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Spacing errors while printing vector to JTextArea

So I'm working on making a database system built on top of a Java Swing GUI... I have one button that works to add a person/thing to a vector (in this case the database):
// Database
Vector<String> db = new Vector<String>();
Here is the button's actionlistener to add:
new ActionListener() {
public void actionPerformed(ActionEvent e) {
String newStudent = student.getText();
db.addElement(newStudent);
This part all seems to be working fine, however, when I go to print out the vector on a JTextArea using a string buffer, there are odd spacing issues in the text on the JTextArea
Here is the StringBuffer and section where I print the vector onto the JTextArea:
StringBuffer dbb = new StringBuffer();
for (int i = 0; i < db.size(); i++) {
dbb.append(db.get(i) + '\n');
}
// printDB is the JTextArea
printDB.setText(dbb.toString());
add(printDB);
Screenshot of spacing issues:
Screenshot
Any Ideas on what might be causing this? The spacing seems to be linear as well (1space, 2spaces, 3spaces...)
Link to full project if needed (Sorry for bad code in general lol i'm just beginning): Full Code
Sorry if linear isn't the right word btw I couldn't think of another way to describe it
Code:
import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
import java.util.*;
import java.util.Vector.*;
import javax.swing.*;
public class Database extends JFrame implements ActionListener, EventListener {
// Database
Vector<String> db = new Vector<String>();
// Main Menu Buttons:
JButton addStudent = new JButton("Add Student");
JButton deleteStudent = new JButton("Delete Button");
JButton deleteAll = new JButton("Delete All Students");
JButton printAll = new JButton("Print Database");
JTextArea welcome = new JTextArea("Welcome!");
// Add Student Menu:
JTextField student = new JTextField();
JButton submit = new JButton("Add Student");
// Print Students
JTextArea printDB = new JTextArea();
JButton returnMenu = new JButton("Return to Menu");
public Database() {
super("DatabaseGUI");
setSize(800, 600);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(null);
setResizable(false);
welcome.setBackground(this.getForeground());
add(welcome);
welcome.setSize(60, 15);
welcome.setLocation(386, 300);
add(addStudent);
addStudent.setSize(150, 50);
addStudent.setLocation(25, 100);
add(deleteStudent);
deleteStudent.setSize(150, 50);
deleteStudent.setLocation(625, 100);
add(deleteAll);
deleteAll.setLocation(225, 100);
deleteAll.setSize(150, 50);
add(printAll);
printAll.setLocation(425, 100);
printAll.setSize(150, 50);
addStudent.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
welcome.setVisible(false);
addStudent.setVisible(false);
deleteStudent.setVisible(false);
deleteAll.setVisible(false);
printAll.setVisible(false);
add(student);
add(submit);
submit.setVisible(true);
submit.setSize(150, 30);
submit.setLocation(425, 250);
student.setVisible(true);
student.setSize(150, 30);
student.setLocation(275, 250);
submit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String newStudent = student.getText();
db.addElement(newStudent);
student.setText(null);
student.setVisible(false);
submit.setVisible(false);
welcome.setVisible(true);
addStudent.setVisible(true);
deleteStudent.setVisible(true);
deleteAll.setVisible(true);
printAll.setVisible(true);
}
});
}
});
printAll.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
welcome.setVisible(false);
addStudent.setVisible(false);
deleteStudent.setVisible(false);
deleteAll.setVisible(false);
printAll.setVisible(false);
StringBuffer dbb = new StringBuffer();
for (int i = 0; i < db.size(); i++) {
dbb.append(db.get(i) + '\n');
}
printDB.setText(dbb.toString());
add(printDB);
printDB.setSize(300, 400);
printDB.setEditable(false);
printDB.setLocation(100, 100);
printDB.setVisible(true);
add(returnMenu);
returnMenu.setVisible(true);
returnMenu.setSize(200, 30);
returnMenu.setLocation(500, 400);
returnMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
returnMenu.setVisible(false);
printDB.setVisible(false);
welcome.setVisible(true);
addStudent.setVisible(true);
deleteStudent.setVisible(true);
deleteAll.setVisible(true);
printAll.setVisible(true);
}
});
}
});
setVisible(true);
}
public static void main(String[] args) {
Database student = new Database();
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}

