How to use Kiro for Java

Kiro provides powerful AI-assisted development capabilities for Java projects, helping you write, debug, and maintain Java code more efficiently.

Prerequisites

Before diving into Java development with Kiro, ensure you have:

• Java Development Kit (JDK): Install the latest LTS version (JDK 17 or newer recommended). We recommend Amazon Corretto for a free, production-ready distribution of OpenJDK.
• Build Tool: Maven or Gradle for dependency management and build automation.
• Git: For version control and collaboration.

Extensions

Kiro supports extensions from Open VSX that can enhance your Java development experience. Here are some helpful extensions you can install:

Core Extensions

• Extension Pack for Java: Popular extensions for Java development in Visual Studio Code. Includes Language Support for Java, Debugger for Java, Test Runner for Java, Maven for Java, Project Manager for Java, and IntelliCode.

Framework-Specific Extensions

• Spring Boot Extension Pack: A collection of extensions for Spring Boot development including Spring Boot Tools, Spring Initializr Java Support, and Spring Boot Dashboard.

Build Tool Extensions

• Gradle for Java: Manage Gradle projects, run Gradle tasks and provide better Gradle file authoring experience in Kiro.
• Maven for Java: Manage Maven projects, run Maven tasks and provide better Maven project authoring experience in Kiro.

Additional Utilities

• Markdown Preview Enhanced: For viewing and editing markdown files with live preview.

You can install these extensions in Kiro by using the Extensions panel and searching for the extension names listed above.

Working With Your Environment

With Kiro, you can leverage the chat capabilities to setup a new project or work on an existing one.

Project Configuration and Structure

Kiro can help you set up and maintain configuration files for your Java projects, and organize your project following Java best practices:

• Initialize configuration files: Ask Kiro to initialize default configuration files based on the project.
• Create project structure: Ask Kiro to create the structure of your project based on needs and best practices.
• Environment setup: Get help configuring your Java development environment.

Example prompts:

"Create a new Maven project for a Spring Boot application"
"Set up a Gradle build file with JUnit 5 and Mockito dependencies"
"Configure a multi-module Maven project structure"
"Help me install and configure the latest JDK for my operating system"
"Set up a Spring Boot project with proper layered architecture"
"Create a pom.xml with Spring Security and JPA dependencies"

Code Analysis and Refactoring

Kiro can analyze your Java code to identify issues and suggest improvements:

Key Features

• Code Quality Analysis: Ask Kiro to review your code for potential bugs, performance issues, or style issues.
• Refactoring Assistance: Get help extracting methods, renaming variables, or restructuring code.
• Design Pattern Implementation: Kiro can help implement common design patterns in your Java code.

Example prompts:

"Analyze this method for potential bugs or performance issues"
"Refactor this code to use the Builder pattern"
"Convert this imperative code to use Java Streams"
"Help me implement the Strategy pattern for this business logic"
"Suggest improvements for this class structure"

Debugging Assistance

When you encounter errors in your Java code:

Debugging Capabilities

• Error Explanation: Kiro can explain cryptic error messages in plain language
• Solution Suggestions: Get actionable fixes for common errors
• Runtime Debugging: Kiro can help set up debugging configurations

Examples:

"Explain this NullPointerException in my code"
"Help me debug this ConcurrentModificationException"
"Analyze this stack trace and suggest a fix"
"Why am I getting a ClassNotFoundException?"
"Help me understand this OutOfMemoryError"

Steering

Steering allows you to provide Kiro with project specific context and guidelines. Kiro can generate steering files which you can refine:

Core Steering Files

• Product brief (product.md) - Contains information about the product, its purpose, and key features
• Technical Stack (tech.md) - Details the technologies, frameworks, and development guidelines
• Project Structure (structure.md) - Provides information about how the project is organized

Creating Custom Steering Files

To add new steering documents to your project:

1. Navigate to the Kiro view in the sidebar.
2. In the Agent Steering section, choose the + button to create a new steering file.
3. Enter a name for your file with a descriptive title.
4. Add your custom steering content following markdown conventions.

Custom steering files are stored in the .kiro/steering/ directory and are automatically recognized by Kiro during interactions.

