解决Gradle自有项目依赖问题：实现独立构建与依赖自动生成

Project Structure & Dependency Chain #

Here’s a clear breakdown of each project and its dependencies (excluding open-source libraries):

• ProjectCommonUtil: No dependencies
• ProjectBatchUtil: No dependencies
• ProjectHttpClientUtil: Depends on ProjectCommonUtil (labeled a in your description)
• ProjectWeb: Depends on ProjectCommonUtil (a), c, d
• ProjectBatchWithMainClass: Depends on b, c, d — where d itself depends on ProjectCommonUtil (a)

Core Requirements & Problems to Solve #

1. Support independent build of each individual project
2. Resolve dependencies based on JAR files in the target project’s lib directory
3. Automatically build missing dependent projects and copy their JARs to the target’s lib directory when a dependency is missing

Proposed Implementation Approach #

To meet these needs, set up a build script (e.g., Gradle, Maven, or custom shell script) with the following logic:

1. Define a Clear Dependency Mapping #

First, create a mapping that links each dependency label to its corresponding project, including transitive relationships:

dependencyMap = [
    "ProjectWeb": ["a", "c", "d"],
    "ProjectHttpClientUtil": ["a"],
    "ProjectBatchWithMainClass": ["b", "c", "d"],
    "d": ["a"],
    "a": "ProjectCommonUtil",
    "b": "<your-project-b-name>",
    "c": "<your-project-c-name>",
    "d": "<your-project-d-name>"
]

(Replace placeholders like <your-project-b-name> with actual project titles)

2. Add Dependency Check & Auto-Build Logic #

For any project being built:

• Scan its lib directory to verify all required JARs exist
• If a JAR is missing:
  • Use the mapping to find which project corresponds to that dependency
  • Trigger a build for the dependent project first
  • Copy the resulting JAR from the dependent project’s build output (e.g., build/libs/) to the target project’s lib directory
  • Repeat this process recursively for transitive dependencies (like building a first when d is missing, since d depends on a)

3. Enable Standalone Project Builds #

Ensure each project can be built independently:

• In Gradle/Maven, structure projects as subprojects with individual build configs, allowing commands like ./gradlew :ProjectWeb:build to build only ProjectWeb
• In a custom shell script, add a parameter to specify the target project (e.g., ./build.sh ProjectBatchUtil)

Example Workflow #

Let’s walk through building ProjectBatchWithMainClass when its lib directory lacks d’s JAR:

1. The build script checks ProjectBatchWithMainClass/lib and finds d.jar is missing
2. It looks up that d depends on a (ProjectCommonUtil)
3. Checks if a.jar exists in d’s lib — if not, triggers a build of ProjectCommonUtil
4. Copies ProjectCommonUtil.jar to d’s lib, then builds d
5. Copies d.jar to ProjectBatchWithMainClass/lib
6. Proceeds to build ProjectBatchWithMainClass once all dependencies are present

内容的提问来源于stack exchange，提问作者BillS