Anand Shrivastava

Dear friends,

I have installed java 7 on my machine. However, when i try to compile any servlet it is not able to locate any of the packages relating to servlets i.e. javax.servlet.* and javax.servlet.http.*.

I surfed the net and found that I need to have jsdk.jar. However, despite rummaging the net for an entire week, I could not find jsdk.jar. I was also directed to a page which says that I should download the servlet development kit, but the links provided in most of the pages on the net are old and redirect me to the oracle sun site, which does not have any such development kit. Now, it has become a nightmare for me to compile even a trifle servlet.

Kindly help,
Thanks in anticipation.

Anand.

Dear friends,

I am not able to read the data sent from a jsp as xml. The jsp which sends the data as xml is as under:

<%@ page import="Codes.*, java.util.*, java.sql.*"%> <% String code = request.getParameter("code"); Connection con = null; try { con = Connect.getConnection(); } catch (Exception e) { System.out.println("could not connect"); } String query = "select * from supplier where no="+code; try { Statement stmnt = con.createStatement(); ResultSet rs = stmnt.executeQuery(query); rs.first(); StringBuffer sb = new StringBuffer(); sb.append("<record>"); sb.append("<code>" + rs.getString("no") + "</code>"); sb.append("<name>" + rs.getString("name") + "</name>"); sb.append("<address>" + rs.getString("address") + "</address>"); sb.append("<phone>" + rs.getString("phone") + "</phone>"); sb.append("<mobile>" + rs.getString("mobile") + "</mobile>"); sb.append("<email>" + rs.getString("email") + "</email>"); response.setContentType("text/xml"); response.setHeader("Cache-Control", "no-cache"); response.getWriter().write(sb.toString()); } catch (Exception e) { System.out.println(e.getMessage()); } %>

And the relevant function of the receiving jsp which has to read this sent data is as under:

function editstateChanged() { if (xmlhttp.readyState == 4) { if(xmlhttp.status == 200) { alert("editing"); var record = req.responseXML.getElementsByTagName("record")[0]; for (loop = 0; loop < record.childNodes.length; loop++) { var firstName = record.getElementsByTagName("name")[0].nodeValue; alert(firstname); } } else { alert("Error during AJAX call editing. Please try again. Status -" + xmlhttp.status); } } }

However, I am not able to read the firstname and after giving the alert of editing, the script stops. Please help.

Dear friends,

Thanks a lot. I figured it out.
The URL is malformed
It was
var url="savesupplier.jsp"; url=url+"?name="+escape(name)+"?address="+escape(address)+"?telephone="+escape(phone)+"?mobile="+escape(mobile)+"?email="+escape(email) url=url+"&sid="+Math.random();

whereas, "&" should be used in place of "?" and it should be

var url="savesupplier.jsp"; url=url+"?name="+escape(name)+"&address="+escape(address)+"&telephone="+escape(phone)+"&mobile="+escape(mobile)+"&email="+escape(email) url=url+"&sid="+Math.random();

Thanks a lot friends.

Dear friends,

Kindly consider the following function:

<script type="text/javascript"> function validate() { message=""; appendError(checkEmpty("name")); appendError(checkEmpty("address")); appendError(checkEmpty("phone")); appendError(checkEmpty("mobile")); appendError(checkEmpty("email")); appendError(checkNumber("phone")); appendError(checkNumber("mobile")); appendError(checkEmail("email")); if (printError()) { return false; } else { var name = document.getElementById("name").value; var address = document.getElementById("address").value; var phone = document.getElementById("phone").value; var mobile = document.getElementById("mobile").value; var email = document.getElementById("email").value; /*SAVING THROUGH AJAX*/ xmlhttp=getXMLObject(); if (!xmlhttp) { alert ("Your browser does not support XMLHTTP!"); return; } var url="savesupplier.jsp"; url=url+"?name="+escape(name)+"?address="+escape(address)+"?telephone="+escape(phone)+"?mobile="+escape(mobile)+"?email="+escape(email) url=url+"&sid="+Math.random(); alert(url); xmlhttp.onreadystatechange=stateChanged; xmlhttp.open("GET",url,true); xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); xmlhttp.send(null); return true; } } function stateChanged() { if (xmlhttp.readyState == 4) { if(xmlhttp.status == 200) { alert("saved"); } else { alert("Error during AJAX call. Please try again. Status -" + xmlhttp.status); } } } function getXMLObject() //XML OBJECT { var xmlHttp = false; try { xmlHttp = new ActiveXObject("Msxml2.XMLHTTP") // For Old Microsoft Browsers } catch (e) { try { xmlHttp = new ActiveXObject("Microsoft.XMLHTTP") // For Microsoft IE 6.0+ } catch (e2) { xmlHttp = false // No Browser accepts the XMLHTTP Object then false } } if (!xmlHttp && typeof XMLHttpRequest != 'undefined') { xmlHttp = new XMLHttpRequest(); //For Mozilla, Opera Browsers } return xmlHttp; // Mandatory Statement returning the ajax object created } </script>

