Ellipsis in JTextField
Hi
Can any one please help me to get ellipsis in JTextField , if the text is long and can't fit in JTextField . The text field is non-editable and should show characters from 1 and if it can't fit then it should show upto its size and show ellipsis indicating that it can't fit .
Please help me ASAP
That is a good idea, but my idea behind using text field is that i can set the number of columns not the size.So create a dummy textField using the number of columns you want. Then use getPreferredSize() to get the width of this text field. Now when you create all you JLabels you can set the width of each label.
Similar Messages
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Is there any known efficient methods of creating the JTextField or JTable-cell Button as like in Forte's Component Inspector window where you click on the property value field and the value is displayed just left of a small button labelled "..." ie: [some text field with value][...] also referred to as the "ellipsis" buttons, or will most answers to this question simply describe the layout of a JField-JButton combination? The action from clicking on the [...] button aligned right of the JTextField simply invokes or displays a larger input interface in which upon completion of the entered data, returns the input to the related JTextField.
Thanks to anybody for any help with this, and perhaps in return, I may be able to answer any non-gui java questions, or some not so unfamilliar GUI questions.Hello StanislavL and Lutianxiong,
I remember asking this question some time ago, and the time has come again for me to seek this functionality. I have finally achieved the functionality and thought I would post the answer for anybody else. I had not realized that I had recieved a solution/reply to my original question as I come here to post the answer, and in fact, my solution does appear to be very similiar to your reply, StanislavL. As for you, Lutianxiong and other seekers of this info, here is my solution with a JFileChooser style input for the 3rd column which only shows gif,jpg and png files:
<code>
------------- TableCellFileInput.java -------------------
public class TableCellFileInput extends javax.swing.JPanel {
private String extensions[];
public TableCellFileInput(String fileExtensions[]) {
extensions = fileExtensions;
self = this;
initComponents();
private void initComponents() {
valueField = new javax.swing.JTextField();
fileButton = new javax.swing.JButton();
setLayout(new java.awt.BorderLayout());
valueField.setText("jTextField1");
add(valueField, java.awt.BorderLayout.CENTER);
fileButton.setText("...");
fileButton.setMargin(new java.awt.Insets(0, 2, 0, 2));
fileButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
fileButtonActionPerformed(evt);
add(fileButton, java.awt.BorderLayout.EAST);
private void fileButtonActionPerformed(java.awt.event.ActionEvent evt) {
String filePath = valueField.getText();
if(filePath != null && filePath.length() > 0) {
filePath = new java.io.File(filePath).getParent();
javax.swing.JFileChooser chooser
= new javax.swing.JFileChooser(filePath);
chooser.setFileFilter(new ImageFilter());
int returnVal = chooser.showOpenDialog(this);
if(returnVal == javax.swing.JFileChooser.APPROVE_OPTION) {
valueField.setText(chooser.getSelectedFile().getAbsolutePath());
class ImageFilter extends javax.swing.filechooser.FileFilter {
public boolean accept(java.io.File f) {
if(f.isDirectory()) return true;
String fName = f.getName();
if(extensions != null) {
for(int i=0;i<extensions.length;i++) {
if(fName.endsWith(extensions[ i ])) return true;
return false;
public String getDescription() {
return DESCRIPTION;
class CustomCellEditor extends javax.swing.AbstractCellEditor
implements javax.swing.table.TableCellEditor {
public Object getCellEditorValue() {
return valueField.getText();
public java.awt.Component getTableCellEditorComponent(javax.swing.JTable table, Object value, boolean isSelected, int row, int column) {
System.out.println("fileEditor");
if(value == null) valueField.setText("");
else valueField.setText(value.toString());
return self;
public void setColumn(javax.swing.table.TableColumn column) {
column.setCellEditor(new CustomCellEditor());
private javax.swing.JButton fileButton;
private javax.swing.JTextField valueField;
private static final String DESCRIPTION = "Image File Filter";
private java.awt.Component self;
------------- TestTable .java -------------------
public class TestTable extends javax.swing.JFrame {
public TestTable() {
editorField = new javax.swing.JTextField();
String fileExts[] = {"gif","jpg","png"};
fileEditorField = new TableCellFileInput(fileExts);
initComponents();
javax.swing.table.TableColumn column