You're adding an ActionListener to the submit button repeatedly within the addStudent ActionListener, meaning as addStudent is pressed, more and more ActionListeners will be added to submit and this is not what you want.
Suggestions:
Add an ActionListener just once to your JButtons and not within other event listeners which may be called multiple times. Consider adding all ActionListeners within your class constructor.
Side recs:
Don't use absolute positioning and null layouts. While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't resize your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.
Learn how to use and then use CardLayout to allow you to cleanly and easily swap your views.
For example,
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
#SuppressWarnings("serial")
public class Database2 extends JPanel {
// constants for the cards
public static final String WELCOME = "welcome";
public static final String ADD_STUDENT = "add student";
public static final String DISPLAY_DATA = "display data";
private JTextArea displayTextArea = new JTextArea(15, 20);
private JTextField addStudentField = new JTextField(10);
private CardLayout cardLayout = new CardLayout();
private List<String> db = new ArrayList<>();
public Database2() {
// prepare JTextArea
displayTextArea.setWrapStyleWord(true);
displayTextArea.setLineWrap(true);
displayTextArea.setFocusable(false);
// set layout as CardLayout and add all JPanels with constants
setLayout(cardLayout);
add(createWelcomePanel(), WELCOME);
add(createAddStudentPanel(), ADD_STUDENT);
add(createDisplayDataPanel(), DISPLAY_DATA);
}
private JPanel createWelcomePanel() {
ShowStudentPanelAction showStudentAction = new ShowStudentPanelAction("Add Student");
DisplayDataAction displayDataAction = new DisplayDataAction("Display Data");
JButton addStudentButton = new JButton(showStudentAction);
JButton displayDataButton = new JButton(displayDataAction);
JPanel topPanel = new JPanel(new GridLayout(1, 0, 5, 0));
topPanel.add(addStudentButton);
topPanel.add(displayDataButton);
topPanel.add(new JButton(new ExitAction("Exit", KeyEvent.VK_X)));
JLabel welcomeLabel = new JLabel("Welcome", SwingConstants.CENTER);
// make JLabel text bigger
welcomeLabel.setFont(welcomeLabel.getFont().deriveFont(Font.BOLD, 42f));
// and give it a border 30 points wide
int ebGap = 30;
welcomeLabel.setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap,
ebGap, ebGap));
JPanel welcomePanel = new JPanel(new BorderLayout());
ebGap = 4;
welcomePanel.setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap, ebGap, ebGap));
welcomePanel.add(topPanel, BorderLayout.PAGE_START);
welcomePanel.add(welcomeLabel, BorderLayout.CENTER);
return welcomePanel;
}
private JPanel createAddStudentPanel() {
AddStudentAction addStudentAction = new AddStudentAction("Add Student");
addStudentField.setAction(addStudentAction);
JPanel addStudentPanel = new JPanel();
addStudentPanel.add(addStudentField);
addStudentPanel.add(new JButton(addStudentAction));
return addStudentPanel;
}
private JPanel createDisplayDataPanel() {
JPanel displayDataPanel = new JPanel();
JScrollPane scrollPane = new JScrollPane(displayTextArea);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
displayDataPanel.add(scrollPane);
displayDataPanel.add(new JButton(new ReturnToWelcomeAction("Return")));
return displayDataPanel;
}
private class ShowStudentPanelAction extends AbstractAction {
public ShowStudentPanelAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
cardLayout.show(Database2.this, ADD_STUDENT);
addStudentField.requestFocusInWindow();
addStudentField.selectAll();
}
}
private class DisplayDataAction extends AbstractAction {
public DisplayDataAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
StringBuilder sb = new StringBuilder();
for (String studentName : db) {
sb.append(studentName + "\n");
}
displayTextArea.setText(sb.toString());
cardLayout.show(Database2.this, DISPLAY_DATA);
}
}
private class AddStudentAction extends AbstractAction {
public AddStudentAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
String studentText = addStudentField.getText();
db.add(studentText);
cardLayout.show(Database2.this, WELCOME);
}
}
private class ReturnToWelcomeAction extends AbstractAction {
public ReturnToWelcomeAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
cardLayout.show(Database2.this, WELCOME);
}
}
private class ExitAction extends AbstractAction {
public ExitAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
Window window = SwingUtilities.getWindowAncestor(Database2.this);
if (window != null) {
window.dispose();
}
}
}
private static void createAndShowGui() {
Database2 mainPanel = new Database2();
JFrame frame = new JFrame("Database2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Reference clicked JButton inside ActionListener