And the following jsp file which is used for saving in database only

<%@ page import="Codes.*, java.util.*" %> <% Supplier sup = new Supplier(); sup.setName(request.getParameter("name")); sup.setAddress(request.getParameter("address")); sup.setTelephone(Long.parseLong(request.getParameter("telephone").trim())); sup.setMobile(Long.parseLong(request.getParameter("mobile").trim())); sup.setEmail(request.getParameter("email")); sup.Save(); %>

However, the ajax is not working and the data is not getting saved and i get the status as 0. Please help.

Dear friends,

After lot of mind boggling the thing which worked was
before iterating over the rows for removal

I add the lne

partTbl.removeEditor();

and everything works now
I wonder why.

But thanks to the Almighty and you guys

That is why I have incremented rowdeleted to keep track of relative position of a row with respect to the loop after the row is deleted. The logic works pretty fine without that listener. As soon as I attach that listerner it starts giving bizarre result. I have even done that backward loop iteration. It also gives the same result. The problem is somewhere with the listener.

Dear friends,

I have a JTable called partTbl with DefaultTableModel. However, I have attached the following listener is attached to it:
partTbl.setCellSelectionEnabled(true); ListSelectionListener l = new ListSelectionListener() { @Override public void valueChanged(ListSelectionEvent e) { if (partTbl.editCellAt(partTbl.getSelectedRow(), partTbl.getSelectedColumn())) partTbl.getEditorComponent().requestFocus(); } }; partTbl.getSelectionModel().addListSelectionListener(l);

The above listener makes sure that whenever a user preses tab and the cell gets focus it automatically comes to the editing mode which was what I wanted.

However, when I try to remove a row this listener interferes with it and un-intended rows get deleted. This I have verified, because when I remove the above
listener, the following code for removing the rows works very well, which along with the listener gives bizarre results:

private void btnremove_purchasepanelMousePressed(java.awt.event.MouseEvent evt) { // TODO add your handling code here: int totalrows=partTbl.getModel().getRowCount(); int rowdeleted=0; for (int currow=0;currow<=totalrows-1;currow++) { // the ninth col. in the table holds a check box for the user which if selected means the row has to be deleted if (partTbl.getModel().getValueAt(currow-rowdeleted, 9).equals(true)) { ((DefaultTableModel)partTbl.getModel()).removeRow(currow-rowdeleted); rowdeleted++; } } }

