新建Android项目构建失败：无法解析JUnit等依赖求助

Hey there! I remember hitting almost identical dependency snags when I built my first Android app—totally frustrating, but easy to fix once you spot the configuration kinks. Let's get your project up and running smoothly.

What's Causing the Problem? #

Your errors boil down to two key issues:

• Incomplete repository configuration: Gradle can't locate JUnit and JSR305 because it's not looking in the right online repositories.
• Duplicate android blocks: Your app-level Gradle file has two separate android{} sections, which can confuse the build system and prevent settings from applying correctly.

Step 1: Fix the Project-Level build.gradle #

Update your top-level build file to ensure Gradle can access all necessary libraries. Replace your allprojects block with this:

allprojects {
    repositories {
        google() // Official repo for AndroidX components
        jcenter() // Hosts JUnit and other third-party libraries
        mavenCentral() // Fallback repo for libraries migrating from jcenter
    }
}

google() is the primary source for AndroidX dependencies, while jcenter() and mavenCentral() host the JUnit and JSR305 files your project needs.

Step 2: Clean Up the App-Level build.gradle #

Merge the two separate android{} blocks in your app's Gradle file—this eliminates configuration conflicts. Here's the corrected version:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.0"
    defaultConfig {
        applicationId "com.example.myapplication"
        minSdkVersion 28
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    // Move resolution strategy into the single android block
    configurations.all {
        resolutionStrategy.force 'com.google.code.findbugs:jsr305:1.3.9'
    }
}

dependencies {
    implementation 'androidx.appcompat:appcompat:1.0.2'
    testImplementation 'junit:junit:4.12'
}

Step 3: Final Troubleshooting Steps #

1. Click File > Sync Project with Gradle Files in Android Studio to apply your changes.
2. If sync fails, go to File > Invalidate Caches... > Invalidate and Restart—this clears any cached bad configuration that might be sticking around.
3. Double-check your internet connection: Gradle needs to download these dependencies, so make sure you're not blocked by a firewall or proxy.

Why This Works #

• Consolidating the android blocks ensures Gradle reads all your configuration correctly without conflicts.
• Adding the proper repositories tells Gradle exactly where to look for the missing JUnit and JSR305 libraries.
• The resolutionStrategy.force line ensures Gradle uses a JSR305 version that's fully compatible with your AndroidX setup.

You've got this—your first Android app is almost ready to run!

内容的提问来源于stack exchange，提问作者Aman