BUILD FAILED in 3s Could not install the app on the device, read the error above for details. Make s

错误提示： 

Scanning folders for symlinks in D:\ReactNativeWorkSpace\react_native_complete_demo\node_modules (32ms)
JS server already running.
Building and installing the app on the device (cd android && gradlew.bat installDebug)...

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'AwesomeProject'.
> Could not resolve all files for configuration ':classpath'.
   > Could not resolve com.android.tools.build:gradle:3.1.4.
     Required by:
         project :
      > Could not resolve com.android.tools.build:gradle:3.1.4.
         > Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.1.4/gradle-3.1.4.pom'.
            > Could not HEAD 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.1.4/gradle-3.1.4.pom'.
               > Connect to 127.0.0.1:1087 [/127.0.0.1] failed: Connection refused: connect
      > Could not resolve com.android.tools.build:gradle:3.1.4.
         > Could not get resource 'https://jcenter.bintray.com/com/android/tools/build/gradle/3.1.4/gradle-3.1.4.pom'.
            > Could not HEAD 'https://jcenter.bintray.com/com/android/tools/build/gradle/3.1.4/gradle-3.1.4.pom'.
               > Connect to 127.0.0.1:1087 [/127.0.0.1] failed: Connection refused: connect

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

* Get more help at https://help.gradle.org

BUILD FAILED in 3s
Could not install the app on the device, read the error above for details.
Make sure you have an Android emulator running or a device connected and have
set up your Android development environment:
https://facebook.github.io/react-native/docs/android-setup.html