Project-Specific Conventions

Create a java-conventions.md steering file to define your team's specific practices and architectural decisions:

# Java Project Conventions

## Architecture Patterns
- Use hexagonal architecture for complex domains
- Implement CQRS for read/write separation when needed
- Apply Domain-Driven Design principles for business logic

## Testing Strategy
- Write unit tests for all business logic
- Use TestContainers for integration tests
- Maintain 80% code coverage minimum
- Follow the AAA pattern (Arrange, Act, Assert)

## Error Handling
- Use custom exceptions for business logic errors
- Implement global exception handlers with @ControllerAdvice
- Log errors with correlation IDs for traceability
- Return consistent error response formats

## Performance Guidelines
- Use connection pooling for database access
- Implement caching strategies for frequently accessed data
- Use async processing for long-running operations
- Monitor and optimize database queries

Framework Specific Guidelines

For Spring Boot projects, create a spring-boot-patterns.md steering file:

# Spring Boot Development Guidelines

## Component Structure
- Use @RestController for REST endpoints
- Use @Service for business logic
- Use @Repository for data access
- Use @Component for other beans

## Dependency Injection
- Prefer constructor injection over field injection
- Use final fields for injected dependencies
- Avoid circular dependencies

## API Design
- Follow REST principles for endpoint design
- Use appropriate HTTP methods (GET, POST, PUT, DELETE)
- Return appropriate HTTP status codes
- Use DTOs for request/response objects

## Configuration Management
- Use @ConfigurationProperties for complex configurations
- Externalize configuration using application.yml or application.properties
- Use profiles for environment-specific settings

Agent Hooks

Kiro's Agent Hooks can automate common Java development tasks. For example, you can create hooks that:

• Automatically generate JUnit tests when you save a Java file
• Run code quality checks with Checkstyle or SpotBugs
• Check for outdated Maven or Gradle dependencies
• Generate or update JavaDoc comments for public methods
• Validate Spring Boot configuration files
• Format code with Google Java Format or similar tools
• Run static analysis tools like PMD or FindBugs
• Update version numbers in build files
• Generate API documentation from annotations

MCP Servers

Kiro's support for Model Context Protocol (MCP) servers enhance your Java development experience by providing specialized tools and capabilities.

Maven MCP Server

The Maven MCP server allows you to manage Maven projects directly within Kiro:

{
  "mcpServers": {
    "maven": {
      "command": "uvx",
      "args": ["maven-mcp-server@latest"]
    }
  }
}

With this server configured, you can:

• Run Maven commands with Kiro
• Get AI powered explanations for build issues
• Manage dependencies and project configuration
• Analyze dependency conflicts
• Generate project reports

Example usage:

"Run Maven tests for my project"
"Add Spring Boot starter dependencies to my pom.xml"
"Check for dependency vulnerabilities"
"Generate a dependency tree for my project"
"Update all dependencies to their latest versions"

Additional Useful MCP Servers

Explore more MCP servers in the AWS MCP Servers and Awesome MCP Servers collection for enhanced functionality like:

• Database connectivity and management
• Cloud service integration
• Code quality analysis
• Performance monitoring

Debugging Issues

When you encounter issues, Kiro can help diagnose and fix them:

Debugging Methods

• Inline Chat: Type Cmd/Ctrl + I to open the inline chat.

  • Ask Kiro to explain specific errors or suggest fixes for the current code.

• Add to Chat: Type Cmd/Ctrl + L to add the current file to the chat.

  • Ask Kiro to analyze the entire file for potential issues or improvements.

• Quick Fix: Hover on an error or warning, then select Quick fix and Ask Kiro.

  • Kiro will automatically add the code to the chat and start debugging.

Common Debugging Scenarios

Compilation Errors

"Why won't my code compile? Here's the error message..."
"Help me resolve this import conflict"
"Explain this generic type error"

Runtime Issues

"My application crashes on startup, here's the stack trace..."
"Help me debug this memory leak"
"Why is my Spring Boot application not starting?"

Performance Problems

"My application is running slowly, can you help optimize it?"
"Analyze this method for performance bottlenecks"
"Help me understand why my database queries are slow"

Best Practices for Using Kiro with Java

Effective Prompting

• Be specific about your requirements and constraints
• Provide context about your project structure and technologies
• Include relevant code snippets when asking for help
• Specify your Java version and framework versions

Code Quality

• Ask Kiro to review code for best practices
• Request explanations for complex algorithms or patterns
• Get suggestions for improving code readability and maintainability
• Validate architectural decisions with Kiro

Learning and Development

• Use Kiro to understand new Java features and APIs
• Ask for explanations of complex concepts
• Request examples of design pattern implementations
• Get help with testing strategies and frameworks

Resources

• Java Documentation
• Spring Framework Documentation
• Spring Boot Documentation
• Maven Documentation
• Gradle Documentation
• JUnit 5 Documentation
• Mockito Documentation

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By following this guide, you'll be able to leverage Kiro's AI-powered capabilities to enhance your Java development workflow, improve code quality, and solve problems more efficiently.