There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Hello CloudWatch
<a name="cloudwatch_example_cloudwatch_Hello_section"></a>

The following code examples show how to get started using CloudWatch.

------
#### [ .NET ]

**SDK for .NET (v4)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/CloudWatch#code-examples). 

```
using Amazon.CloudWatch;
using Amazon.CloudWatch.Model;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace CloudWatchActions;

public static class HelloCloudWatch
{
    static async Task Main(string[] args)
    {
        // Use the AWS .NET Core Setup package to set up dependency injection for the Amazon CloudWatch service.
        // Use your AWS profile name, or leave it blank to use the default profile.
        using var host = Host.CreateDefaultBuilder(args)
            .ConfigureServices((_, services) =>
                services.AddAWSService<IAmazonCloudWatch>()
            ).Build();

        // Now the client is available for injection.
        var cloudWatchClient = host.Services.GetRequiredService<IAmazonCloudWatch>();

        // You can use await and any of the async methods to get a response.
        var metricNamespace = "AWS/Billing";
        var response = await cloudWatchClient.ListMetricsAsync(new ListMetricsRequest
        {
            Namespace = metricNamespace
        });
        Console.WriteLine($"Hello Amazon CloudWatch! Following are some metrics available in the {metricNamespace} namespace:");
        Console.WriteLine();
        if (response.Metrics != null)
        {
            foreach (var metric in response.Metrics.Take(5))
            {
                Console.WriteLine($"\tMetric: {metric.MetricName}");
                Console.WriteLine($"\tNamespace: {metric.Namespace}");
                Console.WriteLine(
                    $"\tDimensions: {string.Join(", ", metric.Dimensions.Select(m => $"{m.Name}:{m.Value}"))}");
                Console.WriteLine();
            }
        }
    }
}
```
+  For API details, see [ListMetrics](https://docs.aws.amazon.com/goto/DotNetSDKV4/monitoring-2010-08-01/ListMetrics) in *AWS SDK for .NET API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/cloudwatch#code-examples). 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatch.CloudWatchClient;
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException;
import software.amazon.awssdk.services.cloudwatch.model.ListMetricsRequest;
import software.amazon.awssdk.services.cloudwatch.paginators.ListMetricsIterable;

/**
 * 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
 */
public class HelloService {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                  <namespace>\s

                Where:
                  namespace - The namespace to filter against (for example, AWS/EC2).\s
                """;

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

        String namespace = args[0];
        Region region = Region.US_EAST_1;
        CloudWatchClient cw = CloudWatchClient.builder()
                .region(region)
                .build();

        listMets(cw, namespace);
        cw.close();
    }

    public static void listMets(CloudWatchClient cw, String namespace) {
        try {
            ListMetricsRequest request = ListMetricsRequest.builder()
                    .namespace(namespace)
                    .build();

            ListMetricsIterable listRes = cw.listMetricsPaginator(request);
            listRes.stream()
                    .flatMap(r -> r.metrics().stream())
                    .forEach(metrics -> System.out.println(" Retrieved metric is: " + metrics.metricName()));

        } catch (CloudWatchException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}
```
+  For API details, see [ListMetrics](https://docs.aws.amazon.com/goto/SdkForJavaV2/monitoring-2010-08-01/ListMetrics) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ Kotlin ]

**SDK for Kotlin**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/cloudwatch#code-examples). 

```
/**
Before running this Kotlin 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-kotlin/latest/developer-guide/setup.html
 */
suspend fun main(args: Array<String>) {
    val usage = """
        Usage:
           <namespace> 
        Where:
           namespace - The namespace to filter against (for example, AWS/EC2). 
    """

    if (args.size != 1) {
        println(usage)
        exitProcess(0)
    }

    val namespace = args[0]
    listAllMets(namespace)
}

suspend fun listAllMets(namespaceVal: String?) {
    val request =
        ListMetricsRequest {
            namespace = namespaceVal
        }

    CloudWatchClient.fromEnvironment { region = "us-east-1" }.use { cwClient ->
        cwClient
            .listMetricsPaginated(request)
            .transform { it.metrics?.forEach { obj -> emit(obj) } }
            .collect { obj ->
                println("Name is ${obj.metricName}")
                println("Namespace is ${obj.namespace}")
            }
    }
}
```
+  For API details, see [ListMetrics](https://sdk.amazonaws.com/kotlin/api/latest/index.html) in *AWS SDK for Kotlin API reference*. 

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