是否可以将自定义Java库导入Gradle buildSrc Java类？

Question

我用Java编写了一个定制的Gradle任务，它生成一个Java文件。我的任务位于我的项目的buildSrc目录中。 我想扩展这个任务，但我需要从另一个项目访问我的自定义Java库

import org.gradle.api.DefaultTask;
import org.gradle.api.tasks.TaskAction;

import my.custom.java.library.*;

public class AutoGenerateTask extends DefaultTask {

  @TaskAction
  public void generate() {
    ...
    // java code
    ...
  }

}

我是格拉德尔的新手，我不知道这是否可能

Answer 1

是的，有可能。可以使用Gradle复合构建将其他依赖项包含到构建逻辑中

假设

让我们先做一些假设：

简化结构

.
├── project-custom-lib
│   ├── build.gradle.kts
│   ├── settings.gradle.kts
│   └── src/main
│      └── java/xx/oo/Demo.java
└── project-app
    ├── buildSrc
    │   ├── build.gradle.kts
    │   └── src/main
    │      ├── java/com/example/AutoGenerateTask.java
    │      └── kotlin/com.example.java-conventions.gradle.kts
    ├── aaa
    │   ├── build.gradle.kts
    │   └── src/
    ├── bbb
    │   ├── build.gradle.kts
    │   └── src/
    └── settings.gradle.kts

project-custom-lib/build.gradle.kts

...

group = "xx.oo"

project-custom-lib/settings.gradle.kts

rootProject.name = "project-custom-lib"

project-custom-lib/src/main/java/xx/oo/Demo.java

package xx.oo;

public class Demo {
    public static final String VALUE = "DEMO!";
}

project-app/settings.gradle.kts

rootProject.name = "project-app"
include("aaa", "bbb")

project-app/buildSrc/src/kotlin/com.example.java-conventions.gradle.kts

import com.example.AutoGenerateTask;

...

tasks.register<AutoGenerateTask>("autogen")

解决方案

第一步：使buildSrc显式

buildSrc是一个特殊的文件夹，隐式地作为includeBuild处理。但是，它目前不支持包含其他版本（Gradle 7.0）。因此，我们必须首先明确地打破这一规则

这一步很简单。只需将文件夹重命名为buildSrc以外的名称，例如build-conventions，并为其创建一个空的settings.gradle.kts：

$ mv project-app/buildSrc project-app/build-conventions
$ touch project-app/build-conventions/settings.gralde.kts

然后将build-conventions包含在project-app/settings.gradle.kts中：

rootProject.name = "project-app"
includeBuild("build-conventions")
include("aaa", "bbb")

这些更改不应破坏您的项目构建。您现在可以构建它：

$ cd project-app
$ ./gradlew build

BUILD SUCCESSFUL in XXs
XX actionable tasks: XX executed, XX up-to-date

# If you write some tests inside build-conventions, you definitely need this.
$ ./gradlew -p build-conventions build

BUILD SUCCESSFUL in XXs
XX actionable tasks: XX executed, XX up-to-date

第2步：使project-custom-lib的类在build-conventions

中可解析

实际上，Gradle在Composite Builds中描述了如何做到这一点：

By default, Gradle will configure each included build in order to determine the dependencies it can provide. The algorithm for doing this is very simple: Gradle will inspect the group and name for the projects in the included build, and substitute project dependencies for any external dependency matching ${project.group}:${project.name}.

我们先把这一行添加到project-app/build-conventions/settings.gradle.kts中：

includeBuild("../../project-custom-lib")

然后在project-app/build-conventions/build.gradle.kts中添加依赖项：

...

dependencies {
    implementation("xx.oo:project-custom-lib")
}

现在，您应该能够在代码中导入它：

...

import xx.oo.Demo;

public class AutoGenerateTask extends DefaultTask {
    @TaskAction
    public void generate() {
        System.out.println(Demo.VALUE);

        ...
    }
}