CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository. 必须用中文回复我

Project Overview

tianai-captcha (天爱验证码/TAC) is a Java-based behavioral CAPTCHA library supporting multiple verification types:

• SLIDER: Slide-to-fit puzzle captcha
• ROTATE: Rotation verification captcha
• CONCAT: Slide-to-restore captcha
• WORD_IMAGE_CLICK: Text-click verification captcha

The project is a multi-module Maven project with Java 8 compatibility.

Build Commands

# Build the entire project (skips tests by default)
mvn clean install

# Build without skipping tests
mvn clean install -DskipTests=false

# Build specific module
cd tianai-captcha
mvn clean install

# Package for deployment
mvn clean package

# Generate javadoc
mvn javadoc:javadoc

Testing

# Run all tests
mvn test

# Run tests for specific module
cd tianai-captcha
mvn test

# Run a specific test class
mvn test -Dtest=TACBuilderTest

# Run a specific test method
mvn test -Dtest=TACBuilderTest#testMethod

Project Structure

Modules

1. tianai-captcha (core module)
   • Core captcha generation and validation logic
   • Generator implementations for each captcha type
   • Resource management system
   • Cache and storage abstractions
2. tianai-captcha-springboot-starter
   • Spring Boot auto-configuration
   • Redis integration support
   • Configuration properties binding
3. tianai-captcha-solon-plugin
   • Solon framework integration
4. tianai-captcha-web-sdk
   • Frontend JavaScript SDK

Core Architecture

Key Components

ImageCaptchaApplication (cloud.tianai.captcha.application.ImageCaptchaApplication)

• Main entry point for captcha operations
• Handles captcha generation via generateCaptcha(type)
• Handles validation via matching(id, matchParam)
• Manages lifecycle of generators, validators, and cache

TACBuilder (cloud.tianai.captcha.application.TACBuilder)

• Builder pattern for constructing ImageCaptchaApplication
• Fluent API for configuration
• Key methods:
  • addDefaultTemplate(): Load built-in templates
  • addResource(type, resource): Add background images
  • addTemplate(type, resourceMap): Add custom templates
  • addFont(resource): Add fonts for WORD_IMAGE_CLICK
  • cached(size, waitTime, period, expireTime): Enable pre-generation cache
  • setCacheStore(store): Set cache implementation (local or distributed)
  • setResourceStore(store): Set resource storage
  • setTransform(transform): Set image transformation (default: Base64)

Generator Layer

MultiImageCaptchaGenerator (cloud.tianai.captcha.generator.impl.MultiImageCaptchaGenerator)

• Delegates to specific generators based on captcha type
• Manages resource loading and image transformation

Specific Generators:

• StandardSliderImageCaptchaGenerator: Generates slider puzzles
• StandardRotateImageCaptchaGenerator: Generates rotation captchas
• StandardConcatImageCaptchaGenerator: Generates slide-to-restore captchas
• StandardWordClickImageCaptchaGenerator: Generates text-click captchas

CacheImageCaptchaGenerator (cloud.tianai.captcha.generator.impl.CacheImageCaptchaGenerator)

• Wrapper that pre-generates captchas for improved performance
• Configurable cache size and refresh intervals

Validator Layer

ImageCaptchaValidator (cloud.tianai.captcha.validator.ImageCaptchaValidator)

• Interface for captcha validation logic
• Default implementation: SimpleImageCaptchaValidator

BasicCaptchaTrackValidator (cloud.tianai.captcha.validator.impl.BasicCaptchaTrackValidator)

• Validates mouse/touch track data
• Checks for suspicious behavior patterns

Resource Management

ResourceStore (cloud.tianai.captcha.resource.ResourceStore)

• Abstraction for storing captcha resources (images, templates)
• Implementations:
  • LocalMemoryResourceStore: In-memory storage
  • Custom implementations for distributed scenarios

ImageCaptchaResourceManager (cloud.tianai.captcha.resource.ImageCaptchaResourceManager)

• Manages resource loading and retrieval
• Default implementation: DefaultImageCaptchaResourceManager

Resource (cloud.tianai.captcha.resource.common.model.dto.Resource)

• Represents a resource with type and location
• Types: "classpath", "file", "url"

Cache Layer

CacheStore (cloud.tianai.captcha.cache.CacheStore)

• Abstraction for caching captcha data
• Implementations:
  • LocalCacheStore: Local in-memory cache
  • Redis-based implementation in Spring Boot starter

Image Transformation

ImageTransform (cloud.tianai.captcha.generator.ImageTransform)

• Converts generated images to desired format
• Default: Base64ImageTransform (JPG for background, PNG for template)

Configuration

Non-Spring Projects

Use TACBuilder to configure:

ImageCaptchaApplication app = TACBuilder.builder()
    .addDefaultTemplate()
    .addResource("SLIDER", new Resource("classpath", "path/to/image.jpg"))
    .cached(20, 5000, 2000, 120000L)
    .build();

Spring Boot Projects

Configure via application.yml:

captcha:
  prefix: captcha                    # Cache key prefix
  expire:
    default: 120000                  # Default expiration (ms)
    WORD_IMAGE_CLICK: 180000        # Type-specific expiration
  init-default-resource: false       # Load built-in resources
  local-cache-enabled: true          # Enable pre-generation cache
  local-cache-size: 20              # Cache size
  local-cache-wait-time: 5000       # Wait time on cache miss (ms)
  local-cache-period: 2000          # Cache refresh interval (ms)
  font-path:                        # Font files for WORD_IMAGE_CLICK
    - classpath:font/simhei.ttf

Important Constants

CaptchaTypeConstant (cloud.tianai.captcha.common.constant.CaptchaTypeConstant)

• SLIDER: Slide-to-fit captcha
• ROTATE: Rotation captcha
• CONCAT: Slide-to-restore captcha
• WORD_IMAGE_CLICK: Text-click captcha

ParamKeyEnum (cloud.tianai.captcha.generator.common.model.dto.ParamKeyEnum)

• TOLERANT: Configurable tolerance value for validation (added in recent commit)

Key Data Flow

Generation Flow

1. Client calls ImageCaptchaApplication.generateCaptcha(type)
2. MultiImageCaptchaGenerator selects appropriate generator
3. Generator loads resources via ImageCaptchaResourceManager
4. Generator creates captcha with random parameters
5. ImageTransform converts images to Base64 (or custom format)
6. Captcha data cached in CacheStore with unique ID
7. Returns ImageCaptchaVO with ID and image data

Validation Flow

1. Client submits ID and track data via matching(id, matchParam)
2. Application retrieves cached captcha data by ID
3. ImageCaptchaValidator validates track against expected answer
4. BasicCaptchaTrackValidator checks track behavior patterns
5. Returns ApiResponse with success/failure status

Extension Points

• Custom Generators: Implement ImageCaptchaGenerator interface
• Custom Validators: Implement ImageCaptchaValidator interface
• Custom Cache: Implement CacheStore (e.g., Redis, Memcached)
• Custom Resources: Implement ResourceStore for centralized resource management
• Custom Transform: Implement ImageTransform for different image formats
• Interceptors: Implement CaptchaInterceptor for pre/post processing

Recent Changes

• Added support for Spring Boot 4 (commit: db0603a, 7c8730f)
• Fixed resource leak issues (commits: 16e517c, 29279e8)
• Added configurable tolerance value via ParamKeyEnum.TOLERANT (commit: a4f8a99)

Documentation

• Online Demo: http://captcha.tianai.cloud
• Online Documentation: http://doc.captcha.tianai.cloud
• License: MulanPSL-2.0