今天，我开始学习Flutter，并成功下载了所有内容。但是，当我运行我的应用时，调试器（VSCode和Android Studio）都给我
这个错误。

Launching lib\main.dart on sdk gphone x86 in debug mode...

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'android'.
> Could not resolve all artifacts for configuration ':classpath'.
   > Could not download builder.jar (com.android.tools.build:builder:3.5.0)
      > Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/builder/3.5.0/builder-3.5.0.jar'.
         > Premature end of Content-Length delimited message body (expected: 8174407; received: 4456416
   > Could not download bundletool.jar (com.android.tools.build:bundletool:0.9.0)
      > Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/bundletool/0.9.0/bundletool-0.9.0.jar'.
         > Premature end of Content-Length delimited message body (expected: 5248142; received: 4456416

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org

BUILD FAILED in 21m 37s
Gradle task assembleDebug failed with exit code 1
Exited (sigterm)

And this is build.gradle

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

由于我要解决6个小时的问题，因此不胜感激！

注意：-这是我在Flutter和Android Studio中首次使用VSCode的应用程序