Friendly advice appreciated with a small personal project (Beginner)

[Kristjan Toots]

Hello,
I decided to try to do something more or less pratical. I would appreciate some guidance like: What to keep in mind, what to look for, what books to dive into and so on - a friendly advice

Im currently going through CS106A course and finished LearnNowJava.com JavaSE: Objects, Classes and Constructors.

The Problem:
We have a small warehouse where each item has specific ID code glued to. We also have a barcode scanner (default compapility with windows7). I would like to create a simple Java program what looks something like this:




I'm grateful for your help. : )

[Wouter Oet]

Define use-cases and requirements.
Think about an architecture and domain model which can support the use-cases and requirements.
Build the application.

Of course this is very simple but it are the basic steps needed for application development.

[Kristjan Toots]

Wouter Oet I shall thank you for your reply.

I have worked on this application for a week now, but still, i feel that im doing everything wrong. I mean, I've got some parts working like I planned, but the code and structure seems awful.

To illustrate the task I try to achieve:
"We have a small "warehouse" where we have to sign out every peace of hardware we take. At the moment we have a simple excel spreadsheet with 3 columns. [ ID .... NAME .... DATE]."

I would like to know your oppinion how you would build the application. Roughly what classes, what methods inside those classes, logic and so on.

What I have so far:
1) Small login box. When correct password provided pops up another window like this with user field selected with correct personal name.
2) When pressed OK, data goes to SQL database tables.

What I have from coding perspective:
I have 3 classes with empty constructors: GUI, Main, mySQL. Main has empty constructor from GUI class and calls void buildLoginScreen(). buildLoginScreen sends the password to mySQL class where loginVerification returns true or false. When returned true the same method calls another void buildGUI() from GUI class. When pressed OK the same method calls mysql.setData from mySQL class.

They say that the best way to learn is by doing it. I would like to make it correctly, rather than: "it works, it's enough".