Dependency conflict in android studio when using firebase

Question

I built a normal android app which uses Firebase to store data(name,email and number) and it runs perfectly but i have a dependency conflict error which i am unable to solve. the message which i get "Message Gradle Build" is: Error:Execution failed for task ':app:preDebugAndroidTestBuild'.

Conflict with dependency 'com.android.support:support-annotations' in project ':app'. Resolved versions for app (25.2.0) and test app (25.4.0) differ. See https://d.android.com/r/tools/test-apk-dependency-conflicts.html for details.

and my build.gradle file contains:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.arya.anish.myfirebaseexample"
        minSdkVersion 19
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.google.firebase:firebase-database:11.0.4'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
}


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

how to overcome this error?

Answer 1

try adding this to your app level .gradle file

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.google.firebase:firebase-database:11.0.4'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation('com.android.support.test.espresso:espresso-core:3.0.1') {
    exclude group: 'com.android.support', module: 'support-annotations'
    }
}

Answer 2

finally figured out how to solve the dependency conflict i added this line in the build.gradle file in the depndencies block:

compile 'com.android.support:support-annotations:27.0.2'

and bingo, no errors now.