Java注解处理器编译时未执行问题排查求助

问题背景 #

我正在实现一个基于注解处理的类库，可在编译时自动生成Fixture类。项目采用单仓库结构：

|-- fixturize
    |
    |--fixturize-core
    |--fixturize-playground

fixturize-core中同时定义了@Fixture注解及对应的注解处理器FixtureProcessor，使用AutoService生成META-INF/services/javax.annotation.processing.Processor文件，该文件已确认存在于编译后的类文件中。

fixturize-core的build.gradle配置 #

plugins {
    id "java"
    id "io.freefair.lombok" version "8.6"
}

ext {
    nashornVersion = "15.4"
    guavaVersion = "33.2.1-jre"
    autoServiceVersion = "1.1.1"

    junitVersion = "5.10.0"
    assertJVersion = "3.25.1"
    mockitoVersion = "5.12.0"
    compileTestingVersion = "0.21.0"
    lombokVersion = "1.18.34"
}

dependencies {
    implementation "com.google.auto.service:auto-service:$autoServiceVersion"
    annotationProcessor "com.google.auto.service:auto-service:$autoServiceVersion"

    implementation "com.google.guava:guava:$guavaVersion"
    implementation "org.openjdk.nashorn:nashorn-core:$nashornVersion"

    testImplementation platform("org.junit:junit-bom:$junitVersion")
    testImplementation "org.junit.jupiter:junit-jupiter"
    testImplementation "org.assertj:assertj-core:$assertJVersion"
    testImplementation "org.mockito:mockito-junit-jupiter:$mockitoVersion"
    testImplementation "com.google.testing.compile:compile-testing:$compileTestingVersion"
    testImplementation "org.projectlombok:lombok:$lombokVersion"
}

test {
    useJUnitPlatform()
}

fixturize-playground的build.gradle配置 #

plugins {
    id "java"
    id "io.freefair.lombok" version "8.6"
}

tasks.withType(JavaCompile) {
    doFirst {
        println "AnnotationProcessorPath for $name is ${options.getAnnotationProcessorPath().getFiles()}"
    }
}

compileJava {
    options.annotationProcessorPath = configurations.annotationProcessor
}

dependencies {
    implementation project(":fixturize-core")
    annotationProcessor project(":fixturize-core")

    testImplementation platform('org.junit:junit-bom:5.10.0')
    testImplementation 'org.junit.jupiter:junit-jupiter'
}

test {
    useJUnitPlatform()
}

测试用标注类 #

import de.floydkretschmar.fixturize.annotations.Fixture;

@Fixture
public class Test {
    private int field;
}

执行./gradlew clean build时，未生成目标Fixture类，编译日志显示自定义注解处理器不在注解处理器路径中。

排查与解决方案 #

1. 确保AutoService配置文件被正确打包 #

检查fixturize-core/build/libs/fixturize-core-*.jar，确认META-INF/services/javax.annotation.processing.Processor文件存在，且内容为处理器的全类名（如de.floydkretschmar.fixturize.processors.FixtureProcessor）。

若文件缺失，在fixturize-core的build.gradle中添加打包配置：

jar {
    from sourceSets.main.output.resourcesDir
    from sourceSets.main.output.classesDirs
}

2. 移除手动设置的注解处理器路径 #

Gradle默认会自动管理annotationProcessor配置的依赖路径，手动设置可能覆盖默认逻辑。删除fixturize-playground中以下配置：

compileJava {
    options.annotationProcessorPath = configurations.annotationProcessor
}

3. 直接引用fixturize-core的打包jar作为注解处理器 #

修改fixturize-playground的依赖配置，确保使用包含完整资源的jar文件：

dependencies {
    implementation project(":fixturize-core")
    annotationProcessor files(project(":fixturize-core").jar.archiveFile)
}

4. 验证处理器类的可见性与注解配置 #

• 确保FixtureProcessor类为public修饰
• 检查@SupportedAnnotationTypes中的注解全类名与@Fixture注解的实际全类名完全一致（包括包名）

5. 清理缓存后重新构建 #

执行以下命令彻底清除缓存并重新构建：

./gradlew clean build --no-build-cache

内容的提问来源于stack exchange，提问作者floydk