Develop Reference

exception thrown while using .txt in file name

I am trying to run the following code in which i have to save my file as .txt...but whenever I click on 'Save' button..it throws an exception..
Also i want to know how could I save the contents of my textarea line by line in the txt file (including \n).
Here is the code
try
{
int val = jfc.showSaveDialog(jf);
int x =0;
String line;
if(val == JFileChooser.APPROVE_OPTION)
{
File fs=jfc.getSelectedFile();
if(!fs.exists())
{
fs.createNewFile();
FileWriter fw=new FileWriter(fs.getAbsolutePath()+".txt");
BufferedWriter bf=new BufferedWriter(fw);
BufferedReader br = new BufferedReader(new StringReader(ja.getText()));
while((line= br.readLine())!=null)
{
x++;
if(line.charAt(x)=='\n')
fw.write('\n');
else
fw.write(line+"\n");
}
fw.close();
}
else
{
}
}
}
catch(Exception e2)
{
e2.printStackTrace();
JOptionPane.showMessageDialog(null,"Cannot save file");
}
java.lang.StringIndexOutOfBoundsException: String index out of range: 3
at java.lang.String.charAt(String.java:658)
at notepad$1.actionPerformed(notepad.java:100)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Change your current code from
while((line= br.readLine())!=null)
{
x++;
if(line.charAt(x)=='\n')
fw.write('\n');
else
fw.write(line+"\n");
}
to
while((line= br.readLine())!=null) {
fw.write(line+"\n");
}

You are checking the first char in the first line, the second char in the second line so on.
Try changing
if(line.charAt(x)=='\n')
to
if(line.endsWith('\\n'))
Also you should escape line ends. Use \\n instead of \n.

Null Pointer Error Swing and Database

Below is the code, Spent Hour trying to track where is error...
Code is much big... more then 45 Fields so more confused
Exception is `java.lang.NullPointerException`
code is
String Scholno=getScholarNo();
ScholarNo.setText(Scholno);
addstudent = cnn.prepareStatement ("Insert into student(
ScholarNo, Student_Name, Application_No, DateOfAdmission,
Fathers_Name, Gender, DOB, Address, Session, Contact_no, Email, Course,
Branch, Submitted_Documents, Nationality, GuardianName, GuardianContactNo,
GuardianAddress, High_School_name, HS_Year_of_passing, HS_Percentage,
HS_Board, Higher_secondary_Name, H_year_of_passing, H_percentage,
H_board, Graduation, G_year_of_passing, G_percentage, G_University,
Post_graduation, PG_year_of_passing, PG_percentage, PG_university,
mother_name, religion, category, semester, section, status,Photo) ;
values(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");
addstudent.setString(1,ScholarNo.getText());
addstudent.setString(2,StudentName.getText().trim());
addstudent.setString(3,AdmissionNo.getText().trim());
addstudent.setString(4,DateOfAdmission.getDate().toString());
addstudent.setString(5,FatherName.getText().trim());
addstudent.setString(6,Gender.getSelectedItem().toString().trim());
addstudent.setString(7, DOB.getDate().toString());
addstudent.setString(8,Address.getText().trim());
addstudent.setString(9,Session.getSelectedItem().toString());
addstudent.setString(10,ContactNo.getText().trim());
addstudent.setString(11,Email.getText().trim());
addstudent.setString(12,Course.getSelectedItem().toString().trim());
addstudent.setString(13,Branch.getSelectedItem().toString().trim());
addstudent.setString(14,DocumentSubmitted.getText().trim());
addstudent.setString(15,Nationality.getText().trim());
addstudent.setString(16,GuardianName.getText().trim());
addstudent.setString(17,GuardianContactNo.getText().trim());
addstudent.setString(18,GuardianAddress.getText().trim());
addstudent.setString(19,HS.getText().trim());
addstudent.setString(20,HSYOP.getText().trim());
addstudent.setString(21,HSPercentage.getText().trim());
addstudent.setString(22,HSBoard.getText().trim());
addstudent.setString(23,HSS.getText().trim());
addstudent.setString(24,HSSYOP.getText().trim());
addstudent.setString(25,HSSPercentage.getText().trim());
addstudent.setString(26,HSSBoard.getText().trim());
addstudent.setString(27,UG.getSelectedItem().toString().trim());
addstudent.setString(28,GYOP.getText().trim());
addstudent.setString(29,GPercentage.getText().trim());
addstudent.setString(30,GUniy.getText().trim());
addstudent.setString(31,PG.getSelectedItem().toString().trim());
addstudent.setString(32,PGYOP.getText().trim());
addstudent.setString(33,PGpercentage.getText().trim());
addstudent.setString(34,PGUniy.getText().trim());
addstudent.setString(35,MotherName.getText().trim());
addstudent.setString(36,Religion.getSelectedItem().toString().trim());
addstudent.setString(37,Category.getSelectedItem().toString().trim());
addstudent.setString(38,Semester.getSelectedItem().toString().trim());
addstudent.setString(39,Section.getSelectedItem().toString().trim());
addstudent.setString(40,Status.getSelectedItem().toString().trim());
addstudent.setBytes(41,person_image);
addstudent.executeUpdate();
} catch(Exception e) {
//e.printStackTrace();
JOptionPane.showMessageDialog(null, e);
}
Result of Stack
run:
java.lang.NullPointerException
at projectmanagment.frmStudentRegistration.btnupdateActionPerformed(frmStudentRegistration.java:895)
at projectmanagment.frmStudentRegistration.btnupdateActionPerformed(frmStudentRegistration.java:895)
at projectmanagment.frmStudentRegistration.access$300(frmStudentRegistration.java:25)
at projectmanagment.frmStudentRegistration$4.actionPerformed(frmStudentRegistration.java:563)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6516)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
at java.awt.Component.processEvent(Component.java:6281)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4872)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

