JAVA BASIC WINDOW

First I will show you how the base code for a java gui application is created. We will be creating a simple window with a button that will print text to the console.

1. Install Eclipse

   • Should already be installed, if not, download / install the latest from eclipse.org

2. Create a new Java Project

   • Locate FILE -> NEW -> Java Project
   • Name the project whatever you want, I simply named mine "JavaWindowTesting"
   • Click Finish

3. Create a package

   Unlike in Android studio, we need to create the file structure for java to run correctly. We need to create a new package to store our .java classes.

   • On the navigation view, open your project
   • Right click on the "src" (source) folder
   • Locate NEW -> PACKAGE
   • Name the package whatever you want, I named it "testing"

4. Create a class

   • Right click on your package and locate NEW -> Class
   • Name it whatever. I named it "WindowTesting"

5. Create the main method

   The java main method can be a bit confusing at times. Just memorize it and its much easier to deal with.

   • Add the code as follows:

     public static void main(String[] args){
     
     }
     

   The main method is used to start a java application. The computer will look for this method to start execution.

6. Create a JFrame (Java Window)

   In order to create a window in java, we need to use the built-in java API: Swing (More commonly known as JFrame)

   • Create a static Jframe (above the main method, not inside)

     public static JFrame frame;
     

   • Instantiate the frame under the main method. (Do not make another main, use the one we just made)

   • As an argument for Jframe, give it a String that will be the title of your window.

       public static void main(String[] args) {
     
        frame = new JFrame("A new window! :D");
     
        }
     

   • Set the bounds of the window (set the size it will appear on the screen)

        frame.setSize(640, 480);
     

   • Set the frame to be visible.

        frame.setVisible(true);
     

   • (Optional) Set frame layout to null. This fixes the issue of objects filling your screen instead of correctly positioning themselves.

        frame.setLayout(null);
     

7. Test your window. Press the green play button and choose Java Application.