aws-sdk-java-v2-lambda git:20260323.300f036A

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---
name: aws-sdk-java-v2-lambda
description: Provides AWS Lambda patterns using AWS SDK for Java 2.x. Use when invoking Lambda functions, creating/updating functions, managing function configurations, working with Lambda layers, or integrating Lambda with Spring Boot applications.
allowed-tools: Read, Write, Edit, Bash, Glob, Grep
---

# 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 programmatically
- Creating or updating Lambda functions
- Managing Lambda function configurations
- Working with Lambda environment variables
- Managing Lambda layers and aliases
- Implementing asynchronous Lambda invocations
- Integrating Lambda with Spring Boot

## Quick Reference

| Operation | SDK Method | Use Case |
|-----------|------------|----------|
| **Invoke** | `invoke()` | Synchronous/async function invocation |
| **List Functions** | `listFunctions()` | Get all Lambda functions |
| **Get Config** | `getFunction()` | Retrieve function configuration |
| **Create Function** | `createFunction()` | Create new Lambda function |
| **Update Code** | `updateFunctionCode()` | Deploy new function code |
| **Update Config** | `updateFunctionConfiguration()` | Modify settings (timeout, memory, env vars) |
| **Delete Function** | `deleteFunction()` | Remove Lambda function |

## Instructions

### 1. Add Dependencies

Include Lambda SDK dependency in `pom.xml`:

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

See [client-setup.md](references/client-setup.md) for complete setup.

### 2. Create Client

Instantiate `LambdaClient` with proper configuration:

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

For async operations, use `LambdaAsyncClient`.

### 3. Invoke Lambda Function

Synchronous invocation:

```java
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](references/invocation-patterns.md) for patterns.

### 4. Handle Responses

Parse response payloads and check for errors:

```java
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:

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

lambdaClient.createFunction(createRequest);

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

lambdaClient.updateFunctionCode(updateCodeRequest);
```

See [function-management.md](references/function-management.md) for complete patterns.

### 6. Configure Environment

Set environment variables and concurrency limits:

```java
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:

```java
@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
    }
}
```

See [spring-boot-integration.md](references/spring-boot-integration.md) for complete integration.

### 8. Test Locally

Use mocks or LocalStack for development testing.

See [testing.md](references/testing.md) for testing patterns.

## Examples

### Basic Invocation

```java
public String invokeFunction(LambdaClient client, String functionName, String payload) {
    InvokeRequest request = InvokeRequest.builder()
        .functionName(functionName)
        .payload(SdkBytes.fromUtf8String(payload))
        .build();

    InvokeResponse response = client.invoke(request);

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

    return response.payload().asUtf8String();
}
```

### Async Invocation

```java
public void invokeAsync(LambdaClient client, String functionName, Map<String, Object> event) {
    String jsonPayload = new ObjectMapper().writeValueAsString(event);

    InvokeRequest request = InvokeRequest.builder()
        .functionName(functionName)
        .invocationType(InvocationType.EVENT)
        .payload(SdkBytes.fromUtf8String(jsonPayload))
        .build();

    client.invoke(request);
}
```

### Spring Boot Service

```java
@Service
public class LambdaService {
    private final LambdaClient lambdaClient;

    public UserResponse processUser(UserRequest request) {
        String payload = objectMapper.writeValueAsString(request);

        InvokeResponse response = lambdaClient.invoke(
            InvokeRequest.builder()
                .functionName("user-processor")
                .payload(SdkBytes.fromUtf8String(payload))
                .build()
        );

        return objectMapper.readValue(
            response.payload().asUtf8String(),
            UserResponse.class
        );
    }
}
```

See [examples.md](references/examples.md) for more examples.

## Best Practices

- **Reuse Lambda clients**: Create once and reuse across invocations
- **Set appropriate timeouts**: Match client timeout to Lambda function timeout
- **Use async invocation**: For fire-and-forget scenarios
- **Handle errors properly**: Check for function errors and status codes
- **Use environment variables**: For function configuration
- **Implement retry logic**: For transient failures with exponential backoff
- **Monitor invocations**: Use CloudWatch metrics and logs
- **Version functions**: Use aliases and versions for production
- **Use VPC**: For accessing resources in private subnets
- **Optimize payload size**: Keep payloads small for better performance

## Constraints and Warnings

- **Payload Size**: Limited to 6MB for sync, 256KB for async invocation
- **Timeout**: Maximum function timeout is 15 minutes
- **Memory**: Memory configuration affects CPU and network performance
- **Concurrency**: Account-level concurrency limits can cause throttling
- **Cold Starts**: New invocations may have delays for initialization
- **VPC**: VPC functions need proper security group and subnet configuration
- **Layers**: Lambda layers count towards deployment package size limit
- **Reserved Concurrency**: Prevents throttling but limits maximum scaling
- **Event Source Mappings**: Some event sources require special configuration
- **Cost**: Unexpected usage can lead to high bills; set budgets and alerts

## References

- **[client-setup.md](references/client-setup.md)** — Client configuration and setup
- **[invocation-patterns.md](references/invocation-patterns.md)** — Synchronous and async invocation patterns
- **[function-management.md](references/function-management.md)** — Create, update, delete functions
- **[spring-boot-integration.md](references/spring-boot-integration.md)** — Spring Boot configuration and services
- **[testing.md](references/testing.md)** — Unit and integration testing patterns
- **[examples.md](references/examples.md)** — Complete code examples and integration patterns
- **[official-documentation.md](references/official-documentation.md)** — AWS Lambda concepts and API reference

## Related Skills

- `aws-sdk-java-v2-core` — Core AWS SDK patterns and client configuration
- `spring-boot-dependency-injection` — Spring dependency injection best practices
- `unit-test-service-layer` — Service testing patterns with Mockito
- `spring-boot-actuator` — Production monitoring and health checks

## External Resources

- [Lambda Examples on GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda)
- [Lambda API Reference](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/lambda/package-summary.html)
- [AWS Lambda Developer Guide](https://docs.aws.amazon.com/lambda/latest/dg/welcome.html)