It got solved, error was regarding date which gave me null pointer Error, will post another Question for its answer so others are also benifited having same trouble

synthesizer error in java

First time App work fine.But when I click "Speech" button for second time It make errors
java.lang.IllegalThreadStateException
at java.lang.Thread.start(Thread.java:684)
at com.sun.speech.freetts.jsapi.FreeTTSSynthesizer.handleAllocate(FreeTTSSynthesizer.java:98)
at com.sun.speech.engine.BaseEngine.allocate(BaseEngine.java:219)
at text2speech.GUI.speechFile(GUI.java:141)
at text2speech.GUI.jButton2ActionPerformed(GUI.java:159)
at text2speech.GUI.access$100(GUI.java:24)
at text2speech.GUI$2.actionPerformed(GUI.java:61)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
Here is the code.
public void speechFile(){
String context=jTextArea1.getText();
try
{
System.setProperty("freetts.voices","com.sun.speech.freetts.en.us.cmu_us_kal.KevinVoiceDirectory");
Central.registerEngineCentral("com.sun.speech.freetts.jsapi.FreeTTSEngineCentral");
Synthesizer synthesizer =Central.createSynthesizer(new SynthesizerModeDesc(Locale.US));
synthesizer.allocate();
synthesizer.resume();
synthesizer.speakPlainText(context, null);
synthesizer.waitEngineState(Synthesizer.QUEUE_EMPTY);
synthesizer.deallocate();
}
catch(IllegalArgumentException e)
{
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (AudioException e) {
e.printStackTrace();
} catch (EngineException e) {
e.printStackTrace();
}
}
The thing I don't understand is first it work fine.second time it makes errors.How to fix this.

I don't know much about this library or technique, but to me it seems odd that you would register the engine once for each use, and odd that you wouldn't reuse an existing synthesizer.
Have you tried creating the synthesizer once and using it twice?

to make the code read more than once, all you have to do to remove the synth.deallocate(); from your code, then you will be able to loop till you want.

