can't build android project it shows error

问题

project gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-alpha3'
        classpath 'com.google.gms:google-services:3.0.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

App Gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.example.arun4fms.efix"
        minSdkVersion 17
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        packagingOptions {
            exclude 'META-INF/LICENSE'
            exclude 'META-INF/LICENSE-FIREBASE.txt'
            exclude 'META-INF/NOTICE'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.google.firebase:firebase-database:10.2.0'
    compile 'com.google.firebase:firebase-crash:10.2.0'
    compile 'com.google.firebase:firebase-auth:10.2.0'
    compile 'com.chabbal:slidingdotsplash:1.0.2'
    compile 'com.google.firebase:firebase-core:10.2.0'
    compile 'com.firebase:firebase-client-android:2.5.2'
    compile 'com.android.support:appcompat-v7:25.2.0'
    compile 'com.android.support:design:25.2.0'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
}
apply plugin: 'com.google.gms.google-services'

Error:A problem occurred configuring root project 'webapp'.

Could not resolve all dependencies for configuration ':classpath'. Could not find com.android.tools.build:gradle:3.0.0-alpha3. Searched in the following locations: file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/tools/build/gradle/3.0.0-alpha3/gradle-3.0.0-alpha3.pom file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/tools/build/gradle/3.0.0-alpha3/gradle-3.0.0-alpha3.jar https://jcenter.bintray.com/com/android/tools/build/gradle/3.0.0-alpha3/gradle-3.0.0-alpha3.pom https://jcenter.bintray.com/com/android/tools/build/gradle/3.0.0-alpha3/gradle-3.0.0-alpha3.jar Required by: project :

回答1:

As already answered here:

Google have new maven repo, so it could be the reason.

https://android-developers.googleblog.com/2017/05/android-studio-3-0-canary1.html

section Google's Maven Repository

https://developer.android.com/studio/preview/features/new-android-plugin-migration.html https://developer.android.com/studio/build/dependencies.html#google-maven

Add Google’s Maven Repository to the buildscript repositories section to fix it like @KG87 did here.

buildscript {
    repositories {
        jcenter()
        maven { url "https://maven.google.com" } // Add this line to fix it
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-alpha3'
        ...
    }
}

As explained here:

The repositories in the buildScript block are used to fetch the dependencies of your buildScript dependencies. These are the dependencies that are put on the classpath of your build and that you can refer to from your build file. For instance, extra plugins that exist on the internet.

The repositories on the root level are used to fetch the dependencies that your project depends on. So all the dependencies you need to compile your project.

And here:

The buildScript block determines which plugins, task classes, and other classes are available for use in the rest of the build script. Without a buildScript block, you can use everything that ships with Gradle out-of-the-box. If you additionally want to use third-party plugins, task classes, or other classes (in the build script!), you have to specify the corresponding dependencies in the buildScript block.

As announced here:

The Android Gradle Plugin 3.0.0-alpha3 was also released through maven.google.com.

So, try to fix it by adding Google’s Maven Repository.

buildscript {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-alpha3'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

Also add the repository here for other dependencies like the support libraries like this:

Make sure that the repositories section includes a maven section with the "https://maven.google.com" endpoint. For example:

allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

The difference is explained here

The "buildscript" block only controls dependencies for the buildscript process itself, not for the application code, which the top-level "dependencies" block controls.

For instance, you could define dependencies in "buildscript/classpath" that represent Gradle plugins used in the build process. Those plugins would not be referenced as dependencies for the application code.

As commented here by @lugegege, this version doesn't exist in Bintray JCenter:

com.android.tools.build.gradle latest version is 2.5.0-alpha-preview-02, there is no 3.0.0-alpha3

回答2:

com.android.tools.build.gradle latest version is 2.5.0-alpha-preview-02, there is no 3.0.0-alpha3

回答3:

Use this.. This may work because this worked in my case:

dependencies {
classpath 'com.android.tools.build:gradle:2.0.0-alpha3'
classpath 'com.google.gms:google-services:2.0.0-alpha3'
}

and put this at the end of the app-level build.gradle file (after the dependencies).

 apply plugin: 'com.google.gms.google-services'

I have no clue why putting this at the end (and not at the beginning ) solves the error.

Ok… So trying to put an end to all problems you guys have faced with my solution

This is my final app level gradle

apply plugin: 'com.android.application'

android {
compileSdkVersion 23
buildToolsVersion "23.0.2"

defaultConfig {
    applicationId "your-app-name"
    minSdkVersion 16
    targetSdkVersion 23
    versionCode 1
    versionName "1.0"
    }
    buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 
        'proguard-rules.pro'
    }
    }
     }

   repositories {
    jcenter()
    }

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.1.1'
compile 'com.google.android.gms:play-services:8.4.0'
compile 'com.android.support:design:23.1.1'
compile 'com.mcxiaoke.volley:library:1.0.6@aar'
}

 apply plugin: 'com.google.gms.google-services'

and this is my final project level gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

   buildscript {
   repositories {
    jcenter()
     }
    dependencies {
    classpath 'com.android.tools.build:gradle:2.0.0-alpha3'
    classpath 'com.google.gms:google-services:2.0.0-alpha3'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
    }
    }

   allprojects {
   repositories {
    jcenter()
   }
   }

Compare this with your own gradle files, and add or modify any values which are different from what I've written.

回答4:

I had the same problem this morning ! As Vishal said, there is no gradle-3.0.0-alpha3.. I am sure that, since I downloaded "Android studio 3.0 Canary (Alpha3)", I was on on the same version of gradle (3.0.0 alpha3), and it worked ! (Since today).

So I've put : classpath 'com.android.tools.build:gradle:2.3.2' to compile.

EDIT : I have two versions of Android studio, When I used Android Studio 3.0, it changes gradle to gradle 3.0.0-alpha3 !

回答5:

write these gradles..

compile 'com.android.support:appcompat-v7:25.0.2'
compile 'com.android.support:design:25.0.2'
classpath 'com.android.tools.build:gradle:2.2.3'

来源：https://stackoverflow.com/questions/44366261/cant-build-android-project-it-shows-error