= jTable1.getColumn("Title 3");
fileEditorField.setColumn(column);
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null, null, "cats"},
{null, null, null, "dogs"},
{null, null, null, "mice"},
{null, null, null, "birds"}
new String [] {
"Title 1", "Title 2", "Title 3", "Title 4"
Class[] types = new Class [] {
java.lang.Object.class, java.lang.Object.class, java.lang.Object.class, java.lang.String.class
public Class getColumnClass(int columnIndex) {
return types [columnIndex];
jScrollPane1.setViewportView(jTable1);
getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
setBounds((screenSize.width-400)/2, (screenSize.height-300)/2, 400, 300);
private void exitForm(java.awt.event.WindowEvent evt) {
System.exit(0);
public static void main(String args[]) {
new TestTable().show();
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable jTable1;
private javax.swing.JTextField editorField;
private TableCellFileInput fileEditorField;
</code> -
Open and Close OnScreen Keyboard while focus gain on JTextField
Hi
I have a Jtextfield when ever I click on textfield I want to open OSK(On Screen Keyboard) of Windows 8 OS and windows 7.
I tried in below mentioned way to open and close in focus listener focusGained() and focusLost() but it is not working. could some body do needful.
Opening OSK:
builder = new ProcessBuilder("cmd /c " + sysroot + " /System32/osk.exe");
Closing Osk:
Runtime.getRuntime().exec("taskkill /f /im osk.exe");You need to start() the ProcessBuilder and you need to split the command like this:
builder = new ProcessBuilder("cmd", "/c", sysroot + " /System32/osk.exe");
builder.start();
And naturally you should wrap the call in a new Thread or use an ExecutorService to avoid EDT problems. -
My Ellipsis 8 can no longer detect my gym's wifi signal. Please help!
I used my Ellipsis 8 to watch Netflix over the open wifi signal at my gym for 2 months with no problem. One day I showed up and no signal was found. I went through all the trouble shooting steps all the way down to factory resets with no resolution. Called Verizon tech support and still nothing. They had me send them the tablet in a recovery box. One week later I have the tablet back and they said nothing was wrong with the unit. I went to the gym today and it still can not detect the signal. My Samsung phone picks up a very strong signal. No other people have reported a problem with wifi connection issues. Obviously Planet Fitness will not allow me to start messing with their router. Any suggestions would be GREATLY APPRECIATED!
I understand the importance of ensuring you are able to get connected to wifi michaeltatham. Allow us to get to the bottom of your tablet concerns. Have you recently installed any new software or new applications when it stopped connecting to the gym wifi? Have you tried to connect another device to your gym wifi?
Thank You,
MichelleS_VZW
Follow us on Twitter @VZWSupport
If my response answered your question please click the �Correct Answer� button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!! -
Displaying the results of an iterator in JTextfields.
Hi people,
I have got two methods which basically iterate through statements (forward and back).
However I have a separate class which is basically the GUI for my program. I want the user to be able to click the next button and it iterates through the list and displays the element in the list in the JTextField.
The problem I am having is that it will not display the element in the predefined fields, does anyone know how I can go about this? My code for my two methods is below:
public void MusicNext()
try
if(titerator==null)
titerator = iList.listIterator();
if(titerator.hasNext())
System.out.println(titerator.next());//Just prints out the iterator atm.
else
titerator = null;
MusicNext();
catch(ConcurrentModificationException ex)
titerator = iList.listIterator();
System.out.println("Iterator has been reset.");
public Music MusicNext(String pTitle)
Music tTitle = null;
boolean found = false;
Iterator it = iList.iterator();
if(it.hasNext() && !found)
tTitle = (Music) it.next();
found = tTitle.getTitle().equalsIgnoreCase(pTitle);
return tTitle;
public void MusicPrevious()
try
if(titerator==null)
titerator = iList.listIterator();
if(titerator.hasPrevious())
System.out.println(titerator.previous());//Just prints out the iterator atm.
else
titerator = null;
catch(ConcurrentModificationException ex)
titerator = iList.listIterator();
System.out.println("Iterator has been reset.");
catch(NoSuchElementException ex)
//titerator = iList.listIterator();
System.out.println("No such element.");
}I am pretty sure they shouldn't be void but should return an element, but I am really not sure what to return.
