One of the most frustrating and time-consuming tasks in Java is creating basic, ordinary UI. As in, windows, buttons, scroll bars, text fields, etc.
This is in stark contrast to, say, Microsoft Visual Basic / Visual Studio, where you can just drag and drop elements onto a form, and what you see is what you get. And when you double-click a button on your form, you get to the code which is executed when the button is clicked. In Java, if you want anything other than just the basics, you're going to have to do a lot of typing.
That is, unless, you are using the WindowBuilder Engine and Eclipse.