What errors I have done?It shows the following for output for code:

String filePath = "C:/Users/omar/Desktop/myfolder/txtfile.txt"; File file = new File(filePath);

if (!file.exists()) { try { file.createNewFile(); } catch (IOException ex) { Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex); } }

BufferedWriter bw = null; FileWriter fw = null; try { fw = new FileWriter(file); bw = new BufferedWriter(fw);

for(int i = 0; i < jTableExport.getRowCount(); i++){//rows for(int j = 0; j < jTableExport.getColumnCount(); j++){//columns bw.write(jTableExport.getValueAt(i, j).toString()+" "); } bw.newLine(); } } catch (IOException ex) { Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex); } finally { try { if (bw != null) { bw.close(); } if (fw != null) { fw.close(); } } catch (IOException ex) { Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex); } }

output errors are

:Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at NewJFrame.jButtonExportActionPerformed(NewJFrame.java:167) at NewJFrame.access$100(NewJFrame.java:12) at NewJFrame$2.actionPerformed(NewJFrame.java:73) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) 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:6533) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6298) at java.awt.Container.processEvent(Container.java:2236) at java.awt.Component.dispatchEventImpl(Component.java:4889) at java.awt.Container.dispatchEventImpl(Container.java:2294) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466) at java.awt.Container.dispatchEventImpl(Container.java:2280) at java.awt.Window.dispatchEventImpl(Window.java:2746) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.awt.EventQueue$4.run(EventQueue.java:729) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)