使用Hilt依赖注入时触发kapt编译错误的问题排查

问题背景 #

我是依赖注入（Dependency Injection）新手，正在学习使用Hilt。按照Android官方文档配置了Hilt 2.44依赖，已在Manifest中配置了自定义Application，但运行应用时触发kapt编译错误。

配置与代码 #

项目级build.gradle.kts #

// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
    alias(libs.plugins.android.application) apply false
    alias(libs.plugins.jetbrains.kotlin.android) apply false
    id("com.google.dagger.hilt.android") version "2.44" apply false
}

应用级build.gradle.kts #

plugins {
    alias(libs.plugins.android.application)
    alias(libs.plugins.jetbrains.kotlin.android)
    id("kotlin-kapt")
    id("com.google.dagger.hilt.android")
}

android {
    namespace = "com.jihan.dependencyinjection"
    compileSdk = 34

    defaultConfig {
        applicationId = "com.jihan.dependencyinjection"
        minSdk = 26
        targetSdk = 34
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }
}

dependencies {

    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.appcompat)
    implementation(libs.material)
    implementation(libs.androidx.activity)
    implementation(libs.androidx.constraintlayout)
    testImplementation(libs.junit)
    androidTestImplementation(libs.androidx.junit)
    androidTestImplementation(libs.androidx.espresso.core)

    implementation("com.google.dagger:hilt-android:2.44")
    kapt("com.google.dagger:hilt-android-compiler:2.44")
}

应用代码 #

UserApplication类

package com.jihan.dependencyinjection

import android.app.Application
import dagger.hilt.android.HiltAndroidApp
import javax.inject.Inject

@HiltAndroidApp
class UserApplication : Application() {

    @Inject
    lateinit var userRepository: UserRepository

    override fun onCreate() {
        super.onCreate()
        userRepository.saveUser("jihankhyasjdf","dfhaskjdhfkjsadh")

    }
}

UserRepository类

package com.jihan.dependencyinjection

import android.util.Log
import javax.inject.Inject

class UserRepository @Inject constructor() {

    fun saveUser(email:String,pass:String){
        Log.d("jihankhan","user saved in database")
    }

}

错误信息 #

Execution failed for task ':app:kaptDebugKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.gradle.internal.KaptWithoutKotlincTask$KaptExecutionWorkAction

* Try:
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:kaptDebugKotlin'.
    ...
Caused by: java.lang.IllegalStateException: Unsupported metadata version. Check that your Kotlin version is >= 1.0
    ...

Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

For more on this, please refer to https://docs.gradle.org/8.7/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.

BUILD FAILED in 4s
28 actionable tasks: 2 executed, 26 up-to-date

解决方案 #

这个错误的核心原因是Hilt版本与当前使用的Kotlin版本不兼容。Hilt 2.44对Kotlin版本有特定要求，若你使用的是较新的Kotlin版本（如1.8+），就会触发元数据版本不支持的错误。

解决步骤：

1. 升级Hilt到兼容版本：将Hilt版本升级到与你的Kotlin版本匹配的版本。例如，若Kotlin版本是1.8.x，可升级到Hilt 2.48及以上；若为1.9.x，建议使用Hilt 2.50+。
   • 修改项目级build.gradle.kts中的Hilt插件版本：

     id("com.google.dagger.hilt.android") version "2.50" apply false
     

   • 修改应用级build.gradle.kts中的依赖版本：

     implementation("com.google.dagger:hilt-android:2.50")
     kapt("com.google.dagger:hilt-android-compiler:2.50")
     

2. 同步Gradle并清理重建项目：执行File -> Sync Project with Gradle Files，然后依次执行Build -> Clean Project和Build -> Rebuild Project。

若不确定当前Kotlin版本，可在项目级build.gradle.kts中查看libs.plugins.jetbrains.kotlin.android对应的版本，或在Android Studio的File -> Project Structure -> Modules -> app -> Kotlin Version中查看。

内容的提问来源于stack exchange，提问作者Jihan Khan