Develop Reference

Unable to append text from a separate class to a JTextArea - Java

I'm currently having trouble (as the title states) appending text to a JTextArea from a separate class (or thread).
Here is my code, since I don't know what's causing the problem. (note that I'm using the Netbeans generated code for my GUI):
Chat Box GUI:
public class ChatBoxGUI extends javax.swing.JFrame
{
/**
* Creates new form ChatBoxGUI
* #return
*/
public javax.swing.JTextArea getTextArea()
{
return inputOutputTextArea;
}
public void setLabels(java.net.SocketAddress address, int port) {
this.addressLabel.setText("IP Address: " +address);
this.portLabel.setText("Port: " +Integer.toString(port));
}
public ChatBoxGUI() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
startServerButton = new javax.swing.JButton();
connectServerButton = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
addressLabel = new javax.swing.JLabel();
portLabel = new javax.swing.JLabel();
outputTextField = new javax.swing.JTextField();
stopButton = new javax.swing.JButton();
jScrollPane2 = new javax.swing.JScrollPane();
inputOutputTextArea = new javax.swing.JTextArea();
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 100, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 100, Short.MAX_VALUE)
);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
startServerButton.setText("Start Server");
startServerButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
startServerButtonActionPerformed(evt);
}
});
connectServerButton.setText("Connect to Server");
connectServerButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
connectServerButtonActionPerformed(evt);
}
});
jLabel1.setFont(new java.awt.Font("Lucida Grande", 1, 14)); // NOI18N
jLabel1.setText("Isaac's Chat Box");
addressLabel.setText("IP Address:");
portLabel.setText("Port: ");
stopButton.setText("Stop");
stopButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
stopButtonActionPerformed(evt);
}
});
inputOutputTextArea.setEditable(false);
inputOutputTextArea.setColumns(20);
inputOutputTextArea.setRows(5);
jScrollPane2.setViewportView(inputOutputTextArea);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jScrollPane2)
.addComponent(outputTextField, javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(startServerButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(connectServerButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addComponent(addressLabel))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(stopButton)
.addGroup(layout.createSequentialGroup()
.addGap(6, 6, 6)
.addComponent(portLabel)))
.addGap(0, 18, Short.MAX_VALUE)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(startServerButton)
.addComponent(jLabel1)
.addComponent(stopButton))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(connectServerButton)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(addressLabel)
.addComponent(portLabel)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 168, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(outputTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 44, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
pack();
}// </editor-fold>
private void startServerButtonActionPerformed(java.awt.event.ActionEvent evt) {
CreateServerDialog createServerDialog = new CreateServerDialog(this, true);
createServerDialog.setVisible(true);
try {
Runnable serverClassRunnable = new ServerClass(createServerDialog.getPort());
Thread serverClassThread = new Thread(serverClassRunnable);
serverClassThread.start();
} catch (java.io.IOException e) {
e.printStackTrace();
}
}
private void connectServerButtonActionPerformed(java.awt.event.ActionEvent evt) {
}
private void stopButtonActionPerformed(java.awt.event.ActionEvent evt) {
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(ChatBoxGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ChatBoxGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ChatBoxGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ChatBoxGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new ChatBoxGUI().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JLabel addressLabel;
private javax.swing.JButton connectServerButton;
private javax.swing.JTextArea inputOutputTextArea;
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextField outputTextField;
private javax.swing.JLabel portLabel;
private javax.swing.JButton startServerButton;
private javax.swing.JButton stopButton;
// End of variables declaration
}
Create Server Dialog:
public class CreateServerDialog extends javax.swing.JDialog {
private int port; private boolean isValid = false; private java.awt.Frame parent;
public int getPort() {
return port;
}
/**
* Creates new form CreateServerDialog
*/
public CreateServerDialog(java.awt.Frame par, boolean modal) {
super(par, modal);
parent = par;
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
portInput = new javax.swing.JTextField();
okButton = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
jLabel1.setText("Enter Port:");
okButton.setText("Ok");
okButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
okButtonActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(okButton)
.addGap(0, 0, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(portInput)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1)
.addGap(0, 0, Short.MAX_VALUE)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(portInput, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(okButton))
);
pack();
}// </editor-fold>
private void okButtonActionPerformed(java.awt.event.ActionEvent evt) {
ErrorDialog errorDialog = new ErrorDialog(parent, true);
try {
port = Integer.parseInt(this.portInput.getText());
isValid = true;
} catch (NumberFormatException n) {
errorDialog.errorOccured(0);
isValid = false;
}
if (port <= 1024 || port > 65535) {
errorDialog.errorOccured(0);
isValid = false;
}
if (isValid == true) {
this.dispose();
}
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(CreateServerDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(CreateServerDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(CreateServerDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(CreateServerDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the dialog */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
CreateServerDialog dialog = new CreateServerDialog(new javax.swing.JFrame(), true);
dialog.addWindowListener(new java.awt.event.WindowAdapter() {
#Override
public void windowClosing(java.awt.event.WindowEvent e) {
System.exit(0);
}
});
dialog.setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JLabel jLabel1;
private javax.swing.JButton okButton;
private javax.swing.JTextField portInput;
// End of variables declaration
}
Server Class:
import java.io.*;
import java.net.*;
public class ServerClass implements Runnable
{
private final ServerSocket serverSocket;
public ServerClass(int port) throws IOException
{
serverSocket = new ServerSocket(port);
}
public void run()
{
ChatBoxGUI chatBoxGUI = new ChatBoxGUI();
try {
chatBoxGUI.getTextArea().append("\nSearching for client connection. \nPort: " +serverSocket.getLocalPort()); //this is the code that isn't working
Socket server = serverSocket.accept();
System.out.println();
chatBoxGUI.setLabels(server.getLocalSocketAddress(), serverSocket.getLocalPort()); //this also isn't working - but that's not the focus of this question
DataOutputStream out = new DataOutputStream(server.getOutputStream());
DataInputStream in = new DataInputStream(server.getInputStream());
chatBoxGUI.getTextArea().append("\nClient found! Connected with: " +server.getRemoteSocketAddress());
//note: this part isn't finished - but it doesn't need to be for that code to work
} catch (IOException e) {
e.printStackTrace();
}
}
}
I've tried to do research on the problem, and what I've found tells me that I have to use either invokeLater or invokeAndWait when running the code so that it runs in the EDT. And I have tried to implement this but it still doesn't seem to work:
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
chatBoxGUI.getTextArea().append("\nSearching for client connection. \nPort: " +serverSocket.getLocalPort());
}
});
Similar output to the terminal works completely fine, so it's definitely an issue with appending the text.
Any help would be appreciated, and thanks in advance.

