从导入的依赖项覆盖 Gradle 项目配置

Question

I'm developing a project which serves as a platform for many other projects. It is distributed as a library.

I'm facing the following issue: I don't have control over the other projects and I want to have a consistent logging format. In order to do that I want to have specific logging dependencies versions which are declared in my project's build.gradle so I can manipulate them.

How should I write my Gradle configuration so it can override or force a specific dependency version? I'm using Gradle 6.2.1 and I've tried

api(group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.13.0') {
        force = true
    }

but it doesn't work.

Answer 1

There is no way for a library to dictate/override the dependencies of a consuming project.

If you want to control other projects and ensure they are using the appropriate libraries/versions, then you will need to write a Gradle plugin that overrides the dependency resolution of the project.

For your use case (if I am understanding it correct) the plugin could be as simple as:

public class LoggingResolutionPlugin implements Plugin<Project> {

  @Override
  public void apply(Project project) {

    project.getConfigurations().all((configuration) -> {
      configuration.resolutionStrategy((resolutionStrategy) -> {
        resolutionStrategy.eachDependency((dependency) -> {

          ModuleVersionSelector requested = dependency.getRequested();
          if(requested.getGroup().equals("org.apache.logging.log4j")
          && requested.getName().equals("log4j-core")) {
             dependency.useVersion("2.13.0");
             dependency.because("Library must use 2.13.0 because reasons.");
          }
        });
      });
    });
  }
}

Further reading:

• https://docs.gradle.org/current/userguide/resolution_rules.html
• https://docs.gradle.org/current/userguide/custom_plugins.html
• https://blog.gradle.org/guava
• https://blog.gradle.org/alignment-with-gradle-module-metadata