我尝试为 Android 平台设置 Ionic+Cordova。我安装了 JDK、Android SDK 等，但运行时cordova requirements给出：
Requirements check results for android:
Java JDK: installed
Android SDK: installed true
Android target: not installed
cmd: Command failed with exit code 1 Error output:
Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
at com.android.repository.api.SchemaModule$SchemaModuleVersion.<initSchemaModule.java:156)
at com.android.repository.api.SchemaModule.<initSchemaModule.java:75)
at com.android.sdklib.repository.AndroidSdkHandler.<clinitAndroidSdkHandler.java:81)
at com.android.sdklib.tool.AvdManagerCli.run(AvdManagerCli.java:213)
at com.android.sdklib.tool.AvdManagerCli.main(AvdManagerCli.java:200)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:185)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)
... 5 more
Gradle: installed C:\Program Files\Android\Android Studio\gradle\gradle-3.2\bin\gradle