Many Thanks,
Rob.
(Sorry I posted this before but I left out alot of detail).Don't get or instantiate the iterator in often-called methods.
It should be get or instantiated as a class global field once and for all.
Your ListIterator is good for such treatment becuase it can be
freely scanned backward, while Iterator can't. -
Hello!
I'm puzzled with API docs:
public JTextField()
Constructs a new TextField. A default model is created, the initial string is null, and the number of columns is set to 0.
But when I read the textfield with textfield.getText I do not get a null Object but an empty String object, i.e(""). Why?Hmm, very curious.Yes it is, so I looked into it.
Perhaps the no-arugument constructor creates a default
Document with an empty string?You are correct sir. In a round about way a character array is created which consists of a single character, that being the null terminator. If your still curious, its done in the GapContent constructor. -
Can't Copy text unless console is opened before applet with JTextField
If an applet uses JTextFields, it is impossible to copy text from the console to the clipboard (or anywhere else) if the console is opened after the applet.
See http://demo.capmon.dk/~pvm/nocopy/nocopy.html for a working applet with source and class file to try it out on...
So if something bad has happened, and there are hints in the console e.g. a stack trace, it all has to be retyped by hand, since all Copy or export is impossible...
Does anyone know of a workaround for this? I'd like to be able to e.g. copy stack traces to bug reports.
Try these test cases:
* Close all browser windows. Open a browser and visit this page. After the page with this applet has loaded, then open the console with "Tools/Sun Java Console" (or "Tools/Web Development/Java Console" in Mozilla). Select some text in the console. There is no way to put this text on the clipboard; the "Copy" button doesn't work, and neither does CTRL+Insert, CTRL+C or anything else.
* Close all browser windows. Open a browser window no some non-java page and then open the console with "Tools/Sun Java Console" (or "Tools/Web Development/Java Console" in Mozilla). Then visit this page. Select some text in the console. Now the "Copy" button does work, enabling "export" of e.g. stack traces to other applicaitons e.g. email.
The difference is which is opened first: The console or the applet. If you look at the very rudimentary Java source code, it is the mere creation of a JTextField is what disables or breaks the Copy functionality.
I've tried this on Windows XP with IE 6.0 and Mozilla 1.3 and they behave exactly the same. The JVM is Sun's 1.4.2 and I've tried 1.4.1_02 also with the same behavior. I've also tried javac from both 1.4.2 and 1.4.1_01hey .. this seems like a bug.. can you please file a bug at
http://java.sun.com/webapps/bugreport
thanks... -
How to capture the event on changing focus from a JTextField?
Hi All,
I have got a problem...
I want to do something (say some sort of validations/calculations) when I change the focus by pressing tab from a JTextField. But I am not able to do that.
I tried with DocumentListener (jtf01.getDocument().addDocumentListener(this);). But in that case, it's calling the event everytime I ke-in something in the text field. But that's not what I want. I want to call that event only once, after the value is changed (user can paste a value, or even can key-in).
Is there any way for this? Is there any method (like onChange() in javascript) that can do this.
Please Help me...
Regards,
UjjalHi Michael,
I am attaching my code. Actual code is very large containing 'n' number of components and ActionListeners. I am attaching only the relevant part.