I'm trying to write a Tic Tac Toe program using swing, but I seem to having some trouble. In my anonymous inner classes I attempt to set up the actionListener for each of my buttons, but I'm having trouble finding the type or the variable which will allow me to reference the buttons and set them to either X or Y. I tried e.getSource().setText() in my anonymous classes, but that came back with errors. Any thoughts?
Thanks!
Alex
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TicTacToe {
public JFrame frame;
public JLabel label;
public JPanel panel;
public static int counter;
public void go()
{
frame = new JFrame("TicTacToe");
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new JPanel();
panel.setLayout(new GridLayout(3,3,10,10));
frame.add(BorderLayout.CENTER, panel);
label= new JLabel("TIC TAC TOE");
frame.add(BorderLayout.NORTH, label);
;
JButton button1 = new JButton("Button 1");
JButton button2 = new JButton("Button 1");
JButton button3 = new JButton("Button 1");
JButton button4 = new JButton("Button 1");
JButton button5 = new JButton("Button 1");
JButton button6 = new JButton("Button 1");
JButton button7 = new JButton("Button 1");
JButton button8 = new JButton("Button 1");
JButton button9 = new JButton("Button 1");
button1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
}
});
button2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button7.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button8.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
button9.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
}
});
panel.add(button1);
panel.add(button2);
panel.add(button3);
panel.add(button4);
panel.add(button5);
panel.add(button6);
panel.add(button7);
panel.add(button8);
panel.add(button9);
frame.setVisible(true);
panel.setVisible(true);
}
public static void main(String[] args)
{
TicTacToe gui = new TicTacToe();
gui.go();
}
}

Remember, ActionListener can be used on a number of different types of components, so the source reference is generalized. You need to cast to back to the expected value
button9.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
Object source = e.getSource();
if (source instanceof JButton) {
JButton btn = (JButton)source;
// Go ahead and do what you like
}
}
});
While I know your ActionListener as it stands can pretty much guarantee that the source type of the Object will be a JButton, I never like blindly casting objects, but that's me

If you are receiving errors then you should post them but I am assuming it is because you aren't asserting that the source object is in fact a button. There are two straightforward solutions to what you are doing.
First is that since you are only adding one action listener to each button, you can assume that it is the object that the action event is referring to. Just note that the button either needs to be an instance variable or declared final:
button1.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e)
{
button1.setText("X/Y");
}
});
Second, which would fix the cause of your error, is by asserting that the ActionEvent source object is in fact a button. This is done by checking that the source is an instance of JButton:
button1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() instanceof JButton) {
((JButton) e.getSource()).setText("X/Y");
}
}
});