You have multiple instances of the ChatBoxGUI class, so you are not updating the text area that is visible on the desktop.
So first you create the ChatBoxGUI class. Then when you click on a button you create the ServerClass. In the ServerClass you create a second instance of the ChatBoxGUI.
Don't create the second instance of the ChatBoxGUI class!!!
Instead, if you want to access variables in the ChatBoxGUI class then you need to:
pass a reference of the ChatBoxGUI class to the ServerClass
save this reference as an instance variable in the ServerClass
access this variable when you want to add text to the text area.

Without a more complete example, all I can do is link you to this question that has an answer for a similar issue.
Or you could try changing your approach from:
public javax.swing.JTextArea getTextArea()
{
return inputOutputTextArea;
}
To:
public void setTextArea(String textToAppend)
{
inputOutputTextArea.append(textToAppend);
}

How can I display a java frame using an itemListener? [duplicate]

I am trying to do a simple Jform and call it from another class.
I want to use this Jframe in a server client application, but I don't know how to open the JFrame class from another class.
Like user has to chose
1- to open Jframe.
2- To Exit.
So What am I doing wrong?
Below are the codes:
Jframe Class named Calculas.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* #author user
*/
public class Calculas extends javax.swing.JFrame {
/**
* Creates new form Calculas
*/
public Calculas() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
a1Text = new javax.swing.JTextField();
a2Text = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
answer = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, 97, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(87, 87, 87)
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(113, 113, 113)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton1)))
.addContainerGap(86, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(60, 60, 60)
.addComponent(jLabel1)
.addGap(34, 34, 34)
.addComponent(jButton1)
.addContainerGap(140, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int a;
a = Integer.parseInt(a1Text.getText()) + Integer.parseInt(a2Text.getText());
answer.setText("Answer" + a);
// TODO add your handling code here:
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Calculas().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField a1Text;
private javax.swing.JTextField a2Text;
private javax.swing.JLabel answer;
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
// End of variables declaration
}
Test Class named Test.java
public class Test extends JFrame {
public static void main(String args[])
{
Calculas CAL = new Calculas();
CAL.Calculus();
}
}