//more codes
public class PaintSplitDisplay extends JApplet implements ActionListener
JFrame jf01;
JPanel jp01;
JTextField jtf01, jtf02;
//more codes
public void start()
//more codes
jtf01 = new JTextField();
jtf01.setPreferredSize(longField);
jtf01.setFont(new Font("Courier new",0,12));
jtf01.setInputVerifier(new InputVerifier(){public boolean verify(JComponent input)
//more codes
System.out.print("updating");
jtf02.setText("updated value");
System.out.print("updated");
return true;
//more codes
jtf02 = new JTextField();
jtf02.setPreferredSize(mediumField);
jtf02.setEditable(false);
jp01.add(jtf02, gbc);
//more codes
jf01.add(jp01);
jf01.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf01.setVisible(true);
//more codes
public static void main(String args[])
PaintSplitDisplay psp = new PaintSplitDisplay();
psp.start();
public void actionPerformed(ActionEvent ae)
//more codes
}As you can see I want to update the second JTextField based on some calculations. That should happen when I change the focus from my frist JTextField. I have called jtf02.setText() method inside InputVerifier. But it's giving error...
Please suggest...
Ujjal -
A simple question really ... I have a JTextField that I would like to have the user exit from with TAB and get
the same action as if they had left the field with the
ENTER key, i.e., I'd like to be able to use the getText
method to retrieve what the user entered. Currently, with
no modifcations whatsoever to the JTextField, when I
invoke getText after the user leaves the field with a TAB,
getText returns NULL. I've tried just about everything,
but can't get any of it to work (removeKeyStrokeBinding(), extending JTextField, etc.).
Thanks in advance for any suggestions.As you have niticed this is not such a simple question at all.
After some experimentation I decided to make the enter key cause the text field to loose focus.
addKeyListener (new KeyAdapter()
public void keyPressed (KeyEvent evt)
int key = evt.getKeyCode();
if (key == KeyEvent.VK_ENTER)
transferFocus ();
Then give the text field a focus listener
class TextListener extends java.awt.event.FocusAdapter
public void focusLost (FocusEvent e)
// evalutate the text using getText()
Which gets the field's content, validates it and then save it in the appropriate place.
The advantage to this approach is the whole field edits are always done in the same place (the focus adapter), and the enter and tab actions appear the same to the user.
The disadvantage is that, unless you know the initial value, you won't be able to tell if the value has changed.
hope this helpds some.
Terry -
Getting values from a JTextField on a JPanel in another class
I have created a class which extends a JPanel and added a JTextField to it, which has an addActionListener for getting the values typed in the JTextField. I want to use the class created in another class and retrieve the values typed in the JTextField, so how do i go about that? I have the class created below so the problem is how to retrieve content of val[val] in another class?
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class TextFieldChooser extends JPanel{
int val;
public TextFieldChooser(String str){
val = 0;
setLayout(new FlowLayout());
add(new JLabel(str));
JTextField txtf = new JTextField(5);
txtf.addActionListener(new TextFieldListener());
add(txtf);
}//end constructor
private class TextFieldListener implements ActionListener{
public void actionPerformed(ActionEvent e) {
val = Integer.parseInt(e.getActionCommand());
}//end text field listener
public int getValue(){
return val;
}//classThe problem is which listener can be programmed to handle the event performed on the class TextFieldChooser in the other class?
I have created a class which extends a JPanel and
added a JTextField to it, which has an
addActionListener for getting the values typed in the
JTextField. I want to use the class created in
another class and retrieve the values typed in the
JTextField, so how do i go about that? I have the
class created below so the problem is how to retrieve
content of val[val] in another class?
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class TextFieldChooser extends JPanel{
int val;
public TextFieldChooser(String str){
val = 0;
setLayout(new FlowLayout());
add(new JLabel(str));
JTextField txtf = new JTextField(5);
txtf.addActionListener(new TextFieldListener());
add(txtf);
}//end constructor
private class TextFieldListener implements
s ActionListener{
public void actionPerformed(ActionEvent e) {
val = Integer.parseInt(e.getActionCommand());
}//end text field listener
public int getValue(){
return val;
}//class -
Reading values from JTextField and using them?