I went through and cleaned up your code a little bit. I'm not quite sure why your code had errors, but I didn't get any. I suggest, since you have common code, to reuse it like I did in an array. I also added a boolean to switch between players on each button click.
Lastly, I suggest setting up the JFrame in the constructor, or in a private method called by the constructor (more complex user interfaces might have a lot of code, and breaking it up is a good habit for maintainability of your code) like I showed below.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TicTacToe {
public static final boolean PLAYER_X = false;
public static final boolean PLAYER_O = true;
public static int counter;
private JFrame frame;
private JLabel label;
private JPanel panel;
private JButton[] buttons;
private boolean player;
public TicTacToe() {
frame = new JFrame("TicTacToe");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new JPanel();
panel.setPreferredSize(new Dimension(500, 500));
panel.setLayout(new GridLayout(3, 3, 10, 10));
frame.add(BorderLayout.CENTER, panel);
label = new JLabel("TIC TAC TOE");
frame.add(BorderLayout.NORTH, label);
/* Set the initial player turn to player X */
player = PLAYER_X;
/* Create the JButtons */
buttons = new JButton[9];
/* Loop through and set all of them up */
for (int i = 0; i < buttons.length; i++) {
buttons[i] = new JButton();
buttons[i].addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() instanceof JButton) {
((JButton)e.getSource()).setText(player ? "O" : "X"); /* Set button text */
player = !player; /* Switch turns */
}
}
});
/* Add all of the buttons to the panel. */
panel.add(buttons[i]);
}
/* Pack the frame to the contents. Basically a "fit to contents". */
frame.pack();
}
public void go() {
frame.setVisible(true);
panel.setVisible(true);
}
public static void main(String[] args) {
TicTacToe gui = new TicTacToe();
gui.go();
}
}

Why wont the submit button work on the GUI

I have created an ActionListener and the button but the button doesn't work.
The action listener is supposed to be integrated with the submit button, please help?
Code:
import javax.swing.*;
import javax.swing.event.DocumentListener;import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Executer {
private JLabel lblCommand;
private JTextField txtEnter;
private JButton btNext, btPrevious, btSubmit;
private JPanel panel;
public static void main(String[] args) {
new Executer();
}
public Executer() {
JFrame frame = new JFrame("Script Executer");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500,300);
frame.setVisible(true);
myPanel();
Text();
Fields();
Buttons();
frame.add(panel);
frame.setVisible(true);
}
public void myPanel() {
panel = new JPanel();
panel.setLayout(null);
}
public void Text() {
lblCommand = new JLabel("Enter Here");
lblCommand.setBounds(145, 100, 150, 20);
Font styleOne = new Font("Arial", Font.BOLD, 13);
lblCommand.setFont(styleOne);
panel.add(lblCommand);
}
public void Fields() {
txtEnter = new JTextField();
txtEnter.setBounds(230, 100, 120, 20);
panel.add(txtEnter);
}
public void Buttons() {
btNext = new JButton ("Next");
btNext.setBounds(300,215,100,20);
panel.add(btNext);
btPrevious = new JButton ("Previous");
btPrevious.setBounds(190,215,100,20);
panel.add(btPrevious);
btSubmit = new JButton("Submit");
btSubmit.setBounds(80,215,100,20);
panel.add(btSubmit);
btSubmit.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String userEntered = txtEnter.getText();
if(userEntered.equalsIgnoreCase("yes"))
{
//run your script
}
}
});
}
}

Your code appears fine.
Enter a print statement and you can see it is working.
btSubmit.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// here the click happend so you can check your Textfield
String userEntered = txtEnter.getText();
System.out.println("User enterd: " + userEntered);
if(userEntered.equalsIgnoreCase("yes"))
{
System.out.println("Entered Yes");
}
}
});

How to override windowsClosing event in JFrame

i'm developing a JFrame which has a button to show another JFrame. On the second JFrame i want to override WindowsClosing event to hide this frame but not close all the application. So i do like this:
On second JFrame
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
formWindowClosing(evt);
}
});
private void formWindowClosing(java.awt.event.WindowEvent evt) {
this.dispose();
}
but application still close when i click x button on the windows. why? can you help me?
I can't use
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
because i need to show again that JFrame with some information added in it during operations from first JFrame. So i init second JFrame with attribute visible false. if i use dispose i lose the information added in a second moment by the other JFrame. so i use
private void formWindowClosing(java.awt.event.WindowEvent evt) {
this.setVisible(false);
}
but it still continue to terminate my entire app.

