无法解决：com.android.support.test.espresso

Question

My build.gradle file is below:

apply plugin: 'com.android.application'

android {

compileSdkVersion 26

buildToolsVersion '25.0.3'

defaultConfig {

    applicationId "com.xavier.hello"

    minSdkVersion 15

    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 {

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.android.support.constraint:constraint-layout:1.0.2'

testCompile 'junit:junit:4.12'

}

It gives following error every time:

Answer 1

I had the same problem when I wanted to try Espresso.

I've resolved it by adding

maven {
        url "https://maven.google.com"
    }

to

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

Answer 2

This can be caused by two different issues:

1. A problem with your gradle file(s).
2. Internet connectivity issues.

The problem in my case was Internet connectivity. I actually was connected to the Internet when trying to build my project, but I had a very slow connection. Once I had solid wifi, I ran the build again and this issue went away. You also may need to adjust your settings for running online/offline, as Android Studio will tell you. In your project's build.gradle file you should have this maven reference in your repositories:

repositories {
    jcenter()
    maven {
        url 'https://maven.google.com/'
        name 'Google'
    }
    google() //you may or may not need this line
}