to be clear, Silver does not convert Swift code to Java (Language) code. it compiles Swift code for the Java platform. You'd still be writing using the Swift syntax, but you'd be coding for Android and you're building Java (Platform) executables.
(i know rthis can get confusing, because "Java" is used both as a name for th language and for the platform).
You would write separate UI code for Android — probably using Android XML layout files, just as you would in Java.
Does that make sense?