Forgive me if this is naive, as Im not anything of a Java programmer...
But isnt it just because you need to set visible?
Calculas CAL = new Calculas();
CAL.setVisible(true);

The constructor of Calculas doesn't show (setVisible) the frame.
If you want to interact with the Calculas class in this manner, you should also be calling CAL.setVisible(true)
Also, by convention, all Java instance variables, should start with a lower case character and use camelCase conventions

In it's current form of your code, you can call the main method of your Calculas class in Test class or move the code to the Test class.
Warning: Extending JFrame is not a good Idea.
First alternative: You don't need to extend JFrame in Test
public class Test{
public static void main(String args[])
{
Calculas.main(new String[0]);
}
}
You haven't mentioned in your question how you want to be able to chose close or open, in console or in another JFrame or something...
Second Alternative:
But If I were you I could do something like this: wrap the code for look and feel in a separate method and call this from Test' s main.
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* #author user
*/
public class Calculas extends javax.swing.JFrame {
/**
* Creates new form Calculas
*/
public Calculas() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
a1Text = new javax.swing.JTextField();
a2Text = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
answer = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, 97, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(87, 87, 87)
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(113, 113, 113)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton1)))
.addContainerGap(86, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(60, 60, 60)
.addComponent(jLabel1)
.addGap(34, 34, 34)
.addComponent(jButton1)
.addContainerGap(140, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int a;
a = Integer.parseInt(a1Text.getText()) + Integer.parseInt(a2Text.getText());
answer.setText("Answer" + a);
// TODO add your handling code here:
}
public static setNimbusFeel(){
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
}
// Variables declaration - do not modify
private javax.swing.JTextField a1Text;
private javax.swing.JTextField a2Text;
private javax.swing.JLabel answer;
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
// End of variables declaration
}
And test class like this:
public class Test{
public static void main(String args[])
{
Calculas cal=new Calculas();
//</editor-fold>
Calculas.setNimbusFeel();
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Calculas().setVisible(true);
}
});
}
}
Like this:

Here's an example of a basic structure you can use:
import java.awt.*;
import javax.swing.*;
class MyGui {
private JFrame window = new JFrame("This is the title");
public MyGui() {
initComponents();
window.setBounds(100, 50, 600, 400); //location, size
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
public void initComponents() {
Container cp = window.getContentPane();
cp.setLayout(new FlowLayout() );
cp.add(new JLabel("Hello world") );
}
}
public class MyProg {
private static void createAndShowGUI() {
new MyGui();
}
public static void main(String[] args) {
//Schedule a job for the event dispatch thread:
//creating and showing this application's GUI.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
And in separate files:
MyGui.java
import java.awt.*;
import javax.swing.*;
public class MyGui {
private JFrame window = new JFrame("This is the title");
public MyGui() {
initComponents();
window.setBounds(100, 50, 600, 400); //location, size
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
public void initComponents() {
Container cp = window.getContentPane();
cp.setLayout(new FlowLayout() );
cp.add(new JLabel("Hello world") );
}
}
MyProg.java
import javax.swing.*;
public class MyProg {
private static void createAndShowGUI() {
new MyGui();
}
public static void main(String[] args) {
//Schedule a job for the event dispatch thread:
//creating and showing this application's GUI.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

Calculas CAL = new Calculas();
CAL.Calculus();
maybe, CAL.Calculas(); I dont know java but I realized that, sorry about my english:)

