.println("""
        Creates a rule that is an administrator-level action. 
        Any user who has permission to create rules will be able to access data processed by the rule.
        """);
        System.out.print("Enter Rule name: ");
        ruleName = scanner.nextLine();
        iotActions.createIoTRule(roleARN, ruleName, snsAction);
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("9. List your rules.");
        waitForInputToContinue(scanner);
        iotActions.listIoTRules();
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("10. Search things using the Thing name.");
        waitForInputToContinue(scanner);
        String queryString = "thingName:"+thingName ;
        iotActions.searchThings(queryString);
        waitForInputToContinue(scanner);
        System.out.println(DASHES);

        System.out.println(DASHES);
        if (certificateArn.length() > 0) {
            System.out.print("Do you want to detach and delete the certificate for " +thingName +"? (y/n)");
            String delAns = scanner.nextLine();
            if (delAns != null && delAns.trim().equalsIgnoreCase("y")) {
                System.out.println("11. You selected to detach amd delete the certificate.");
                waitForInputToContinue(scanner);
                iotActions.detachThingPrincipal(thingName, certificateArn);
                iotActions.deleteCertificate(certificateArn);
                waitForInputToContinue(scanner);
            } else {
                System.out.println("11. You selected not to delete the certificate.");
            }
        } else {
            System.out.println("11. You did not create a certificate so there is nothing to delete.");
        }
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("12. Delete the AWS IoT Thing.");
        System.out.print("Do you want to delete the IoT Thing? (y/n)");
        String delAns = scanner.nextLine();
        if (delAns != null && delAns.trim().equalsIgnoreCase("y")) {
            iotActions.deleteIoTThing(thingName);
        } else {
            System.out.println("The IoT Thing was not deleted.");
        }
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("The AWS IoT workflow has successfully completed.");
        System.out.println(DASHES);
    }


    private static void waitForInputToContinue(Scanner scanner) {
        while (true) {
            System.out.println("");
            System.out.println("Enter 'c' followed by <ENTER> to continue:");
            String input = scanner.nextLine();

            if (input.trim().equalsIgnoreCase("c")) {
                System.out.println("Continuing with the program...");
                System.out.println("");
                break;
            } else {
                // Handle invalid input.
                System.out.println("Invalid input. Please try again.");
            }
        }
    }
}

A wrapper class for AWS IoT SDK methods.

import software.amazon.awssdk.auth.credentials.EnvironmentVariableCredentialsProvider;
import software.amazon.awssdk.core.SdkBytes;
import software.amazon.awssdk.core.client.config.ClientOverrideConfiguration;
import software.amazon.awssdk.core.retry.RetryPolicy;
import software.amazon.awssdk.http.async.SdkAsyncHttpClient;
import software.amazon.awssdk.http.nio.netty.NettyNioAsyncHttpClient;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iot.IotAsyncClient;
import software.amazon.awssdk.services.iot.model.Action;
import software.amazon.awssdk.services.iot.model.AttachThingPrincipalRequest;
import software.amazon.awssdk.services.iot.model.AttachThingPrincipalResponse;
import software.amazon.awssdk.services.iot.model.Certificate;
import software.amazon.awssdk.services.iot.model.CreateKeysAndCertificateResponse;
import software.amazon.awssdk.services.iot.model.CreateThingRequest;
import software.amazon.awssdk.services.iot.model.CreateThingResponse;
import software.amazon.awssdk.services.iot.model.CreateTopicRuleRequest;
import software.amazon.awssdk.services.iot.model.CreateTopicRuleResponse;
import software.amazon.awssdk.services.iot.model.DeleteCertificateRequest;
import software.amazon.awssdk.services.iot.model.DeleteCertificateResponse;
import software.amazon.awssdk.services.iot.model.DeleteThingRequest;
import software.amazon.awssdk.services.iot.model.DeleteThingResponse;
import software.amazon.awssdk.services.iot.model.DescribeEndpointRequest;
import software.amazon.awssdk.services.iot.model.DescribeEndpointResponse;
import software.amazon.awssdk.services.iot.model.DescribeThingRequest;
import software.amazon.awssdk.services.iot.model.DescribeThingResponse;
import software.amazon.awssdk.services.iot.model.DetachThingPrincipalRequest;
import software.amazon.awssdk.services.iot.model.DetachThingPrincipalResponse;
import software.amazon.awssdk.services.iot.model.IotException;
import software.amazon.awssdk.services.iot.model.ListCertificatesResponse;
import software.amazon.awssdk.services.iot.model.ListTopicRulesRequest;
import software.amazon.awssdk.services.iot.model.ListTopicRulesResponse;
import software.amazon.awssdk.services.iot.model.SearchIndexRequest;
import software.amazon.awssdk.services.iot.model.SearchIndexResponse;
import software.amazon.awssdk.services.iot.model.TopicRuleListItem;
import software.amazon.awssdk.services.iot.model.SnsAction;
import software.amazon.awssdk.services.iot.model.TopicRulePayload;
import software.amazon.awssdk.services.iotdataplane.IotDataPlaneAsyncClient;
import software.amazon.awssdk.services.iotdataplane.model.GetThingShadowRequest;
import software.amazon.awssdk.services.iotdataplane.model.GetThingShadowResponse;
import software.amazon.awssdk.services.iotdataplane.model.UpdateThingShadowRequest;
import software.amazon.awssdk.services.iotdataplane.model.UpdateThingShadowResponse;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class IotActions {

