解决flutter doctor出现Android toolchain: Android license status unknown.

朱雀 2022-09-15 15:51 61阅读 0赞

### 文章目录 ###

*  问题描述
 *  解决方案

# 问题描述 #

使用`flutter doctor`检查开发环境，出现以下问题

wangyangyangdeMacBook-Pro:~ wangyang$ flutter doctor
    Doctor summary (to see all details, run flutter doctor -v):
    [✓] Flutter (Channel stable, 2.2.1, on Mac OS X 10.15.7 19H2 darwin-x64, locale
        zh-Hans-US)
    [!] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
        ✗ Android license status unknown.
          Run `flutter doctor --android-licenses` to accept the SDK licenses.
          See https://flutter.dev/docs/get-started/install/macos#android-setup for
          more details.
    [✓] Xcode - develop for iOS and macOS
    [✓] Chrome - develop for the web
    [✓] Android Studio (version 4.2)
    [✓] VS Code (version 1.61.0)
    [✓] Connected device (2 available)
    
    ! Doctor found issues in 1 category.

根据错误提示运行`flutter doctor --android-licenses`，出现以下Java异常。

wangyangyangdeMacBook-Pro:~ wangyang$ 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

`虽然这个错误不影响在Android上的编译和运行，但是本人是个强迫症，必须消灭掉！！！`

# 解决方案 #

根据上面的错误显示，猜测难道是Android SDK的问题？

打开Android Studio, Preferences-Appearance & Behavior- System Settings- Android SDK-SDK Tools

发现SDK的命令行工具没有安装。  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pe65LuU5aSn54mb_size_20_color_FFFFFF_t_70_g_se_x_16]

勾选，然后选择Apply，会出现安装提示.

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pe65LuU5aSn54mb_size_20_color_FFFFFF_t_70_g_se_x_16 1]  
点击OK，会出现安装进度。

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pe65LuU5aSn54mb_size_20_color_FFFFFF_t_70_g_se_x_16 2]

安装完成后，再次运行`flutter doctor`，已经没有错误了。OK 完美！

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pe65LuU5aSn54mb_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/66f11acca7f743daa6b4817881ffd651.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pe65LuU5aSn54mb_size_20_color_FFFFFF_t_70_g_se_x_16 1]: /images/20220828/f055ef25a4b74d27a194c0c0124f5a02.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pe65LuU5aSn54mb_size_20_color_FFFFFF_t_70_g_se_x_16 2]: /images/20220828/de655fa644e64cb69fbb6224049c2b25.png