Hello,
I am trying to make a login screen to connect to an oracle database. Im pretty new to creaing GUI. I need help with reading the values from the JTextField and to be able to use them for my connection. So do I need to apply a listener? How do I go about doing that in this project. Thanks for any code or advice.
import java.util.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
import java.sql.*;
public class UserDialog
String databaseURL;
String driver;
String database;
String username;
String password;
String hostname;
String port;
UserDialog() {
getInfo();
static String[] ConnectOptionNames = { "Login", "Cancel" };
static String ConnectTitle = "Login screen";
public void getInfo() {
JPanel connectionPanel;
JLabel databaseURLLabel = new JLabel("Database URL: ", JLabel.LEFT);
JTextField databaseURLField = new JTextField("");
JLabel driverLabel = new JLabel("Driver: ", JLabel.LEFT);
JTextField driverField = new JTextField("");
JLabel databaseLabel = new JLabel("Database: ", JLabel.LEFT);
JTextField databaseField = new JTextField("");
JLabel usernameLabel = new JLabel("User Name: ", JLabel.LEFT);
JTextField usernameField = new JTextField("");
JLabel passwordLabel = new JLabel("Password: ", JLabel.LEFT);
JTextField passwordField = new JPasswordField("");
JLabel hostnameLabel = new JLabel("Host Name: ", JLabel.LEFT);
JTextField hostnameField = new JTextField("");
JLabel portLabel = new JLabel("Port: ", JLabel.LEFT);
JTextField portField = new JTextField("");
connectionPanel = new JPanel(false);
connectionPanel.setLayout(new BoxLayout(connectionPanel,
BoxLayout.X_AXIS));
JPanel namePanel = new JPanel(false);
namePanel.setLayout(new GridLayout(0, 1));
namePanel.add(databaseURLLabel);
namePanel.add(driverLabel);
namePanel.add(databaseLabel);
namePanel.add(usernameLabel);
namePanel.add(passwordLabel);
namePanel.add(hostnameLabel);
namePanel.add(portLabel);
JPanel fieldPanel = new JPanel(false);
fieldPanel.setLayout(new GridLayout(0, 1));
fieldPanel.add(databaseURLField);
fieldPanel.add(driverField);
fieldPanel.add(databaseField);
fieldPanel.add(usernameField);
fieldPanel.add(passwordField);
fieldPanel.add(hostnameField);
fieldPanel.add(portField);
connectionPanel.add(namePanel);
connectionPanel.add(fieldPanel);
// Connect or quit
databaseURL = databaseURLField.getText();
driver = driverField.getText();
database = databaseField.getText();
username = usernameField.getText();
password = passwordField.getText();
hostname = hostnameField.getText();
port = portField.getText();
int n = JOptionPane.showOptionDialog(null, connectionPanel,
ConnectTitle,
JOptionPane.OK_CANCEL_OPTION,
JOptionPane.PLAIN_MESSAGE,
null, ConnectOptionNames,
ConnectOptionNames[0]);
if (n == 0) {
System.out.println("Attempting login: " + username);
String url = databaseURL+hostname+":"+port+":"+database;
// load the JDBC driver for Oracle
try{
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection con = DriverManager.getConnection (url, username, password);
System.out.println("Congratulations! You are connected successfully.");
con.close();
System.out.println("Connection is closed successfully.");
catch(SQLException e){
System.out.println("Error: "+e);
else if (n == 1)
System.exit(0);
public static void main (String args []) {
UserDialog ud = new UserDialog();
}thanks again,
Jamesthe reason why you can't get the text is because you are reading the value before some actually inserts anything in any fields.
Here is what you need to do:
Create a JDialog/JFrame. Create a JPanel and set that panel as contentPane (dialog.setContentPane(panel)). Insert all the components, ie JLabels and JTextFields. Add two buttons, Login and Cancel to the panel as well. Now get the username and password field values using getText() inside the ActionListener of the Login.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class LoginDialog extends JDialog
String username, password;
public LoginDialog( ){
setTitle( "Login" );
JPanel content = new JPanel(new GridLayout(0, 2) ); // as many rows, but only 2 columns.
content.add( new JLabel( "User Name" ) );
final JTextField nameField = new JTextField( "" );
content.add( nameField );
content.add( new JLabel( "Password" ) );
final JTextField passField = new JTextField( "" );
content.add( passField );
JButton login = new JButton( "Login" );
login.addActionListener( new ActionListener(){
public void actionPerformed( ActionEvent ae ){
username = nameField.getText();
password = passField.getText();
// call a method or write the code to verify the username and login here...
content.add( login );
JButton cancel = new JButton( "Cancel" );
cancel.addActionListener( new ActionListener( ){
public void actionPerformed( ActionEvent ae ){
dispose(); // close the window or write any code that you want here.
content.add( cancel );
pack( ); // pack everything in the dialog for display.
show(); // show the dialog. -
Problem with focus and selecting text in jtextfield
I have problem with jtexfield. I know that solution will be very simple but I can't figure it out.
