Do not use APIs from the sun.* packages

The sun.* APIs are unsupported, JDK-internal APIs, and may go away at any time. The sun.misc.BASE64Encoder and sun.misc.BASE64Decoder have been removed in Java SE 11. Instead, use the supported java.util.Base64 class, which was added in Java SE 8. In addition, the sun.misc.Unsafe.defineClass class has been removed in Java SE 11. Instead, use the supported java.lang.invoke.MethodHandles.Lookup.defineClass class.

For more information, see the Removal and Future Removal of sun.misc and sun.reflect APIs, Class Base64 documentation and MethodHandles.Lookup documentation.