我是因为androidstudio下载了新的版本太高，本地的java是1.8,不匹配导致的。升级是最好，但我正在项目开发中，还是先降级匹配java1.8的方式
- flutter doctor
Android license status unknown
- flutter doctor --android-licenses
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/android/sdklib/tool/sdkmanager/SdkManagerCli has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 52.0
请参考：stackoverflow.com/questions/6…
Uncheck Android SDK command-line Tools (latest)
Check Android SDK command-line Tools 8.0
Click Apply
In Windows, go to “C:\Users\USERNAME\AppData\Local\Android\Sdk\cmdline-tools” and rename the 8.0 folder to “latest”
Run Flutter doctor again.
