Emacs and Java

[Bill Dengler <codeofdusk@xxxxxxxxxxx>]

Hello,
I’m from a Python and Shell Scripting background, but will be learning Java as part of a class this semester.
So far, I have the following questions:
How can I configure Emacs to (with one keystroke) run javac (Java compiler) on the currently displayed source file? Ideally, I should be able to step through compiler errors/warnings if any, and then run java (the bytecode interpreter) on the main class if compilation is successful, with standard input and output through an Emacs buffer.
Does Emacs have a package for handling imports? For example, if I write:
Scanner Foo=new Scanner(System.in);
I should be able to easily import java.util.Scanner.
Is there an accessible autocomplete package that works with Java? The com.example.some.package.with.really.long.ClassNames in Java are quite long, so autocomplete suggestions would be very helpful.

Thanks in advance,
Bill