Java swing form does not open when launched from another class - java

I'm new to swing, and I'm trying to implement a simple GUI with one form (HospitalGUI.form). When I run the associated Java file (HospitalGUI.java) as main, the form is visible.
I want to be able to launch it from my controller so that either the GUI or a console interface can be selected. When my controller instantiates it, the code in the constructor is executed, but the form doesn't open.
Is there anything special or additional that needs to be done for a form to be opened by another Object?
I would greatly appreciate any help understanding this.
My GUI's main is
public static void main(String[] args) {
final int FRAME_WIDTH = 300;
final int FRAME_HEIGHT = 400;
JFrame frame = new JFrame("Hospital System");
frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
frame.setContentPane(new HospitalGUI().rootPanel);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
and the call in the controller is
HospitalGUI hospitalInterface = new HospitalGUI();

When I run the associated Java file (HospitalGUI.java) as main, the form is visible.
That is because you main() method creates the HospitalGUI class and a frame for the panel. Then you add the panel to the frame and make the frame visible.
and the call in the controller is
HospitalGUI hospitalInterface = new HospitalGUI();
When you just use the above statement that means the constructor of your class still essentilly needs to invoke all the code from the main() method to create a frame and add the panel to the frame and make the frame visible.
Since you didn't post all that code we can't guess what you are missing.
So in reality you need to change your design. You need two classes:
one class to create the panel you want to add to the frame. So you can add the panel to the frame created in the main() method.
the controller class. This class will be responsible for creating the frame and adding the panel to the frame.

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I created a frame and after that a Jtabbed pane placed in
after that 3 Jpannel added,like the one below .
JPanel admpnl = new JPanel();
tabbedPane.addTab("ADMIN AREA", null, admpnl, null);
my class with the name of Admin has been created ,I wanna try to add admpnl which is a kind of Jpanel to a class ,i already extends from Jpanel,but I dunno how to add "admpnl" to this class.
public class Admin extends JPanel {
}
Where is the code for the JPanel admpnl....null); located? Is it in the Admin class or part of another class?
The quiestion might make more sense if we see more of your code, but in the meantime, you cannot add admpnl to an Admin object because Admin is already a JPanel.
Instead, you may try to take all the code after JPanel admpnl = new JPanel(); and add it to the constructor for the Admin class so that all those JTabbedPanes get added to your Admin object when it gets created.

Passing from Jdialog to Jframe

I've created a JDialog, and passed my JFrame in with it.
for (int i = 0; i < digiProdRadioBtns.length; i++) {
if (digiProdCheck[i].isSelected()) {
ProdDialog a = new ProdDialog(digiPopup[i], frame, digiProductList.getProduct(counter), digiProductList);
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I've then tried to access the methods of the JFrame from within the JDialog, but cannot.
public class ProdDialog extends JDialog {
cdDialog = new JDialog(jFrame, true);
this.jframe = jFrame;
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I've read that what I'm trying to do is possible, any reason as to why it's not working for me?
JFrame and JDialog are top-level containers typically used as view components. In general, they don't communicate except to position a dialog relative to its parent frame. Instead, arrange for your views to communicate using a PropertyChangeEvent, as shown in this example. Having a separate model that contains a notional List<Product> will let you employ the pattern discussed here.
I'm missing a lot of context here, what is it that is not working for you?
I assume you are seeing an error on the jframe.newEmployee(); command saying that the method is undefined, if so then that is reasonable because the JFrame class does not have that method, if your class is class ProdJFrame and it extends JFrame and has that method, then you need to do ((ProdJFrame)jframe).newEmployee();