Cannot find TopComponent with preferredID

I'm trying to run my simple java-program, but have a big problem.
It's connected with GUI. It can not show any created window. I attach stack-trace and one class.
#ConvertAsProperties(
dtd = "-//org.shop.viewer//ShopViewer//EN",
autostore = false
)
#TopComponent.Description(
preferredID = "ShopViewerTopComponent",
//iconBase="SET/PATH/TO/ICON/HERE",
persistenceType = TopComponent.PERSISTENCE_ALWAYS
)
#TopComponent.Registration(mode = "explorer", openAtStartup = false)
#ActionID(category = "Window", id = "org.shop.viewer.ShopViewerTopComponent")
#ActionReference(path = "Menu/Window" /*, position = 333 */)
#TopComponent.OpenActionRegistration(
displayName = "#CTL_ShopViewerAction",
preferredID = "ShopViewerTopComponent"
)
#Messages({
"CTL_ShopViewerAction=ShopViewer",
"CTL_ShopViewerTopComponent=ShopViewer Window",
"HINT_ShopViewerTopComponent=This is a ShopViewer window"
})
public final class ShopViewerTopComponent extends TopComponent {
public ShopViewerTopComponent() {
initComponents();
setName(Bundle.CTL_ShopViewerTopComponent());
setToolTipText(Bundle.HINT_ShopViewerTopComponent());
EntityManager entityManager = Persistence.createEntityManagerFactory("ShopLibraryPU").createEntityManager();
Query query = entityManager.createNamedQuery("Shops.findAll");
List<Shops> resultList = query.getResultList();
for (Shops c : resultList) {
jTextArea1.append(c.getTitle() +"dqwdqwdqwdqwd"+ "\n");
}
}
java.lang.IllegalStateException: Cannot find TopComponent with preferredID ShopViewerTopComponent, see IDE log for more details.
at org.openide.windows.OpenComponentAction.actionPerformed(OpenComponentAction.java:91)
at org.openide.awt.AlwaysEnabledAction$1.run(AlwaysEnabledAction.java:198)
at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:95)
at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:116)
at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99)
at org.openide.awt.AlwaysEnabledAction.actionPerformed(AlwaysEnabledAction.java:201)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
[catch] at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
I think that a misstake is in TopComponent-constructor.
Thanks a lot.

This problem "cannot find TopCoponent with preferredID..." happens frequently when a problem occurs before loading the TopComponent.
A simple example : you try to load something in the constructor that fails (at any depth).
This unexplicit message made me mad more than once !
Hope this helps.

Java Table Rendered

I have a swing table with 4 columns. String, boolean(checkbox), String, Button. I pass a button to it and I get string of the button which I knew was going to happen. So I go about setting up a custom table renderer to make it render the button but I'm getting an exception and I'm not sure what it's trying to tell me.
This is my rendered class:
JtableButtonRendereer implements TableCellRenderer {
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
JButton button = (JButton) value;
if (isSelected) {
button.setForeground(table.getSelectionForeground());
button.setBackground(table.getSelectionBackground());
} else {
button.setForeground(table.getForeground());
button.setBackground(UIManager.getColor("Button.background"));
}
return button;
}
}
And this is what I'm using to set the renderer
imageTable.getColumn("TwitterFeed").setCellRenderer(new JtableButtonRendereer());
And this is the error I'm getting:
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Identifier not found
at javax.swing.table.DefaultTableColumnModel.getColumnIndex(DefaultTableColumnModel.java:282)
at javax.swing.JTable.getColumn(JTable.java:2564)
at javaapplication17.NewJFrame.jButton1ActionPerformed(NewJFrame.java:187)
at javaapplication17.NewJFrame.access$000(NewJFrame.java:36)
at javaapplication17.NewJFrame$1.actionPerformed(NewJFrame.java:60)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:682)
at java.awt.EventQueue$3.run(EventQueue.java:680)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:696)
at java.awt.EventQueue$4.run(EventQueue.java:694)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:693)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
The error is coming from the line I set the new renderer. Suggestions?

From the stacktrace it seems there is no column with the identifier "TwitterFeed" in the table. Note that this is a case senstitive check.