AWS SDK for Java 2.x - AWS Lambda

Overview

AWS Lambda is a compute service that runs code without managing servers. Use this skill to implement AWS Lambda operations using AWS SDK for Java 2.x in applications and services.

When to Use

• Invoking Lambda functions from Java applications
• Deploying and updating Lambda functions via SDK
• Managing function configurations and layers
• Integrating Lambda with Spring Boot applications

Quick Reference

Instructions

1. Add Dependencies

Include Lambda SDK dependency in pom.xml:

<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>lambda</artifactId>
</dependency>

See client-setup.md for complete setup.

2. Create Client

Instantiate LambdaClient with proper configuration:

LambdaClient lambdaClient = LambdaClient.builder()
    .region(Region.US_EAST_1)
    .build();

For async operations, use LambdaAsyncClient.

3. Invoke Lambda Function

Synchronous invocation:

InvokeRequest request = InvokeRequest.builder()
    .functionName("my-function")
    .payload(SdkBytes.fromUtf8String(payload))
    .build();

InvokeResponse response = lambdaClient.invoke(request);

return response.payload().asUtf8String();

See invocation-patterns.md for patterns.

4. Handle Responses

Parse response payloads and check for errors:

if (response.functionError() != null) {
    throw new LambdaInvocationException("Lambda error: " + response.functionError());
}

String result = response.payload().asUtf8String();

5. Manage Functions

Create, update, or delete Lambda functions:

// Create
CreateFunctionRequest createRequest = CreateFunctionRequest.builder()
    .functionName("my-function")
    .runtime(Runtime.JAVA17)
    .role(roleArn)
    .code(code)
    .build();

lambdaClient.createFunction(createRequest);

// Verify function is active before proceeding
GetFunctionRequest getRequest = GetFunctionRequest.builder()
    .functionName("my-function")
    .build();
GetFunctionResponse getResponse = lambdaClient.getFunction(getRequest);
if (!"Active".equals(getResponse.configuration().state())) {
    throw new IllegalStateException("Function not active: " + getResponse.configuration().stateReason());
}

// Update code
UpdateFunctionCodeRequest updateCodeRequest = UpdateFunctionCodeRequest.builder()
    .functionName("my-function")
    .zipFile(SdkBytes.fromByteArray(zipBytes))
    .build();

lambdaClient.updateFunctionCode(updateCodeRequest);

// Wait for deployment to complete
Waiter<GetFunctionConfigurationRequest> waiter = lambdaClient.waiter();
waiter.waitUntilFunctionUpdatedActive(GetFunctionConfigurationRequest.builder()
    .functionName("my-function")
    .build());

See function-management.md for complete patterns.

6. Configure Environment

Set environment variables and concurrency limits:

Environment env = Environment.builder()
    .variables(Map.of(
        "DB_URL", "jdbc:postgresql://db",
        "LOG_LEVEL", "INFO"
    ))
    .build();

UpdateFunctionConfigurationRequest configRequest = UpdateFunctionConfigurationRequest.builder()
    .functionName("my-function")
    .environment(env)
    .timeout(60)
    .memorySize(512)
    .build();

lambdaClient.updateFunctionConfiguration(configRequest);

7. Integrate with Spring Boot

Configure Lambda beans and services:

@Configuration
public class LambdaConfiguration {
    @Bean
    public LambdaClient lambdaClient() {
        return LambdaClient.builder()
            .region(Region.US_EAST_1)
            .build();
    }
}

@Service
public class LambdaInvokerService {
    public <T, R> R invoke(String functionName, T request, Class<R> responseType) {
        // Implementation
    }