Android Studio cannot resolve dependency - android-studio

Question

I use Android studio to create a blank project, but cannot compile.
below is its error:
Error:A problem occurred configuring project ':app'.
> Could not resolve all dependencies for configuration':app:_debugUnitTestApkCopy'.
> Could not resolve junit:junit:4.12.
Required by:
project :app
> Could not resolve junit:junit:4.12.
> Could not get resource 'https://jcenter.bintray.com/junit/junit/4.12/junit-4.12.pom'.
> Could not GET 'https://jcenter.bintray.com/junit/junit/4.12/junit-4.12.pom'.
> jcenter.bintray.com:443 failed to respond
I tried to use a proxy
and checked proxy settings with the failed url 'https://jcenter.bintray.com/junit/junit/4.12/junit-4.12.pom'
and it show me success
but when I compile the project, it's still the same error.
this is my gradle.properties file:
systemProp.http.proxyHost=127.0.0.1
systemProp.http.proxyPort=1080
systemProp.https.proxyHost=127.0.0.1
systemProp.https.proxyPort=1080
this is project build.gradle file:
// 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:2.3.3'
// 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
}
this is app build.gradle file:
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
buildToolsVersion "25.0.2"
defaultConfig {
applicationId "com.example.myapplication"
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(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-v7:26.+'
compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha7'
testCompile 'junit:junit:4.12'
}

Answer 1

finally, I solved my question
the proxy I use is a sockts5 proxy
the autogenerate gradle.properties file use a http proxy
after I change the gradle.properties it's worked
this is my new gradle.properties:
org.gradle.jvmargs=-Xmx1536m -DsocksProxyHost=127.0.0.1 -DsocksProxyPort=1080