    private static IotAsyncClient iotAsyncClient;

    private static IotDataPlaneAsyncClient iotAsyncDataPlaneClient;

    private static final String TOPIC = "your-iot-topic";

    private static IotDataPlaneAsyncClient getAsyncDataPlaneClient() {
        SdkAsyncHttpClient httpClient = NettyNioAsyncHttpClient.builder()
            .maxConcurrency(100)
            .connectionTimeout(Duration.ofSeconds(60))
            .readTimeout(Duration.ofSeconds(60))
            .writeTimeout(Duration.ofSeconds(60))
            .build();

        ClientOverrideConfiguration overrideConfig = ClientOverrideConfiguration.builder()
            .apiCallTimeout(Duration.ofMinutes(2))
            .apiCallAttemptTimeout(Duration.ofSeconds(90))
            .retryPolicy(RetryPolicy.builder()
                .numRetries(3)
                .build())
            .build();

        if (iotAsyncDataPlaneClient == null) {
            iotAsyncDataPlaneClient = IotDataPlaneAsyncClient.builder()
                .region(Region.US_EAST_1)
                .httpClient(httpClient)
                .overrideConfiguration(overrideConfig)
                .credentialsProvider(EnvironmentVariableCredentialsProvider.create())
                .build();
        }
        return iotAsyncDataPlaneClient;
    }


    private static IotAsyncClient getAsyncClient() {
        SdkAsyncHttpClient httpClient = NettyNioAsyncHttpClient.builder()
            .maxConcurrency(100)
            .connectionTimeout(Duration.ofSeconds(60))
            .readTimeout(Duration.ofSeconds(60))
            .writeTimeout(Duration.ofSeconds(60))
            .build();

        ClientOverrideConfiguration overrideConfig = ClientOverrideConfiguration.builder()
            .apiCallTimeout(Duration.ofMinutes(2))
            .apiCallAttemptTimeout(Duration.ofSeconds(90))
            .retryPolicy(RetryPolicy.builder()
                .numRetries(3)
                .build())
            .build();

        if (iotAsyncClient == null) {
            iotAsyncClient = IotAsyncClient.builder()
                .region(Region.US_EAST_1)
                .httpClient(httpClient)
                .overrideConfiguration(overrideConfig)
                .credentialsProvider(EnvironmentVariableCredentialsProvider.create())
                .build();
        }
        return iotAsyncClient;
    }

    /**
     * Creates an IoT certificate asynchronously.
     *
     * @return The ARN of the created certificate.
     * <p>
     * This method initiates an asynchronous request to create an IoT certificate.
     * If the request is successful, it prints the certificate details and returns the certificate ARN.
     * If an exception occurs, it prints the error message.
     */
    public String createCertificate() {
        CompletableFuture<CreateKeysAndCertificateResponse> future = getAsyncClient().createKeysAndCertificate();
        final String[] certificateArn = {null};
        future.whenComplete((response, ex) -> {
            if (response != null) {
                String certificatePem = response.certificatePem();
                certificateArn[0] = response.certificateArn();

