Is there a way to run or simulate running Java statements (kind of like IDLE - the Python GUI) without compiling and running the executable? I want to quickly test statement
You should be able to use Beanshell to do this:
http://www.beanshell.org/download.html
Your other alternative, if you're using Eclipse, is to make use of the scrapbook functionality:
http://help.eclipse.org/helios/index.jsp?topic=/org.eclipse.jdt.doc.user/tasks/task-create_scrapbook_page.htm