Swing tutorial issue

I am trying to learn Swing in Java. Right now, I am on the first tutorial, which is a Celsius/Fahrenheit Temperature converter. Right now, the first tutorial program that I have written is not running correctly, and I cannot seem to find the issue.
Here is the code:
package learn;
public class CelsiusConverterGUI extends javax.swing.JFrame {
/**
* Creates new form CelsiusConverterGUI
*/
public CelsiusConverterGUI() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
tempTextField = new javax.swing.JTextField();
celsiusLabel = new javax.swing.JLabel();
convertButton = new javax.swing.JButton();
fahrenheitLabel = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("CelsiusConverter");
tempTextField.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
tempTextFieldActionPerformed(evt);
}
});
celsiusLabel.setText("Celsius");
convertButton.setText("Convert");
convertButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
convertButtonActionPerformed(evt);
}
});
fahrenheitLabel.setText("Fahrenheit");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(tempTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(celsiusLabel))
.addGroup(layout.createSequentialGroup()
.addComponent(convertButton)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(fahrenheitLabel)))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[]{convertButton, tempTextField});
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(tempTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 20, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(celsiusLabel))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(convertButton)
.addComponent(fahrenheitLabel))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
layout.linkSize(javax.swing.SwingConstants.VERTICAL, new java.awt.Component[]{convertButton, tempTextField});
pack();
}// </editor-fold>
private void tempTextFieldActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void convertButtonActionPerformed(java.awt.event.ActionEvent evt) {
//Parse degrees Celsius as a double and convert to Farhenheit.
int tempFahr = (int) ((Double.parseDouble(tempTextField.getText())) * 1.8 + 32);
fahrenheitLabel.setText(tempFahr + " Fahrenheit");
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(CelsiusConverterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(CelsiusConverterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(CelsiusConverterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(CelsiusConverterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new CelsiusConverterGUI().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JLabel celsiusLabel;
private javax.swing.JButton convertButton;
private javax.swing.JLabel fahrenheitLabel;
private javax.swing.JTextField tempTextField;
// End of variables declaration
}
And this is the output:
I don't understand what could have gone wrong; I did exactly what the tutorial told me to do! For reference, here's the tutorial.
http://docs.oracle.com/javase/tutorial/uiswing/learn/creatinggui.html
Thanks!

I've ran your code and it runs fine.
What Java have you installed?
I don't know NetBeans but does it build automatically? Some IDE's don't, so you might have to build your application explicitly.

How to take values from 10 textFields and using one button to output the choices into a textField or Area? (With code)