                // Print the details.
                System.out.println("\nCertificate:");
                System.out.println(certificatePem);
                System.out.println("\nCertificate ARN:");
                System.out.println(certificateArn[0]);

            } else {
                Throwable cause = (ex instanceof CompletionException) ? ex.getCause() : ex;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + cause.getMessage());
                }
            }
        });

        future.join();
        return certificateArn[0];
    }

    /**
     * Creates an IoT Thing with the specified name asynchronously.
     *
     * @param thingName The name of the IoT Thing to create.
     *
     * This method initiates an asynchronous request to create an IoT Thing with the specified name.
     * If the request is successful, it prints the name of the thing and its ARN value.
     * If an exception occurs, it prints the error message.
     */
    public void createIoTThing(String thingName) {
        CreateThingRequest createThingRequest = CreateThingRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<CreateThingResponse> future = getAsyncClient().createThing(createThingRequest);
        future.whenComplete((createThingResponse, ex) -> {
            if (createThingResponse != null) {
                System.out.println(thingName + " was successfully created. The ARN value is " + createThingResponse.thingArn());
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + cause.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Attaches a certificate to an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     * @param certificateArn The ARN of the certificate to attach.
     *
     * This method initiates an asynchronous request to attach a certificate to an IoT Thing.
     * If the request is successful, it prints a confirmation message and additional information about the Thing.
     * If an exception occurs, it prints the error message.
     */
    public void attachCertificateToThing(String thingName, String certificateArn) {
        AttachThingPrincipalRequest principalRequest = AttachThingPrincipalRequest.builder()
            .thingName(thingName)
            .principal(certificateArn)
            .build();

        CompletableFuture<AttachThingPrincipalResponse> future = getAsyncClient().attachThingPrincipal(principalRequest);
        future.whenComplete((attachResponse, ex) -> {
            if (attachResponse != null && attachResponse.sdkHttpResponse().isSuccessful()) {
                System.out.println("Certificate attached to Thing successfully.");

                // Print additional information about the Thing.
                describeThing(thingName);
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to attach certificate to Thing. HTTP Status Code: " +
                        attachResponse.sdkHttpResponse().statusCode());
                }
            }
        });

        future.join();
    }

    /**
     * Describes an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     *
     * This method initiates an asynchronous request to describe an IoT Thing.
     * If the request is successful, it prints the Thing details.
     * If an exception occurs, it prints the error message.
     */
    private void describeThing(String thingName) {
        DescribeThingRequest thingRequest = DescribeThingRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<DescribeThingResponse> future = getAsyncClient().describeThing(thingRequest);
        future.whenComplete((describeResponse, ex) -> {
            if (describeResponse != null) {
                System.out.println("Thing Details:");
                System.out.println("Thing Name: " + describeResponse.thingName());
                System.out.println("Thing ARN: " + describeResponse.thingArn());
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to describe Thing.");
                }
            }
        });

        future.join();
    }

    /**
     * Updates the shadow of an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     *
     * This method initiates an asynchronous request to update the shadow of an IoT Thing.
     * If the request is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void updateShadowThing(String thingName) {
        // Create Thing Shadow State Document.
        String stateDocument = "{\"state\":{\"reported\":{\"temperature\":25, \"humidity\":50}}}";
        SdkBytes data = SdkBytes.fromString(stateDocument, StandardCharsets.UTF_8);
        UpdateThingShadowRequest updateThingShadowRequest = UpdateThingShadowRequest.builder()
            .thingName(thingName)
            .payload(data)
            .build();