My GUI will not display when I hit run in NetBeans

When I select "run" in Netbeans, my GUI does not display. It just displays a box on the bottom of the screen that says "Build successful".
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package modelrange;
import javax.swing.DefaultBoundedRangeModel;
public class RangedModel extends javax.swing.JPanel {
DefaultBoundedRangeModel myModel;
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new RangedModel().setVisible(true);
}
});
}
/**
* Creates new form RangedModel
*/
public RangedModel() {
myModel = new DefaultBoundedRangeModel(123, 100, 0, 1000);
initComponents();
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/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
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*/
private void initComponents() {
This is just the automated netbeans code from the GUI builder (edited out for the post)
}
JPanel forms are not created with main methods, in GUI Builder, which you do need.
JPanel is not a top-level container, which you do need to run a Swing app.
A top-level container is, for instance, a JFrame. So you should have created a JFrame form instead of a JPanel form. When you do this in Netbeans GUI Builder, a main method will be provided for you.
A simple fix would be just to create a new JFrame form, then just drag and drop the JPanel form to the JFrame form, as seen here, get rid of the main method in your JPanel form, then run the JFrame form class.
You may also need to set/change the Main class to the new JFrame form you just created. You can that by looking at this answer
First of all, you are extending JPanel, it's wrong because as peeskillet wrote at points 2 and 3.
Kind of top-level container are:
JFrame : the window with the bar
JWindow : the window without bar
JDialog : the window usually used to create option window
So you have to extend one of them, probably the first.
Than in this top-level container you can create JPanel, one or more, everyone will be a container of another object which will be the contenent.
Morover, remember to setVisible every JPanel that you implement and also the top-level container.
Useful links:
icon in JButton is not shown at the running of the program, what could be?
Java Swing: multiple windows
What's the difference between the implements & extends keywords in Java
change JPanel to JFrame. It will work.
Follow path YourProject/packacge which your java file is in
then,
You can right click to your project then click from over there "run file".This worked for me.
If you work in NetBeans, after building, check that you are running the file you need from the project. To do this, press shift + F6

Display pop-up message window in Java?

I read about JDialogs and JOptionPane messages but I still can't get it to work. I have a GUI class that extends JFrame. All I want to do is have a popup at the beginning of my program which informs the user about a couple of things. In my main I create the following gui:
GUI g = new GUI();
Right after that I was to display the window. I have tried the following in the main method:
JOptionPane.showMessageDialog(g, "work?");
JOptionPane.showMessageDialog(frame, "work?"); //(frame was used in documentation example so I tried it)
I also tried to add the pop up into the GUI class with the following
JOptionPane.showMessageDialog(this, "work?"); //(I'm not exactly sure what the Frame Owner parameter is supposed to be, unless I'm confusing this with JDialog.)
In any case, how would I make this window appear? Every single one of the methods I tried compiled, and nothing happened.
public class GUI extends JFrame implements ActionListener{
private Container background;
private static buttons etc...
private static JLabel disp,edisp;
private static JTextArea info;
//setting up the GUI for my program, adding action listeners, I can post more if necessary
}
And then I have the main where I want to call the pop up window
public static void main(String[] args){
GUI g = new GUI();
JOptionPane.showMessageDialog(g,"Work?");
}
Make sure that these are called near the beginning, be it in the main method or not.
Also, try just setting the first parameter as null.
So it reads:
JOptionPane.showMessageDialog(null,"Work?");
Also, remember to import it!

Display a form from another class file

I have a running java GUI application right now in a single class file, in this application I have a button that when clicked it is used to instantiate and display a separate form from a different class file in the same project. I am confused with how I actually access this other .java file in order to instantiate and display the form from it. Hope you can help.
Thanks, Beef
How do you access any class file? JFrame, JPanel, JTextField are all examples of Java source code contained in separate files. You would use:
JFrame frame = new JFrame();
JPanel panel = new JPanel();
JTextField textField = new JTextField();
So to access your custom form your would use:
CustomForm form = new CustomForm();
As long as the class file is found on your classpath it should not be a problem.
If you are having compile or run time problems then you need to display the message so we can give further help.
I am somewhat new to Java but can't you just create another class that contains a GUI and then when you click on a JButton component you can just create an instance of that class.
if (clicked == myButton) then {
myGUIClass = new myGUIClass(); //if the GUI is in the constructors this will create
//the frame.
}
Then when you are finished with the JFrame or class then you should have a dispose() method that tidies up all of your files and exits the JFrame.
Best Regards,
Doug Deines Hauf
I think that creating a new form in Java is a bit easier than C# or Visual Basic. Basically you can just create another class and build your form in that class. Once your GUI is built then you can just create an instance of that method in another class to show the gui.
Such as:
if (ButtonClick == true) {
MyGui m = new myGui(...);
m.show
} else
//no GUI shown here
}
Or you can just create an anonymous class to instantiate the GUI.
new myGui(...);
The above would create an anonymous class but I think it is better coding practice to create an actual variable of the class and then to call some method parameter that will show the GUI.

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