We're trying to design a set of Textfields where users can enter a value depending on how much quantity of the product they want. We have one button called checkout.
Basically, 2 classes, One called FoodDept (where all the textfields are and the checkout Button), and one called Checkout where there is a textfield or Area where i can output the choices or numbers the user indicated. That is basicallly all I need.
package shopping;
import java.util.*;
public class foodDept extends javax.swing.JFrame {
/**
* Creates new form foodDept
*/
int apple;
int banana;
double a = 0;
double b = 0;
public foodDept() {
initComponents();
apple=0;
banana=0;
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
appleLabel = new javax.swing.JLabel();
appleField = new javax.swing.JTextField();
backBtn = new javax.swing.JButton();
bananaLabel = new javax.swing.JLabel();
bananaField = new javax.swing.JTextField();
checkoutBtn = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
appleLabel.setText("Apple ($1.99):");
appleField.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
appleFieldActionPerformed(evt);
}
});
backBtn.setText("Back");
backBtn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
backBtnActionPerformed(evt);
}
});
bananaLabel.setText("Banana ($0.99):");
checkoutBtn.setText("jButton1");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(backBtn)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 152, Short.MAX_VALUE)
.addComponent(checkoutBtn))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addComponent(appleLabel)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(appleField))
.addGroup(layout.createSequentialGroup()
.addComponent(bananaLabel)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(bananaField, javax.swing.GroupLayout.PREFERRED_SIZE, 50, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(0, 0, Short.MAX_VALUE)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(appleLabel)
.addComponent(appleField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(bananaLabel)
.addComponent(bananaField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 59, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(backBtn)
.addComponent(checkoutBtn))
.addContainerGap())
);
pack();
}// </editor-fold>
private void backBtnActionPerformed(java.awt.event.ActionEvent evt) {
new dept().setVisible(true);
dispose();
}
void setApple(int a){
apple=a;
}
int getApple(){
return apple;
}
public double getTotal(){
return a+b;
}
private void appleFieldActionPerformed(java.awt.event.ActionEvent evt) {
}
public void checkoutBtnActionPerformed(java.awt.event.ActionEvent evt) {
try{
double priceOfapple = 1.99;
int quantity = Integer.parseInt(appleField.getText());
double totalamount = priceOfapple*quantity;
checkout.resultField.setText(totalamount);
}
b = Double.parseDouble(bananaField.getText());
foodList fL = new foodList(apple,banana);
if(a > 0){
a=a*1.99;
}
if(b > 0){
b=b*0.99;
}
new checkout().setVisible(true);
dispose();
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(foodDept.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(foodDept.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(foodDept.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(foodDept.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//ArrayList<Double> orderList = new ArrayList<Double>();//ARRAYYYYY
//here
//for(int x = 0; x<= orderList.size();x++){
//}
foodDept a = new foodDept();
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new foodDept().setVisible(true);
}
});
}
// Variables declaration - do not modify
public javax.swing.JTextField appleField;
private javax.swing.JLabel appleLabel;
private javax.swing.JButton backBtn;
private javax.swing.JTextField bananaField;
private javax.swing.JLabel bananaLabel;
public javax.swing.JButton checkoutBtn;
// End of variables declaration
}
**********************************************************************************
/*
* 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 shopping;
import java.util.ArrayList;
import shopping.foodDept;
import shopping.foodDept;
import shopping.foodDept;
/**
*
* #author Kevin
*/
public class checkout extends javax.swing.JFrame {
/**
* Creates new form checkout
*/
public checkout() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
backBtn = new javax.swing.JButton();
purchaseBtn = new javax.swing.JButton();
resultField = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
backBtn.setText("Back");
backBtn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
backBtnActionPerformed(evt);
}
});
purchaseBtn.setText("Purchase");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(resultField)
.addGroup(layout.createSequentialGroup()
.addComponent(backBtn)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 148, Short.MAX_VALUE)
.addComponent(purchaseBtn)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(resultField, javax.swing.GroupLayout.DEFAULT_SIZE, 89, Short.MAX_VALUE)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(purchaseBtn)
.addComponent(backBtn))
.addContainerGap())
);
pack();
}// </editor-fold>
private void backBtnActionPerformed(java.awt.event.ActionEvent evt) {
new foodDept().setVisible(true);
dispose();
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(checkout.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(checkout.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(checkout.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(checkout.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//for(int x = 0; x<= orderList.size();x++){
//resultField.setText(orderList.get(x));
//}
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new checkout().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton backBtn;
private javax.swing.JButton purchaseBtn;
public javax.swing.JTextField resultField;
// End of variables declaration
}

Before start, some off-topic advices:
Please read about Java Code
Conventions
and stick to them because they make your code more readable.
Try to make your GUI classes without using GUI builders and spend some time learning about Swing and writing your classes by your own hand. You'll learn lot of things that builder "hides" you and your code will be simpler and cleaner.
Every Swing application should have only one JFrame. Take a look to this topic: The Use of Multiple JFrames, Good/Bad Practice?
I suspect because of backBtn presence that you're trying to do a kind of wizard. If this is the case I'd suggest you take a look to CardLayout. There are plenty of examples in SO too.
Well the two classes needed are there, you just have to find out the way to communicate them. One approach would be passing a List<String> to the Checkout class so when the JTextArea is initialized it can take this list as data:
public class Checkout extends JDialog {
List<String> dataToBeDisplayed;
...
public void setDataToBeDisplayed(List<String> data) {
this.dataToBeDisplayed = data;
}
private void initComponents() {
JTextArea textArea = new JTextArea(20,30);
for(String line : dataToBeDisplayed) {
textArea.append(line + System.lineSeparator());
}
getContentPane().add(new JScrollPane(textArea));
}
}
The List must be set before the dialog becomes visible, just like this:
Checkout checkout = new Checkout(this, true);
checkout.setDataToBeDisplayed(data); // data must be created and populated before this call
checkout.setVisible(true);