        CompletableFuture<UpdateThingShadowResponse> future = getAsyncDataPlaneClient().updateThingShadow(updateThingShadowRequest);
        future.whenComplete((updateResponse, ex) -> {
            if (updateResponse != null) {
                System.out.println("Thing Shadow updated successfully.");
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to update Thing Shadow.");
                }
            }
        });

        future.join();
    }

    /**
     * Describes the endpoint of the IoT service asynchronously.
     *
     * @return A CompletableFuture containing the full endpoint URL.
     *
     * This method initiates an asynchronous request to describe the endpoint of the IoT service.
     * If the request is successful, it prints and returns the full endpoint URL.
     * If an exception occurs, it prints the error message.
     */
    public String describeEndpoint() {
        CompletableFuture<DescribeEndpointResponse> future = getAsyncClient().describeEndpoint(DescribeEndpointRequest.builder().endpointType("iot:Data-ATS").build());
        final String[] result = {null};

        future.whenComplete((endpointResponse, ex) -> {
            if (endpointResponse != null) {
                String endpointUrl = endpointResponse.endpointAddress();
                String exString = getValue(endpointUrl);
                String fullEndpoint = "https://" + exString + "-ats.iot.us-east-1.amazonaws.com";

                System.out.println("Full Endpoint URL: " + fullEndpoint);
                result[0] = fullEndpoint;
            } else {
                Throwable cause = (ex instanceof CompletionException) ? ex.getCause() : ex;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + cause.getMessage());
                }
            }
        });

        future.join();
        return result[0];
    }

    /**
     * Extracts a specific value from the endpoint URL.
     *
     * @param input The endpoint URL to process.
     * @return The extracted value from the endpoint URL.
     */
    private static String getValue(String input) {
        // Define a regular expression pattern for extracting the subdomain.
        Pattern pattern = Pattern.compile("^(.*?)\\.iot\\.us-east-1\\.amazonaws\\.com");

        // Match the pattern against the input string.
        Matcher matcher = pattern.matcher(input);

        // Check if a match is found.
        if (matcher.find()) {
            // Extract the subdomain from the first capturing group.
            String subdomain = matcher.group(1);
            System.out.println("Extracted subdomain: " + subdomain);
            return subdomain ;
        } else {
            System.out.println("No match found");
        }
        return "" ;
    }

    /**
     * Lists all certificates asynchronously.
     *
     * This method initiates an asynchronous request to list all certificates.
     * If the request is successful, it prints the certificate IDs and ARNs.
     * If an exception occurs, it prints the error message.
     */
    public void listCertificates() {
        CompletableFuture<ListCertificatesResponse> future = getAsyncClient().listCertificates();
        future.whenComplete((response, ex) -> {
            if (response != null) {
                List<Certificate> certList = response.certificates();
                for (Certificate cert : certList) {
                    System.out.println("Cert id: " + cert.certificateId());
                    System.out.println("Cert Arn: " + cert.certificateArn());
                }
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to list certificates.");
                }
            }
        });

        future.join();
    }

    /**
     * Retrieves the payload of a Thing's shadow asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     *
     * This method initiates an asynchronous request to get the payload of a Thing's shadow.
     * If the request is successful, it prints the shadow data.
     * If an exception occurs, it prints the error message.
     */
    public void getPayload(String thingName) {
        GetThingShadowRequest getThingShadowRequest = GetThingShadowRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<GetThingShadowResponse> future = getAsyncDataPlaneClient().getThingShadow(getThingShadowRequest);
        future.whenComplete((getThingShadowResponse, ex) -> {
            if (getThingShadowResponse != null) {
                // Extracting payload from response.
                SdkBytes payload = getThingShadowResponse.payload();
                String payloadString = payload.asUtf8String();
                System.out.println("Received Shadow Data: " + payloadString);
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to get Thing Shadow payload.");
                }
            }
        });

        future.join();
    }

    /**
     * Creates an IoT rule asynchronously.
     *
     * @param roleARN The ARN of the IAM role that grants access to the rule's actions.
     * @param ruleName The name of the IoT rule.
     * @param action The ARN of the action to perform when the rule is triggered.
     *
     * This method initiates an asynchronous request to create an IoT rule.
     * If the request is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void createIoTRule(String roleARN, String ruleName, String action) {
        String sql = "SELECT * FROM '" + TOPIC + "'";
        SnsAction action1 = SnsAction.builder()
            .targetArn(action)
            .roleArn(roleARN)
            .build();

