Boot Usage Spring Boot Starter

A Spring Boot starter that provides runtime analysis of starter usage in your application. It helps you identify:

• Used starters: Starters with auto-configurations that are actively contributing beans
• Unused starters: Starters included in your dependencies but not contributing any beans
• Indeterminate starters: Starters whose usage status cannot be definitively determined

This is invaluable for optimizing your application's dependencies and reducing bloat.

Features

• /actuator/bootusage - Actuator endpoint for runtime usage analysis
• Starter Detection - Automatically discovers Spring Boot starters on the classpath
• Auto-Configuration Analysis - Tracks which auto-configurations are active and contributing beans
• Bean Origin Tracking - Identifies which starters contributed which beans
• Usage Policies - Define custom policies to enforce starter usage rules (SPI)
• Multiple Output Formats - JSON endpoint response or Markdown summary files
• Caching - Configurable result caching for performance

Quick Start

Maven

<dependency>
    <groupId>io.github.dhruv1503</groupId>
    <artifactId>boot-usage-spring-boot-starter</artifactId>
    <version>1.0.3</version>
</dependency>

Gradle

implementation 'io.github.dhruv1503:boot-usage-spring-boot-starter:1.0.3'

Usage

Once added to your project, the starter automatically registers an actuator endpoint.

Accessing the Endpoint

# Get usage analysis
curl http://localhost:8080/actuator/bootusage

# Force cache refresh
curl http://localhost:8080/actuator/bootusage?force=true

Sample Response

{
  "usedStarters": [
    {
      "name": "spring-boot-starter-web",
      "groupId": "org.springframework.boot",
      "artifactId": "spring-boot-starter-web",
      "version": "3.3.5",
      "status": "USED",
      "category": "web"
    }
  ],
  "unusedStarters": [
    {
      "name": "spring-boot-starter-data-redis",
      "groupId": "org.springframework.boot",
      "artifactId": "spring-boot-starter-data-redis",
      "version": "3.3.5",
      "status": "UNUSED",
      "category": "data"
    }
  ],
  "indeterminateStarters": [],
  "matchedAutoConfigCount": 45,
  "excludedAutoConfigCount": 12
}

Configuration

Property	Type	Default	Description
management.endpoint.bootusage.enabled	boolean	true	Enable/disable the bootusage endpoint
spring.boot.usage.enabled	boolean	true	Enable/disable usage analysis
spring.boot.usage.cache-ttl	long	60000	Cache TTL in milliseconds
spring.boot.usage.include-origins	boolean	false	Include bean origin information
spring.boot.usage.include-confidence	boolean	false	Include confidence scores
spring.boot.usage.detect-unused-jars	boolean	false	Detect unused JAR files
spring.boot.usage.markdown-summary	boolean	false	Generate Markdown summary file
spring.boot.usage.output-dir	String	null	Directory for output files
spring.boot.usage.policies-fail-on-violation	boolean	false	Fail startup on policy violations

Example Configuration

management:
  endpoint:
    bootusage:
      enabled: true

spring:
  boot:
    usage:
      enabled: true
      cache-ttl: 120000
      include-origins: true
      detect-unused-jars: true
      policies-fail-on-violation: false

Usage Policies (SPI)

You can define custom policies to enforce starter usage rules. Implement the UsagePolicy interface:

import io.github.dhruv1503.bootusage.autoconfigure.UsagePolicy;
import io.github.dhruv1503.bootusage.autoconfigure.StarterUsageAnalyzer.StarterAnalysisResult;

public class NoUnusedStartersPolicy implements UsagePolicy {

    @Override
    public String getName() {
        return "no-unused-starters";
    }

    @Override
    public String getDescription() {
        return "Ensures no unused starters are present in the application";
    }

    @Override
    public PolicyResult evaluate(StarterAnalysisResult result) {
        if (result.unusedStarters().isEmpty()) {
            return PolicyResult.passed("No unused starters detected");
        }
        return PolicyResult.failed("Found " + result.unusedStarters().size() + 
            " unused starters: " + result.unusedStarters());
    }
}

Register your policy via Spring's META-INF/spring.factories or as a bean:

@Bean
public UsagePolicy noUnusedStartersPolicy() {
    return new NoUnusedStartersPolicy();
}

When spring.boot.usage.policies-fail-on-violation=true, any policy violation will cause application startup to fail.

Requirements

• Java 17 or later
• Spring Boot 3.2.0 or later

Building from Source

./gradlew clean build

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Acknowledgments

This project was inspired by discussions in Spring Boot PR #47023.

Author

• Dhruv Rastogi - dhruv-15-03