重建Android项目触发NullPointerException，编译失败求排查方案

错误日志 #

java.lang.NullPointerException: Cannot invoke "String.length()" because "<parameter1>" is null

Execution failed for task ':app:dexBuilderDebug'.
 Could not resolve all files for configuration ':app:detachedConfiguration18'.
    Failed to transform jetified-appcompat-resources-1.7.0-beta01-runtime.jar to match attributes {artifactType=ext-dex-dexBuilderDebug, org.gradle.libraryelements=jar, org.gradle.usage=java-runtime}.
       Execution failed for DexingExternalLibArtifactTransform: C:\Users\John Doe\.gradle\caches\transforms-3\a17cb0bdbb9802eb5b30084992aad901\transformed\jetified-appcompat-resources-1.7.0-beta01-runtime.jar.
          Error while dexing.
    Failed to transform appcompat-1.7.0-beta01-runtime.jar to match attributes {artifactType=ext-dex-dexBuilderDebug, org.gradle.libraryelements=jar, org.gradle.usage=java-runtime}.
       Execution failed for DexingExternalLibArtifactTransform: C:\Users\John Doe\.gradle\caches\transforms-3\cb6538e8f72401bf3ec35fdf09737324\transformed\appcompat-1.7.0-beta01-runtime.jar.
          Error while dexing.

排查解决方案 #

• 清理Gradle缓存：删除本地Gradle缓存目录C:\Users\John Doe\.gradle\caches，然后执行./gradlew clean build重新编译，排除缓存损坏导致的依赖转换异常。
• 降级AppCompat依赖版本：当前使用的appcompat-1.7.0-beta01为测试版本，存在稳定性隐患。将依赖替换为稳定版，比如implementation 'androidx.appcompat:appcompat:1.6.1'，同步项目后重试编译。
• 校验Java版本兼容性：确保项目Java版本与Gradle插件版本匹配（Gradle 7.x+建议使用Java 11），在gradle.properties中配置：

  org.gradle.java.home=/path/to/your/java11
  

• 尝试禁用Jetifier：若项目无需兼容旧版支持库，在gradle.properties中添加配置关闭Jetifier，排查是否是依赖转换环节出问题：

  android.enableJetifier=false
  

• 检查依赖冲突：执行./gradlew app:dependencies导出依赖树，确认是否存在多版本AppCompat或相关库冲突，统一依赖版本后重新编译。

内容的提问来源于stack exchange，提问作者Lechucico