        // Create the action.
        Action myAction = Action.builder()
            .sns(action1)
            .build();

        // Create the topic rule payload.
        TopicRulePayload topicRulePayload = TopicRulePayload.builder()
            .sql(sql)
            .actions(myAction)
            .build();

        // Create the topic rule request.
        CreateTopicRuleRequest topicRuleRequest = CreateTopicRuleRequest.builder()
            .ruleName(ruleName)
            .topicRulePayload(topicRulePayload)
            .build();

        CompletableFuture<CreateTopicRuleResponse> future = getAsyncClient().createTopicRule(topicRuleRequest);
        future.whenComplete((response, ex) -> {
            if (response != null) {
                System.out.println("IoT Rule created successfully.");
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to create IoT Rule.");
                }
            }
        });

        future.join();
    }

    /**
     * Lists IoT rules asynchronously.
     *
     * This method initiates an asynchronous request to list IoT rules.
     * If the request is successful, it prints the names and ARNs of the rules.
     * If an exception occurs, it prints the error message.
     */
    public void listIoTRules() {
        ListTopicRulesRequest listTopicRulesRequest = ListTopicRulesRequest.builder().build();
        CompletableFuture<ListTopicRulesResponse> future = getAsyncClient().listTopicRules(listTopicRulesRequest);
        future.whenComplete((listTopicRulesResponse, ex) -> {
            if (listTopicRulesResponse != null) {
                System.out.println("List of IoT Rules:");
                List<TopicRuleListItem> ruleList = listTopicRulesResponse.rules();
                for (TopicRuleListItem rule : ruleList) {
                    System.out.println("Rule Name: " + rule.ruleName());
                    System.out.println("Rule ARN: " + rule.ruleArn());
                    System.out.println("--------------");
                }
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to list IoT Rules.");
                }
            }
        });

        future.join();
    }

    /**
     * Searches for IoT Things asynchronously based on a query string.
     *
     * @param queryString The query string to search for Things.
     *
     * This method initiates an asynchronous request to search for IoT Things.
     * If the request is successful and Things are found, it prints their IDs.
     * If no Things are found, it prints a message indicating so.
     * If an exception occurs, it prints the error message.
     */
    public void searchThings(String queryString) {
        SearchIndexRequest searchIndexRequest = SearchIndexRequest.builder()
            .queryString(queryString)
            .build();

        CompletableFuture<SearchIndexResponse> future = getAsyncClient().searchIndex(searchIndexRequest);
        future.whenComplete((searchIndexResponse, ex) -> {
            if (searchIndexResponse != null) {
                // Process the result.
                if (searchIndexResponse.things().isEmpty()) {
                    System.out.println("No things found.");
                } else {
                    searchIndexResponse.things().forEach(thing -> System.out.println("Thing id found using search is " + thing.thingId()));
                }
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to search for IoT Things.");
                }
            }
        });

        future.join();
    }

    /**
     * Detaches a principal (certificate) from an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     * @param certificateArn The ARN of the certificate to detach.
     *
     * This method initiates an asynchronous request to detach a certificate from an IoT Thing.
     * If the detachment is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void detachThingPrincipal(String thingName, String certificateArn) {
        DetachThingPrincipalRequest thingPrincipalRequest = DetachThingPrincipalRequest.builder()
            .principal(certificateArn)
            .thingName(thingName)
            .build();

        CompletableFuture<DetachThingPrincipalResponse> future = getAsyncClient().detachThingPrincipal(thingPrincipalRequest);
        future.whenComplete((voidResult, ex) -> {
            if (ex == null) {
                System.out.println(certificateArn + " was successfully removed from " + thingName);
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + ex.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Deletes a certificate asynchronously.
     *
     * @param certificateArn The ARN of the certificate to delete.
     *
     * This method initiates an asynchronous request to delete a certificate.
     * If the deletion is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void deleteCertificate(String certificateArn) {
        DeleteCertificateRequest certificateProviderRequest = DeleteCertificateRequest.builder()
            .certificateId(extractCertificateId(certificateArn))
            .build();