don't create a new JFrame, for new container use JDialog, if you want to hide the JFrame then better would be override proper e.g DefaultCloseOperations(JFrame.HIDE_ON_CLOSE), method JFrame.EXIT_ON_CLOSE teminating current JVM instance simlair as calll for System.exit(int)
EDIT
but it still continue to terminate my entire app.
1) then there must be another issue, your code maybe call another JFrame or formWindowClosing <> WindowClosing, use implemented method from API
public void windowClosing(WindowEvent e) {
2) I'b preferred DefaultCloseOperations(JFrame.HIDE_ON_CLOSE),
3) use JDialog instead of JFrame
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ClosingFrame extends JFrame {
private JMenuBar MenuBar = new JMenuBar();
private static JFrame frame = new JFrame();
private static JFrame frame1 = new JFrame("DefaultCloseOperation(JFrame.HIDE_ON_CLOSE)");
private static final long serialVersionUID = 1L;
private JMenu File = new JMenu("File");
private JMenuItem Exit = new JMenuItem("Exit");
public ClosingFrame() {
File.add(Exit);
MenuBar.add(File);
Exit.addActionListener(new ExitListener());
WindowListener exitListener = new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
frame.setVisible(false);
/*int confirm = JOptionPane.showOptionDialog(frame,
"Are You Sure to Close this Application?",
"Exit Confirmation", JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null, null, null);
if (confirm == JOptionPane.YES_OPTION) {
System.exit(1);
}*/
}
};
JButton btn = new JButton("Show second JFrame");
btn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame1.setVisible(true);
}
});
frame.add(btn, BorderLayout.SOUTH);
frame.addWindowListener(exitListener);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.setJMenuBar(MenuBar);
frame.setPreferredSize(new Dimension(400, 300));
frame.setLocation(100, 100);
frame.pack();
frame.setVisible(true);
}
private class ExitListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
int confirm = JOptionPane.showOptionDialog(frame,
"Are You Sure to Close this Application?",
"Exit Confirmation", JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null, null, null);
if (confirm == JOptionPane.YES_OPTION) {
System.exit(1);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
ClosingFrame cf = new ClosingFrame();
JButton btn = new JButton("Show first JFrame");
btn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.setVisible(true);
}
});
frame1.add(btn, BorderLayout.SOUTH);
frame1.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame1.setPreferredSize(new Dimension(400, 300));
frame1.setLocation(100, 400);
frame1.pack();
frame1.setVisible(true);
}
});
}
}