This is simplified version of situation:
I have a jframe, jtextfield and jbutton. User can put numbers (0-10000) separated with commas to textfield and save those numbers by pressing jbutton.
When jbutton is pressed I have a validator which checks that jtextfield contains only numbers and commas. If validator sees that there are invalid characters, a messagebox is launched which tells to user whats wrong.
Now comes the tricky part.
When user presses ok from messagebox, jtextfield should select the character which validator said was invalid so that user can replace it by pressing a number or comma.
I have the invalid character, but how can you get the focus to jtextfield and select only the character which was invalid?
I tried requestFocus(), but it selected whole text in jtextfield and after that command I couldn't set selected text. I tried with commands setSelectionStart(int), setSelectionEnd(int) and select(int,int).
Then I tried to use Caret and select text with that. It selected the character I wanted, but the focus wasn't really there because it didn't have keyFocus (or something like that).
Is there a simple way of doing this?textField.requestFocusInWindow();
textField.select(...);The above should work, although read the API on the select(...) method for the newer recommended approach on how to do selection.
If you need further help then you need to create a "Short, Self Contained, Compilable and Executable, Example Program (SSCCE)",
see http://homepage1.nifty.com/algafield/sscce.html,
that demonstrates the incorrect behaviour, because I can't guess exactly what you are doing based on the information provided.
Don't forget to use the "Code Formatting Tags",
see http://forum.java.sun.com/help.jspa?sec=formatting,
so the posted code retains its original formatting. -
Problem with PropertyChangeListener and JTextField
I'm having a problem with PropertyChangeListener and JTextField.
I can not seem to get the propertychange event to fire.
Anyone have any idea why the code below doesn't work?
* NewJFrame.java
* Created on May 15, 2005, 4:21 PM
import java.beans.*;
import javax.swing.*;
* @author wolfgray
public class NewJFrame extends javax.swing.JFrame
implements PropertyChangeListener {
/** Creates new form NewJFrame */
public NewJFrame() {
initComponents();
jTextField1.addPropertyChangeListener( this );
public void propertyChange(PropertyChangeEvent e) {
System.out.println(e);
/** 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.
private void initComponents() {
jTextField1 = new javax.swing.JTextField();
jScrollPane1 = new javax.swing.JScrollPane();
jFormattedTextField1 = new javax.swing.JFormattedTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jTextField1.setText("jTextField1");
getContentPane().add(jTextField1, java.awt.BorderLayout.NORTH);
jFormattedTextField1.setText("jFormattedTextField1");
jScrollPane1.setViewportView(jFormattedTextField1);
getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
pack();
* @param args the command line arguments
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame().setVisible(true);
// Variables declaration - do not modify
private javax.swing.JFormattedTextField jFormattedTextField1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextField jTextField1;
// End of variables declaration
}If you want to listen to changes in the textfield's contents you should use a DocumentListener and not a PropertyChangeListener:
http://java.sun.com/docs/books/tutorial/uiswing/events/documentlistener.html
And please use [co[/i]de] tags when you are posting code (press the code button above the message window). -
Memory problem with JTextFields
Hello,
I have a wierd problem with JTextField and the memory.
I need to fill a JPanel with different Components (including JTextFields), then do some calculation, remove the Components and filling the JPanel again.
When i so this too often my i get an OutOfMemory Exception. I narrowed to problem down and wrote a small sample program to demonstrate the problem.
When i call the method doIT (where the Panel is repeatedly filled) from the main-function everything works fine, but when it is called as a result from the GUI-Button-Event the memory for the JTextFields is not freed (even the call of the Garbage collector changes nothing)
When i only use JButtons to fill the Panel everything works fine.