        CompletableFuture<DeleteCertificateResponse> future = getAsyncClient().deleteCertificate(certificateProviderRequest);
        future.whenComplete((voidResult, ex) -> {
            if (ex == null) {
                System.out.println(certificateArn + " was successfully deleted.");
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + ex.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Deletes an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing to delete.
     *
     * This method initiates an asynchronous request to delete an IoT Thing.
     * If the deletion is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void deleteIoTThing(String thingName) {
        DeleteThingRequest deleteThingRequest = DeleteThingRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<DeleteThingResponse> future = getAsyncClient().deleteThing(deleteThingRequest);
        future.whenComplete((voidResult, ex) -> {
            if (ex == null) {
                System.out.println("Deleted Thing " + thingName);
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + ex.getMessage());
                }
            }
        });

        future.join();
    }

    // Get the cert Id  from the Cert ARN value.
    private String extractCertificateId(String certificateArn) {
        // Example ARN: arn:aws:iot:region:account-id:cert/certificate-id.
        String[] arnParts = certificateArn.split(":");
        String certificateIdPart = arnParts[arnParts.length - 1];
        return certificateIdPart.substring(certificateIdPart.lastIndexOf("/") + 1);
    }
}

    /**
     * Attaches a certificate to an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     * @param certificateArn The ARN of the certificate to attach.
     *
     * This method initiates an asynchronous request to attach a certificate to an IoT Thing.
     * If the request is successful, it prints a confirmation message and additional information about the Thing.
     * If an exception occurs, it prints the error message.
     */
    public void attachCertificateToThing(String thingName, String certificateArn) {
        AttachThingPrincipalRequest principalRequest = AttachThingPrincipalRequest.builder()
            .thingName(thingName)
            .principal(certificateArn)
            .build();

        CompletableFuture<AttachThingPrincipalResponse> future = getAsyncClient().attachThingPrincipal(principalRequest);
        future.whenComplete((attachResponse, ex) -> {
            if (attachResponse != null && attachResponse.sdkHttpResponse().isSuccessful()) {
                System.out.println("Certificate attached to Thing successfully.");

                // Print additional information about the Thing.
                describeThing(thingName);
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to attach certificate to Thing. HTTP Status Code: " +
                        attachResponse.sdkHttpResponse().statusCode());
                }
            }
        });

        future.join();
    }

    /**
     * Creates an IoT certificate asynchronously.
     *
     * @return The ARN of the created certificate.
     * <p>
     * This method initiates an asynchronous request to create an IoT certificate.
     * If the request is successful, it prints the certificate details and returns the certificate ARN.
     * If an exception occurs, it prints the error message.
     */
    public String createCertificate() {
        CompletableFuture<CreateKeysAndCertificateResponse> future = getAsyncClient().createKeysAndCertificate();
        final String[] certificateArn = {null};
        future.whenComplete((response, ex) -> {
            if (response != null) {
                String certificatePem = response.certificatePem();
                certificateArn[0] = response.certificateArn();

                // Print the details.
                System.out.println("\nCertificate:");
                System.out.println(certificatePem);
                System.out.println("\nCertificate ARN:");
                System.out.println(certificateArn[0]);

            } else {
                Throwable cause = (ex instanceof CompletionException) ? ex.getCause() : ex;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + cause.getMessage());
                }
            }
        });

        future.join();
        return certificateArn[0];
    }

    /**
     * Creates an IoT Thing with the specified name asynchronously.
     *
     * @param thingName The name of the IoT Thing to create.
     *
     * This method initiates an asynchronous request to create an IoT Thing with the specified name.
     * If the request is successful, it prints the name of the thing and its ARN value.
     * If an exception occurs, it prints the error message.
     */
    public void createIoTThing(String thingName) {
        CreateThingRequest createThingRequest = CreateThingRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<CreateThingResponse> future = getAsyncClient().createThing(createThingRequest);
        future.whenComplete((createThingResponse, ex) -> {
            if (createThingResponse != null) {
                System.out.println(thingName + " was successfully created. The ARN value is " + createThingResponse.thingArn());
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + cause.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Creates an IoT rule asynchronously.
     *
     * @param roleARN The ARN of the IAM role that grants access to the rule's actions.
     * @param ruleName The name of the IoT rule.
     * @param action The ARN of the action to perform when the rule is triggered.
     *
     * This method initiates an asynchronous request to create an IoT rule.
     * If the request is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void createIoTRule(String roleARN, String ruleName, String action) {
        String sql = "SELECT * FROM '" + TOPIC + "'";
        SnsAction action1 = SnsAction.builder()
            .targetArn(action)
            .roleArn(roleARN)
            .build();

