Flutter - Android 许可证状态未知

Question

I've been looking around extensively to try and figure out why I continued getting this exception. I've seen similar issues, but none that could resolve my issue.

whenever I run flutter doctor This pops up:

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    X Android license status unknown.
    Try re-installing or updating your Android SDK Manager.
    See https://developer.android.com/studio/#downloads or visit visit
    https://flutter.dev/docs/get-started/install/windows#android-setup for detailed instructions.

I have checked and my environment variables are all set

Then when I type flutter doctor --android-licenses I get this error

Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
        at com.android.repository.api.SchemaModule$SchemaModuleVersion.<init>(SchemaModule.java:156)
        at com.android.repository.api.SchemaModule.<init>(SchemaModule.java:75)
        at com.android.sdklib.repository.AndroidSdkHandler.<clinit>(AndroidSdkHandler.java:81)
        at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:73)
        at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:48)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        ... 5 more

Can you please help, I am confused and anything would really help

Answer 1

I believe that flutter doctor --android-licenses simply invokes <ANDROID_HOME>/tools/bin/sdkmanager from Android SDK. sdkmanager is a small wrapper that finds JVM and starts java program.

The following line implies that Java 9+ is used to run the sdkmanager .

java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema

Unfortunately, sdkmanager is not capable to run on new Java versions. So there might be few solutions:

1. Set JAVA_HOME environment variable pointing to JDK 1.8 before running flutter doctor . Eg set JAVA_HOME=... on Windows or export JAVA_HOME=... on linux
2. Add missing libraries and get sdkmanager running on Java 11