React Native安卓构建报错：无法调用null对象的mavenDeployer()方法（第131行）

问题描述 #

构建React Native安卓项目时触发错误：

Cannot invoke method mavenDeployer() on null object (line 131)

相关代码片段：

仓库配置 #

repositories {
    mavenLocal()
    maven {
        // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
        url "$rootDir/../node_modules/react-native/android"
    }
    maven {
        // Android JSC is installed from npm
        url "$rootDir/../node_modules/jsc-android/dist"
    }
    google()
    jcenter()
}

任务配置（错误行131） #

task installArchives(type: Upload) {
    configuration = configurations.archives
    repositories.mavenDeployer { // line 131
        // Deploy to react-native-event-bridge/maven, ready to publish to npm
        repository url: "file://${projectDir}/../android/maven"
        configureReactNativePom pom
    }
}

尝试修改repositories.mavenDeployer相关代码后，错误依旧。

修复方案 #

方案1：适配新版Gradle（推荐） #

Upload任务和mavenDeployer在Android Gradle Plugin 4.0+中已被废弃，改用maven-publish插件：

1. 在模块build.gradle顶部引入插件：

plugins {
    id 'com.android.library' // 若为应用模块则用id 'com.android.application'
    id 'maven-publish'
}

2. 替换原installArchives任务为发布配置：

afterEvaluate {
    publishing {
        publications {
            maven(MavenPublication) {
                from components.release // 按需切换为debug
                groupId = "你的组ID" // 示例：com.yourteam
                artifactId = "react-native-event-bridge"
                version = "1.0.0"

                pom {
                    name = "React Native Event Bridge"
                    description = "自定义事件桥接库"
                    // 若需复用原configureReactNativePom逻辑，可在此处迁移相关配置
                }
            }
        }
        repositories {
            maven {
                url = uri("file://${projectDir}/../android/maven")
            }
        }
    }
}

3. 执行发布命令：

./gradlew publishToMavenLocal

方案2：修复旧版Gradle任务写法 #

若仍使用旧版Gradle，需确保任务内repositories正确初始化，原写法中repositories对象未实例化导致null：

修改任务代码：

task installArchives(type: Upload) {
    configuration = configurations.archives
    repositories {
        mavenDeployer {
            repository url: "file://${projectDir}/../android/maven"
            configureReactNativePom pom
        }
    }
}

方案3：检查自定义方法有效性 #

确认configureReactNativePom方法在build.gradle中已正确定义，若该方法缺失或异常，也会间接导致mavenDeployer初始化失败。

内容的提问来源于stack exchange，提问作者honk19