        // Create the action.
        Action myAction = Action.builder()
            .sns(action1)
            .build();

        // Create the topic rule payload.
        TopicRulePayload topicRulePayload = TopicRulePayload.builder()
            .sql(sql)
            .actions(myAction)
            .build();

        // Create the topic rule request.
        CreateTopicRuleRequest topicRuleRequest = CreateTopicRuleRequest.builder()
            .ruleName(ruleName)
            .topicRulePayload(topicRulePayload)
            .build();

        CompletableFuture<CreateTopicRuleResponse> future = getAsyncClient().createTopicRule(topicRuleRequest);
        future.whenComplete((response, ex) -> {
            if (response != null) {
                System.out.println("IoT Rule created successfully.");
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to create IoT Rule.");
                }
            }
        });

        future.join();
    }

    /**
     * Deletes a certificate asynchronously.
     *
     * @param certificateArn The ARN of the certificate to delete.
     *
     * This method initiates an asynchronous request to delete a certificate.
     * If the deletion is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void deleteCertificate(String certificateArn) {
        DeleteCertificateRequest certificateProviderRequest = DeleteCertificateRequest.builder()
            .certificateId(extractCertificateId(certificateArn))
            .build();

        CompletableFuture<DeleteCertificateResponse> future = getAsyncClient().deleteCertificate(certificateProviderRequest);
        future.whenComplete((voidResult, ex) -> {
            if (ex == null) {
                System.out.println(certificateArn + " was successfully deleted.");
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + ex.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Deletes an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing to delete.
     *
     * This method initiates an asynchronous request to delete an IoT Thing.
     * If the deletion is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void deleteIoTThing(String thingName) {
        DeleteThingRequest deleteThingRequest = DeleteThingRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<DeleteThingResponse> future = getAsyncClient().deleteThing(deleteThingRequest);
        future.whenComplete((voidResult, ex) -> {
            if (ex == null) {
                System.out.println("Deleted Thing " + thingName);
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + ex.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Describes the endpoint of the IoT service asynchronously.
     *
     * @return A CompletableFuture containing the full endpoint URL.
     *
     * This method initiates an asynchronous request to describe the endpoint of the IoT service.
     * If the request is successful, it prints and returns the full endpoint URL.
     * If an exception occurs, it prints the error message.
     */
    public String describeEndpoint() {
        CompletableFuture<DescribeEndpointResponse> future = getAsyncClient().describeEndpoint(DescribeEndpointRequest.builder().endpointType("iot:Data-ATS").build());
        final String[] result = {null};

        future.whenComplete((endpointResponse, ex) -> {
            if (endpointResponse != null) {
                String endpointUrl = endpointResponse.endpointAddress();
                String exString = getValue(endpointUrl);
                String fullEndpoint = "https://" + exString + "-ats.iot.us-east-1.amazonaws.com";

                System.out.println("Full Endpoint URL: " + fullEndpoint);
                result[0] = fullEndpoint;
            } else {
                Throwable cause = (ex instanceof CompletionException) ? ex.getCause() : ex;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + cause.getMessage());
                }
            }
        });

        future.join();
        return result[0];
    }

    /**
     * Describes an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     *
     * This method initiates an asynchronous request to describe an IoT Thing.
     * If the request is successful, it prints the Thing details.
     * If an exception occurs, it prints the error message.
     */
    private void describeThing(String thingName) {
        DescribeThingRequest thingRequest = DescribeThingRequest.builder()
            .thingName(thingName)
            .build();