Adding a New Code with no WindowListener part as explained by #JBNizet, the very right thing. The default behaviour just hides the window, nothing is lost, you simply have to bring it back, every value inside it will remain as is, below is the sample program for further help :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TwoFrames
{
private SecondFrame secondFrame;
private int count = 0;
private void createAndDisplayGUI()
{
JFrame frame = new JFrame("JFRAME 1");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
secondFrame = new SecondFrame();
secondFrame.createAndDisplayGUI();
secondFrame.tfield.setText("I will be same everytime.");
JPanel contentPane = new JPanel();
JButton showButton = new JButton("SHOW JFRAME 2");
showButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
secondFrame.tfield.setText(secondFrame.tfield.getText() + count);
count++;
if (!(secondFrame.isShowing()))
secondFrame.setVisible(true);
}
});
frame.add(contentPane, BorderLayout.CENTER);
frame.add(showButton, BorderLayout.PAGE_END);
frame.setSize(200, 200);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new TwoFrames().createAndDisplayGUI();
}
});
}
}
class SecondFrame extends JFrame
{
private WindowAdapter windowAdapter;
public JTextField tfield;
public void createAndDisplayGUI()
{
setLocationByPlatform(true);
JPanel contentPane = new JPanel();
tfield = new JTextField(10);
addWindowListener(windowAdapter);
contentPane.add(tfield);
getContentPane().add(contentPane);
setSize(300, 300);
}
}
Is this what you want, try this code :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TwoFrames
{
private SecondFrame secondFrame;
private void createAndDisplayGUI()
{
JFrame frame = new JFrame("JFRAME 1");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
secondFrame = new SecondFrame();
secondFrame.createAndDisplayGUI();
secondFrame.tfield.setText("I will be same everytime.");
JPanel contentPane = new JPanel();
JButton showButton = new JButton("SHOW JFRAME 2");
showButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
if (!(secondFrame.isShowing()))
secondFrame.setVisible(true);
}
});
frame.add(contentPane, BorderLayout.CENTER);
frame.add(showButton, BorderLayout.PAGE_END);
frame.setSize(200, 200);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new TwoFrames().createAndDisplayGUI();
}
});
}
}
class SecondFrame extends JFrame
{
private WindowAdapter windowAdapter;
public JTextField tfield;
public void createAndDisplayGUI()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
JPanel contentPane = new JPanel();
tfield = new JTextField(10);
windowAdapter = new WindowAdapter()
{
public void windowClosing(WindowEvent we)
{
setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
}
};
addWindowListener(windowAdapter);
contentPane.add(tfield);
getContentPane().add(contentPane);
setSize(300, 300);
}
}

You could avoid the listener completely and use
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
Note that the default value is HIDE_ON_CLOSE, so the behavior you want should be the default behavior. Maybe you registered another listener that exits the application.
See http://docs.oracle.com/javase/6/docs/api/javax/swing/JFrame.html#setDefaultCloseOperation%28int%29

It's hard to pinpoint exactly why you are experiencing the behavior stated without seeing a little more of the set-up code, however it may be due to defaultCloseOperation set to EXIT_ON_CLOSE.
Here's a link to a demo displaying the properties you are looking for although the structure is a bit different. Have a look: http://docs.oracle.com/javase/tutorial/uiswing/examples/components/FrameworkProject/src/components/Framework.java

How to set BackGround color to a divider in JSplitPane

I have created a divider in JSplitPane. I am unable to set the color of divider. I want to set the color of divider. Please help me how to set color of that divider.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SplitPaneDemo {
JFrame frame;
JPanel left, right;
JSplitPane pane;
int lastDividerLocation = -1;
public static void main(String[] args) {
SplitPaneDemo demo = new SplitPaneDemo();
demo.makeFrame();
demo.frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
demo.frame.show();
}
public JFrame makeFrame() {
frame = new JFrame();
// Create a horizontal split pane.
pane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
left = new JPanel();
left.setBackground(Color.red);
pane.setLeftComponent(left);
right = new JPanel();
right.setBackground(Color.green);
pane.setRightComponent(right);
JButton showleft = new JButton("Left");
showleft.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Container c = frame.getContentPane();
if (pane.isShowing()) {
lastDividerLocation = pane.getDividerLocation();
}
c.remove(pane);
c.remove(left);
c.remove(right);
c.add(left, BorderLayout.CENTER);
c.validate();
c.repaint();
}
});
JButton showright = new JButton("Right");
showright.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Container c = frame.getContentPane();
if (pane.isShowing()) {
lastDividerLocation = pane.getDividerLocation();
}
c.remove(pane);
c.remove(left);
c.remove(right);
c.add(right, BorderLayout.CENTER);
c.validate();
c.repaint();
}
});
JButton showboth = new JButton("Both");
showboth.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Container c = frame.getContentPane();
c.remove(pane);
c.remove(left);
c.remove(right);
pane.setLeftComponent(left);
pane.setRightComponent(right);
c.add(pane, BorderLayout.CENTER);
if (lastDividerLocation >= 0) {
pane.setDividerLocation(lastDividerLocation);
}
c.validate();
c.repaint();
}
});
JPanel buttons = new JPanel();
buttons.setLayout(new GridBagLayout());
buttons.add(showleft);
buttons.add(showright);
buttons.add(showboth);
frame.getContentPane().add(buttons, BorderLayout.NORTH);
pane.setPreferredSize(new Dimension(400, 300));
frame.getContentPane().add(pane, BorderLayout.CENTER);
frame.pack();
pane.setDividerLocation(0.5);
return frame;
}
}
Thanks
Sunil kumar Sahoo