Has anyone an idea why this problem occurs and how i can work around it?
[Edit] I tested it whith java 1.5.0_06, 1.5.0_11, 1.6.0_02
Thanks
Marc
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryUsage;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class MemoryTestDLG extends JDialog {
public MemoryTestDLG(Frame owner) {
// create Dialog with one Button that calls the testMethod
super(owner);
JButton b = new JButton("doIT ...");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
doIT();
setVisible(false);
getContentPane().add(b);
pack();
public void doIT() {
// Testmethod that fills a JPanel 20 times with Components and clears it
// again
JPanel p = new JPanel();
long memUse1 = 0;
long memUse2 = 0;
long memUseTemp = 0;
for (int count = 0; count < 20; count++) {
// Clear the panel
p.removeAll();
// Get memory usage before the task
Runtime.getRuntime().gc();
memUse1 = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage()
.getUsed();
// Fill Panel with components
for (int i = 0; i < 200; i++) {
// The Buttons seem to be released without any problem
p.add(new JButton("test" + Math.random()));
// JTextFields are not released when used from the dialog.
p.add(new JTextField("test " + Math.random()));
// get memory usage after the task
Runtime.getRuntime().gc();
memUseTemp = memUse2;
memUse2 = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage()
.getUsed();
// print Memory results
System.out.println("Memory Usage: " + f(memUse1) + " ->"
+ f(memUse2) + " [ Used:" + f(memUse2 - memUse1)
+ " ] [ Freed: " + f(memUseTemp - memUse1) + "]");
public String f(long m) // formats the output
String s = "" + m;
while (s.length() < 8)
s = " " + s;
return s;
public static void main(String[] args) {
MemoryTestDLG d = new MemoryTestDLG(null);
System.out
.println("------------------ Direct Call (all is OK) -------------------");
d.doIT(); // Memory is freed with every call to JPanel.removeAll()
System.out
.println("------------ Call from Dialog (memory is not freed) -------------");
// The Memory keeps blocked
d.setModal(true);
d.setVisible(true);
System.exit(0);
}Message was edited by:
marcvomorcThank you for your answer,
In this sample the programm does not run out of memory. But when you look at the output you see, that in the first run (direct call) the memory ist freed immediately when tha panel is cleared but in the second run (from the Button) the memory usage is getting bigger and bigger. Wenn you change the number of components to 2000 (4000)
// Fill Panel with components
for (int i = 0; i < 2000; i++) {
// The Buttons seem to be released without any problem
//... ...and use the default memory settings (69mb heap) the programm runns out of memory.
I get the following output:
------------------ Direct Call (all is OK) -------------------
Memory Usage: 445504 -> 8121016 [ Used: 7675512 ] [ Freed: -445504]
Memory Usage: 617352 -> 8114336 [ Used: 7496984 ] [ Freed: 7503664]
Memory Usage: 810488 -> 8491768 [ Used: 7681280 ] [ Freed: 7303848]
Memory Usage: 943704 -> 8114976 [ Used: 7171272 ] [ Freed: 7548064]
Memory Usage: 836760 -> 8505072 [ Used: 7668312 ] [ Freed: 7278216]
Memory Usage: 978352 -> 8114784 [ Used: 7136432 ] [ Freed: 7526720]
Memory Usage: 835552 -> 8498288 [ Used: 7662736 ] [ Freed: 7279232]
Memory Usage: 977096 -> 8114312 [ Used: 7137216 ] [ Freed: 7521192]
Memory Usage: 835640 -> 8498376 [ Used: 7662736 ] [ Freed: 7278672]
Memory Usage: 977296 -> 8115000 [ Used: 7137704 ] [ Freed: 7521080]
Memory Usage: 835392 -> 8504872 [ Used: 7669480 ] [ Freed: 7279608]
Memory Usage: 976968 -> 8115192 [ Used: 7138224 ] [ Freed: 7527904]