        CompletableFuture<DescribeThingResponse> future = getAsyncClient().describeThing(thingRequest);
        future.whenComplete((describeResponse, ex) -> {
            if (describeResponse != null) {
                System.out.println("Thing Details:");
                System.out.println("Thing Name: " + describeResponse.thingName());
                System.out.println("Thing ARN: " + describeResponse.thingArn());
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to describe Thing.");
                }
            }
        });

        future.join();
    }

    /**
     * Detaches a principal (certificate) from an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     * @param certificateArn The ARN of the certificate to detach.
     *
     * This method initiates an asynchronous request to detach a certificate from an IoT Thing.
     * If the detachment is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void detachThingPrincipal(String thingName, String certificateArn) {
        DetachThingPrincipalRequest thingPrincipalRequest = DetachThingPrincipalRequest.builder()
            .principal(certificateArn)
            .thingName(thingName)
            .build();

        CompletableFuture<DetachThingPrincipalResponse> future = getAsyncClient().detachThingPrincipal(thingPrincipalRequest);
        future.whenComplete((voidResult, ex) -> {
            if (ex == null) {
                System.out.println(certificateArn + " was successfully removed from " + thingName);
            } else {
                Throwable cause = ex.getCause();
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else {
                    System.err.println("Unexpected error: " + ex.getMessage());
                }
            }
        });

        future.join();
    }

    /**
     * Lists all certificates asynchronously.
     *
     * This method initiates an asynchronous request to list all certificates.
     * If the request is successful, it prints the certificate IDs and ARNs.
     * If an exception occurs, it prints the error message.
     */
    public void listCertificates() {
        CompletableFuture<ListCertificatesResponse> future = getAsyncClient().listCertificates();
        future.whenComplete((response, ex) -> {
            if (response != null) {
                List<Certificate> certList = response.certificates();
                for (Certificate cert : certList) {
                    System.out.println("Cert id: " + cert.certificateId());
                    System.out.println("Cert Arn: " + cert.certificateArn());
                }
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to list certificates.");
                }
            }
        });

        future.join();
    }

    /**
     * Searches for IoT Things asynchronously based on a query string.
     *
     * @param queryString The query string to search for Things.
     *
     * This method initiates an asynchronous request to search for IoT Things.
     * If the request is successful and Things are found, it prints their IDs.
     * If no Things are found, it prints a message indicating so.
     * If an exception occurs, it prints the error message.
     */
    public void searchThings(String queryString) {
        SearchIndexRequest searchIndexRequest = SearchIndexRequest.builder()
            .queryString(queryString)
            .build();

        CompletableFuture<SearchIndexResponse> future = getAsyncClient().searchIndex(searchIndexRequest);
        future.whenComplete((searchIndexResponse, ex) -> {
            if (searchIndexResponse != null) {
                // Process the result.
                if (searchIndexResponse.things().isEmpty()) {
                    System.out.println("No things found.");
                } else {
                    searchIndexResponse.things().forEach(thing -> System.out.println("Thing id found using search is " + thing.thingId()));
                }
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to search for IoT Things.");
                }
            }
        });

        future.join();
    }

    /**
     * Updates the shadow of an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     *
     * This method initiates an asynchronous request to update the shadow of an IoT Thing.
     * If the request is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void updateShadowThing(String thingName) {
        // Create Thing Shadow State Document.
        String stateDocument = "{\"state\":{\"reported\":{\"temperature\":25, \"humidity\":50}}}";
        SdkBytes data = SdkBytes.fromString(stateDocument, StandardCharsets.UTF_8);
        UpdateThingShadowRequest updateThingShadowRequest = UpdateThingShadowRequest.builder()
            .thingName(thingName)
            .payload(data)
            .build();

        CompletableFuture<UpdateThingShadowResponse> future = getAsyncDataPlaneClient().updateThingShadow(updateThingShadowRequest);
        future.whenComplete((updateResponse, ex) -> {
            if (updateResponse != null) {
                System.out.println("Thing Shadow updated successfully.");
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to update Thing Shadow.");
                }
            }
        });

        future.join();
    }