Or, since the divider is a container, you can do the following:
dividerContainer = (BasicSplitPaneDivider) splitPane.getComponent(2);
Component leftBtn = dividerContainer.getComponent(0);
Component rightBtn = dividerContainer.getComponent(1);
dividerContainer.setBackground(Color.white);
dividerContainer.setBorder(BorderFactory.createEmptyBorder(0, 4, 0, 4));
dividerContainer.setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));
dividerContainer.add(toolbar);
dividerContainer.setDividerSize(toolbar.getPreferredSize().height);

This code works for me:
splitPane.setUI(new BasicSplitPaneUI() {
public BasicSplitPaneDivider createDefaultDivider() {
return new BasicSplitPaneDivider(this) {
public void setBorder(Border b) {
}
#Override
public void paint(Graphics g) {
g.setColor(Color.GREEN);
g.fillRect(0, 0, getSize().width, getSize().height);
super.paint(g);
}
};
}
});
splitPane.setBorder(null);
You can change divider color "g.setColor(new Color(R,G,B))".

This worked for me fine.First you are creating JFrame with it's normal methods such as setDefaultCloseOperation(), setBounds(), getContentPane(). Then create an object from your class then use that to call all the other methods through out the program, in this case I created object called app. One thing you have to keep in mind is that don't forget to use ActionListener e.
Also color changes must go with setBackground() function, while you getting the values from getSource() for the color change.
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class Main implements ActionListener {
private static void createAndShowGUI() {
Main app=new Main();
// make frame..
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("I am a JFrame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(20,30,300,120);
frame.setLayout(null);
//Create a split pane
JSplitPane myPane = new JSplitPane();
myPane.setOpaque(true);
myPane.setDividerLocation(150);
app.right = new JPanel();
app.right.setBackground(new Color(255,0,0));
app.left = new JPanel();
app.left.setBackground(new Color(0,255,0));
app.left.setLayout(null);
myPane.setRightComponent(app.right);
myPane.setLeftComponent(app.left);
// make buttons
app.butt1=new JButton("Red");
app.butt2=new JButton("Blue");
app.butt3=new JButton("Green");
// add and size buttons
app.left.add(app.butt1);
app.butt1.setBounds(10,10, 100,20);
app.left.add(app.butt2);
app.butt2.setBounds(10,30, 100,20);
app.left.add(app.butt3);
app.butt3.setBounds(10,50, 100,20);
// set up listener
app.butt1.addActionListener(app);
app.butt2.addActionListener(app);
app.butt3.addActionListener(app);
frame.setContentPane(myPane);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
// check which button and act accordingly
if (e.getSource()==butt1)
right.setBackground(new Color(255,0,0));
if (e.getSource()==butt2)
right.setBackground(new Color(0,0,255));
if (e.getSource()==butt3)
right.setBackground(new Color(0,255,0));
}
public static void main(String[] args) {
// start off..
try {
UIManager.setLookAndFeel(
"javax.swing.plaf.metal.MetalLookAndFeel" );
}
catch (Exception e)
{
System.out.println("Cant get laf");
}
Object a[]= UIManager.getInstalledLookAndFeels();
for (int i=0; i<a.length; i++)
System.out.println(a[i]);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
// application object fields
int clickCount=0;
JLabel label;
JButton butt1;
JButton butt2;
JButton butt3;
JPanel left;
JPanel right;
}