react-native run-android => Could not resolve all

Question

I insert java_home in environment correctly and test it in cmd. I am connecting to the internet with the proxy and can download react-native packages. adb devices run correctly on cmd, but when running "react-native run-android" command I give below error:

D:\amoz\react-native\1\pro\test>react-native run-android
Scanning folders for symlinks in D:\amoz\react- 
native\1\pro\test\node_modules (8
7ms)
Starting JS server...
Building and installing the app on the device (cd android && gradlew.bat 
install
Debug)...
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by 
org.gradle.internal.reflect.JavaMethod (fi
le:/C:/Users/01/.gradle/wrapper/dists/gradle-3.5.1- 
all/42vjebfdws9pjts3l4bouoq0p
/gradle-3.5.1/lib/gradle-base-services-3.5.1.jar) to method 
java.lang.ClassLoade
r.getPackages()
WARNING: Please consider reporting this to the maintainers of 
org.gradle.interna
l.reflect.JavaMethod
WARNING: Use --illegal-access=warn to enable warnings of further illegal 
reflect
ive access operations
WARNING: All illegal access operations will be denied in a future 
release

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'test'.
> Could not resolve all dependencies for configuration ':classpath'.
 > Could not resolve com.android.tools.build:gradle:2.3.3.
 Required by:
     project :
  > Could not resolve com.android.tools.build:gradle:2.3.3.
     > Could not get resource 'https://jcenter.bintray.com/com/android/tools
/build/gradle/2.3.3/gradle-2.3.3.pom'.
        > Could not GET 'https://jcenter.bintray.com/com/android/tools/build
/gradle/2.3.3/gradle-2.3.3.pom'.
           > Connect to jcenter.bintray.com:443 [jcenter.bintray.com/108.168
.243.150] failed: Connection timed out: connect

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

BUILD FAILED

Total time: 26.739 secs
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/getting-started.html

Even I add Google() to build.gradle in allprojects{} It doesn't work again. and still giving that error. By the way, I am using JDK version 9 and gradle version 2.3.3

Answer 1

Unfortunately, Jcenter blocks requests from Iran due to US sanctions. You can use Hotspot Shield to connect to Jcenter, other VPN's providers may not work correctly. and i suggest you to update your gradle by this changes:

1- change gradle version to classpath 'com.android.tools.build:gradle:3.1.1' in android/build.gradle

2- change distributionUrl from android/gradle/wrapper/gradle-wrapper.properties to distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip

3- add repository to android/build.gradle like this:

repositories {
        mavenLocal()
        google()
        jcenter()
        maven { url "https://jitpack.io" }
        maven { url 'https://maven.google.com' }
    }

4- start Hotspot Shield and build project.

I hope this may help you.