无法运行 flutter 博士 - - 执照

Question

C:\Users\USER>flutter doctor
Doctor summary (to see all details, run flutter doctor -v):

[√] Flutter (Channel stable, 2.0.6, on Microsoft Windows [Version 10.0.19042.928], locale en-US)

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    X Android license status unknown.

      Run flutter doctor --android-licenses to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/windows#android-setup for more details.

[√] Chrome - develop for the web

[√] Android Studio

[√] VS Code (version 1.56.1)

[√] Connected device (2 available)

! Doctor found issues in 1 category.

C:\Users\USER>flutter doctor --android-licenses

Error: Could not find or load main class J\AppData\Local\Android\Sdk\cmdline-tools\latest\bin\\..
Caused by: java.lang.ClassNotFoundException: J\AppData\Local\Android\Sdk\cmdline-tools\latest\bin\\//

编辑1：

我尝试重新安装 sdk（从 appdata/android/sdk 完全删除文件后）。 它有点工作，但现在出现了新的错误。：

C:\Users\USER>flutter doctor --android-licenses
Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
        at com.android.repository.api.SchemaModule$SchemaModuleVersion.<init>(SchemaModule.java:156)
        at com.android.repository.api.SchemaModule.<init>(SchemaModule.java:75)
        at com.android.sdklib.repository.AndroidSdkHandler.<clinit>(AndroidSdkHandler.java:81)
        at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:73)
        at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:48)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        ... 5 more

Answer 1

After a lot of searching and a lot of diff types of error ranging from environmental variable errors and java errors, i just uninstalled android studio, java and flutter files deleted appdatas etc. and reinstalled it again now flutter doctors works fine.

我知道这不是一个好的解决方案，但如果一切都失败了，有人可以试试这个。 谢谢

Answer 2

The crux of this issue seem to be with spaces in the Android SDK path , eg if your user name on windows is "John Smith", it will fail to detect the android SDK. 解决方案是将'C:\Users\John Smith\AppData\Local\Android\Sdk' 移动到没有空格的路径，例如'C:\Android\Sdk'。 然后运行以下

flutter config --android-sdk "C:\Android\Sdk"

PS：对于显示“[,] Android Studio（未安装）”的相关问题，运行以下命令手动将其指向默认的 Android Studio 安装位置

flutter config --android-studio-dir "C:\Program Files\Android\Android Studio"