Memory Usage: 836224 -> 8501624 [ Used: 7665400 ] [ Freed: 7278968]
Memory Usage: 977840 -> 8115120 [ Used: 7137280 ] [ Freed: 7523784]
Memory Usage: 835664 -> 8498256 [ Used: 7662592 ] [ Freed: 7279456]
Memory Usage: 976856 -> 8114384 [ Used: 7137528 ] [ Freed: 7521400]
Memory Usage: 835784 -> 8502848 [ Used: 7667064 ] [ Freed: 7278600]
Memory Usage: 977360 -> 8114592 [ Used: 7137232 ] [ Freed: 7525488]
Memory Usage: 835496 -> 8502720 [ Used: 7667224 ] [ Freed: 7279096]
Memory Usage: 976440 -> 8115128 [ Used: 7138688 ] [ Freed: 7526280]
------------ Call from Dialog (memory is not freed) -------------
Memory Usage: 866504 -> 8784320 [ Used: 7917816 ] [ Freed: -866504]
Memory Usage: 7480760 ->14631152 [ Used: 7150392 ] [ Freed: 1303560]
Memory Usage: 14245264 ->22127104 [ Used: 7881840 ] [ Freed: 385888]
Memory Usage: 19302896 ->27190744 [ Used: 7887848 ] [ Freed: 2824208]
Memory Usage: 27190744 ->35073944 [ Used: 7883200 ] [ Freed: 0]
Memory Usage: 31856624 ->39740176 [ Used: 7883552 ] [ Freed: 3217320]
Memory Usage: 39740176 ->47623040 [ Used: 7882864 ] [ Freed: 0]
Memory Usage: 44410480 ->52293864 [ Used: 7883384 ] [ Freed: 3212560]
Memory Usage: 52293864 ->58569304 [ Used: 6275440 ] [ Freed: 0]
Memory Usage: 58569304 ->64846400 [ Used: 6277096 ] [ Freed: 0]
Exception occurred during event dispatching:
java.lang.OutOfMemoryError: Java heap spacewhen I outcomment the adding of the JButtons the amount of freed memory is 0 in the second run. So my guess is, that there is a problem with freeing the memory for the JTextFields.
Memory Usage: 447832 -> 6509960 [ Used: 6062128 ] [ Freed: 6332768]
Memory Usage: 722776 -> 6785632 [ Used: 6062856 ] [ Freed: 5787184]
------------ Call from Dialog (memory is not freed) -------------
Memory Usage: 468880 -> 6770240 [ Used: 6301360 ] [ Freed: -468880]
Memory Usage: 6770240 ->13016264 [ Used: 6246024 ] [ Freed: 0]
Memory Usage: 13016264 ->19297080 [ Used: 6280816 ] [ Freed: 0]
Memory Usage: 19297080 ->25570152 [ Used: 6273072 ] [ Freed: 0]
Memory Usage: 25570152 ->31849160 [ Used: 6279008 ] [ Freed: 0]
Memory Usage: 31849160 ->38124368 [ Used: 6275208 ] [ Freed: 0]
Memory Usage: 38124368 ->44402072 [ Used: 6277704 ] [ Freed: 0]
Memory Usage: 44402072 ->50677928 [ Used: 6275856 ] [ Freed: 0]
Memory Usage: 50677928 ->56955880 [ Used: 6277952 ] [ Freed: 0]
Memory Usage: 56955880 ->63232152 [ Used: 6276272 ] [ Freed: 0]
Exception occurred during event dispatching:
java.lang.OutOfMemoryError: Java heap spaceAdditionally the JPanel I am using is not displayed on the screen. It stays invisible the whole time, but i cannot work around that, because the calculation is depending on the values being in components on the JPanel)
Marc -
How to change background color of all JTextFields
Hi,
I have made the code below to show all properties available in UIDefaults.
Then, I would like to have the same behaviour that this Web Forum, that sets a yellow color in background of "Subject input text", when the user focus this field. I want this in my Swing apps, when user changes from a field to other. But I didn't find something like "TextField.focusBackground" to do this...
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enumkey.nextElement().toString() + " = " +
enumdef.nextElement().toString());
}I would like to set up colors in the beggining of my Swing app, something like this for all components:
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UIManager.put("PasswordField.focusBackground", java.awt.Color.YELLOW);
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