Jframe Jpanel - display result while window opened - swing

Question

I am trying to display client details in window application using Jframe. Everything is fine except that clients needs to wait until the process completed to show the result in window(Jframe).
Is there a way to show result(Jpanel.add()) dynamically after set Jframe.setVisible(true);
Note : I am new to this code
code I tried :
JFrame frame = new JFrame();
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}});
JPanel panel = new JPanel();
frame.setVisible(true);
int y=100;
for (int i = 0; i < 10; i++) {
//connecting DB and fetching data #single loop may take 5 secs to complete the process
panel.add(new JLabel("Client"+i)).setBounds(50,y, 100, 30); //after added, this should display in opened window
y=y+20;
//connecting DB and fetching data
for(int clinetDetails=0;clinetDetails< 3;clinetDetails++) {
panel.add(new JLabel("ClientDetails"+clinetDetails)).setBounds(50,y, 100, 30);
y=y+20;
}
panel.add(new JLabel("Client :"+i+" Completed")).setBounds(50,y, 100, 30);
y=y+20;
// frame.pack();
}
panel.setLayout(new GridLayout(0, 1));
JScrollPane scrollPane = new JScrollPane(panel);
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
frame.setPreferredSize(new Dimension(300, 300));
frame.pack();

Answer 1

You should probably use a SwingWorker, but this will give you an idea.
First you should do swing work on the EDT, so we start by creating the GUI.
static public void main(String[] args){
EventQueue.invokeLater( ()->createGui());
}
static public void createGui(){
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
frame.setVisible(true);
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
JScrollPane scrollPane = new JScrollPane(panel);
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
frame.setPreferredSize(new Dimension(300, 300));
frame.pack();
Runnable r = ()->{
for (int i = 0; i < 10; i++) {
//connecting DB and fetching data #single loop may take 5 secs to complete the process //all of the swing work should be done on the EDT.
final String clientName = "Client"+i;
EventQueue.invokeLater( ()->{
panel.add(new JLabel( clientName ));
} );
//connecting DB and fetching data
for(int clinetDetails=0;clinetDetails< 3;clinetDetails++) {
String clientD = "ClientDetails "+clinetDetails;
EventQueue.invokeLater( ()->{
panel.add(new JLabel(clientD));
panel.add(new JLabel( clientName + " Completed" ) );
});
}
}
};
new Thread(r).start(); //starts the working thread.
}
This will start a gui, and then when the new thread starts, you'll free up the edt so that java can display your gui, then as new information is produced, it updates the gui by posting an even to the EDT.