Error:(23, 17) Failed to resolve: junit:junit:4.12?
把testCompile 'junit:junit:4.12'注释或删除掉，在stackoverflow中有明确的原由和解决方法，只需在Application的build.gradle文件中添加
maven { url 'http://repo1.maven.org/maven2' }
具体如下所示：
android {
[...]
repositories {
maven { url 'http://repo1.maven.org/maven2' }
}
[...]
}
工程的build.gradle完整如下：
apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion "25.0.1"
defaultConfig {
applicationId "com.diudiu.myapplicationtest"
minSdkVersion 17
targetSdkVersion 25
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
repositories {
maven { url 'http://repo1.maven.org/maven2' }
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.+'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
}