How To Call JFrame from another Java class

I am trying to do a simple Jform and call it from another class.
I want to use this Jframe in a server client application, but I don't know how to open the JFrame class from another class.
Like user has to chose
1- to open Jframe.
2- To Exit.
So What am I doing wrong?
Below are the codes:
Jframe Class named Calculas.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* #author user
*/
public class Calculas extends javax.swing.JFrame {
/**
* Creates new form Calculas
*/
public Calculas() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
a1Text = new javax.swing.JTextField();
a2Text = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
answer = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, 97, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(87, 87, 87)
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(113, 113, 113)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton1)))
.addContainerGap(86, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(60, 60, 60)
.addComponent(jLabel1)
.addGap(34, 34, 34)
.addComponent(jButton1)
.addContainerGap(140, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int a;
a = Integer.parseInt(a1Text.getText()) + Integer.parseInt(a2Text.getText());
answer.setText("Answer" + a);
// TODO add your handling code here:
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Calculas().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField a1Text;
private javax.swing.JTextField a2Text;
private javax.swing.JLabel answer;
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
// End of variables declaration
}
Test Class named Test.java
public class Test extends JFrame {
public static void main(String args[])
{
Calculas CAL = new Calculas();
CAL.Calculus();
}
}

Forgive me if this is naive, as Im not anything of a Java programmer...
But isnt it just because you need to set visible?
Calculas CAL = new Calculas();
CAL.setVisible(true);

The constructor of Calculas doesn't show (setVisible) the frame.
If you want to interact with the Calculas class in this manner, you should also be calling CAL.setVisible(true)
Also, by convention, all Java instance variables, should start with a lower case character and use camelCase conventions

In it's current form of your code, you can call the main method of your Calculas class in Test class or move the code to the Test class.
Warning: Extending JFrame is not a good Idea.
First alternative: You don't need to extend JFrame in Test
public class Test{
public static void main(String args[])
{
Calculas.main(new String[0]);
}
}
You haven't mentioned in your question how you want to be able to chose close or open, in console or in another JFrame or something...
Second Alternative:
But If I were you I could do something like this: wrap the code for look and feel in a separate method and call this from Test' s main.
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* #author user
*/
public class Calculas extends javax.swing.JFrame {
/**
* Creates new form Calculas
*/
public Calculas() {
initComponents();
}
/**
* 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
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
a1Text = new javax.swing.JTextField();
a2Text = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
answer = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, 97, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(87, 87, 87)
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(113, 113, 113)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton1)))
.addContainerGap(86, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(a1Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(a2Text, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(answer, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(60, 60, 60)
.addComponent(jLabel1)
.addGap(34, 34, 34)
.addComponent(jButton1)
.addContainerGap(140, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int a;
a = Integer.parseInt(a1Text.getText()) + Integer.parseInt(a2Text.getText());
answer.setText("Answer" + a);
// TODO add your handling code here:
}
public static setNimbusFeel(){
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Calculas.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
}
// Variables declaration - do not modify
private javax.swing.JTextField a1Text;
private javax.swing.JTextField a2Text;
private javax.swing.JLabel answer;
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
// End of variables declaration
}
And test class like this:
public class Test{
public static void main(String args[])
{
Calculas cal=new Calculas();
//</editor-fold>
Calculas.setNimbusFeel();
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Calculas().setVisible(true);
}
});
}
}
Like this:

Here's an example of a basic structure you can use:
import java.awt.*;
import javax.swing.*;
class MyGui {
private JFrame window = new JFrame("This is the title");
public MyGui() {
initComponents();
window.setBounds(100, 50, 600, 400); //location, size
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
public void initComponents() {
Container cp = window.getContentPane();
cp.setLayout(new FlowLayout() );
cp.add(new JLabel("Hello world") );
}
}
public class MyProg {
private static void createAndShowGUI() {
new MyGui();
}
public static void main(String[] args) {
//Schedule a job for the event dispatch thread:
//creating and showing this application's GUI.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
And in separate files:
MyGui.java
import java.awt.*;
import javax.swing.*;
public class MyGui {
private JFrame window = new JFrame("This is the title");
public MyGui() {
initComponents();
window.setBounds(100, 50, 600, 400); //location, size
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
public void initComponents() {
Container cp = window.getContentPane();
cp.setLayout(new FlowLayout() );
cp.add(new JLabel("Hello world") );
}
}
MyProg.java
import javax.swing.*;
public class MyProg {
private static void createAndShowGUI() {
new MyGui();
}
public static void main(String[] args) {
//Schedule a job for the event dispatch thread:
//creating and showing this application's GUI.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

Calculas CAL = new Calculas();
CAL.Calculus();
maybe, CAL.Calculas(); I dont know java but I realized that, sorry about my english:)