I am posting the entire code for your convenience

package Screens; import Codes.*; import javax.swing.JOptionPane; /* * To change this template, choose Tools | Templates * and open the template in the editor. */ /* * supplierGui.java * * Created on Sep 7, 2011, 7:00:37 AM */ /** * * @author dk */ public class supplierGui extends javax.swing.JFrame { /** Creates new form supplierGui */ public supplierGui() { initComponents(); } /** This method is called from within the constructor to * initialize the form. * WARNING: Do NOT modify this code. The content of this method is * always regenerated by the Form Editor. */ @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code"> private void initComponents() { jLabel1 = new javax.swing.JLabel(); jLabel2 = new javax.swing.JLabel(); jLabel3 = new javax.swing.JLabel(); jLabel4 = new javax.swing.JLabel(); jLabel5 = new javax.swing.JLabel(); jLabel6 = new javax.swing.JLabel(); txtphone = new javax.swing.JTextField(); txtmobile = new javax.swing.JTextField(); txtemail = new javax.swing.JTextField(); jScrollPane1 = new javax.swing.JScrollPane(); txtareaaddress = new javax.swing.JTextArea(); btnsave = new javax.swing.JButton(); btncancel = new javax.swing.JButton(); filler1 = new javax.swing.Box.Filler(new java.awt.Dimension(0, 0), new java.awt.Dimension(0, 0), new java.awt.Dimension(32767, 32767)); jButton1 = new javax.swing.JButton(); jComboBox1 = new javax.swing.JComboBox(); setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE); setTitle("Entry Form"); setLocationByPlatform(true); setModalExclusionType(java.awt.Dialog.ModalExclusionType.TOOLKIT_EXCLUDE); jLabel1.setFont(new java.awt.Font("Tahoma", 1, 14)); jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER); jLabel1.setText("SUPPLIER"); jLabel1.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); jLabel2.setFont(new java.awt.Font("Tahoma", 0, 14)); jLabel2.setHorizontalAlignment(javax.swing.SwingConstants.CENTER); jLabel2.setText("Name"); jLabel3.setFont(new java.awt.Font("Tahoma", 0, 14)); jLabel3.setText("Address"); jLabel4.setFont(new java.awt.Font("Tahoma", 0, 14)); jLabel4.setText("Phone No."); jLabel5.setFont(new java.awt.Font("Tahoma", 0, 14)); jLabel5.setText("Mobile No."); jLabel6.setFont(new java.awt.Font("Tahoma", 0, 14)); jLabel6.setText("Email Address"); txtphone.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N txtphone.setText(" "); txtphone.setFocusAccelerator(' '); txtphone.setVerifyInputWhenFocusTarget(false); txtphone.addFocusListener(new java.awt.event.FocusAdapter() { public void focusGained(java.awt.event.FocusEvent evt) { txtphoneFocusGained(evt); } public void focusLost(java.awt.event.FocusEvent evt) { txtphoneFocusLost(evt); } }); txtmobile.setFont(new java.awt.Font("Tahoma", 0, 14)); txtmobile.setText(" "); txtmobile.addFocusListener(new java.awt.event.FocusAdapter() { public void focusLost(java.awt.event.FocusEvent evt) { txtmobileFocusLost(evt); } }); txtemail.setFont(new java.awt.Font("Tahoma", 0, 14)); txtemail.setText(" "); txtareaaddress.setColumns(20); txtareaaddress.setRows(5); jScrollPane1.setViewportView(txtareaaddress); btnsave.setText("Save"); btncancel.setText("Cancel"); btncancel.setActionCommand(""); jButton1.setText("More"); jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" })); javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); getContentPane().setLayout(layout); layout.setHorizontalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addContainerGap(610, Short.MAX_VALUE) .addComponent(btnsave) .addGap(18, 18, 18) .addComponent(btncancel) .addGap(18, 18, 18) .addComponent(jButton1) .addGap(38, 38, 38)) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addGap(452, 452, 452) .addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addGap(340, 340, 340)) .addGroup(layout.createSequentialGroup() .addGap(268, 268, 268) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addComponent(jLabel6) .addGap(159, 159, 159) .addComponent(txtemail, javax.swing.GroupLayout.DEFAULT_SIZE, 224, Short.MAX_VALUE)) .addGroup(layout.createSequentialGroup() .addComponent(jLabel5) .addGap(180, 180, 180) .addComponent(txtmobile, javax.swing.GroupLayout.DEFAULT_SIZE, 224, Short.MAX_VALUE)) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jLabel2) .addComponent(jLabel3) .addComponent(jLabel4)) .addGap(178, 178, 178) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jComboBox1, 0, 224, Short.MAX_VALUE) .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 224, Short.MAX_VALUE) .addComponent(txtphone, javax.swing.GroupLayout.DEFAULT_SIZE, 224, Short.MAX_VALUE)))) .addGap(106, 106, 106) .addComponent(filler1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(23, 23, 23)) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(19, 19, 19) .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(68, 68, 68) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING) .addComponent(jLabel2) .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(28, 28, 28) .addComponent(jLabel3)) .addGroup(layout.createSequentialGroup() .addGap(18, 18, 18) .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 113, javax.swing.GroupLayout.PREFERRED_SIZE))) .addGap(26, 26, 26) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel4) .addComponent(txtphone, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGap(18, 18, 18) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel5) .addComponent(txtmobile, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(18, 18, 18) .addComponent(jLabel6)) .addGroup(layout.createSequentialGroup() .addGap(26, 26, 26) .addComponent(txtemail, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))) .addGap(85, 85, 85) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(btnsave) .addComponent(btncancel) .addComponent(jButton1))) .addGroup(layout.createSequentialGroup() .addGap(182, 182, 182) .addComponent(filler1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))) .addContainerGap(17, Short.MAX_VALUE)) ); pack(); }// </editor-fold> private void txtphoneFocusLost(java.awt.event.FocusEvent evt) { // TODO add your handling code here: System.out.println("entered"); String result = Validation.Validate(txtphone.getText().trim(),"null"); if (result != null) { JOptionPane.showMessageDialog(rootPane, result); txtphone.requestFocusInWindow(); } } private void txtmobileFocusLost(java.awt.event.FocusEvent evt) { // TODO add your handling code here: String message = Validation.Validate(txtmobile.getText().trim(), "int"); if (message != null) { JOptionPane.showMessageDialog(rootPane, message); txtmobile.requestFocusInWindow(); } } private void txtphoneFocusGained(java.awt.event.FocusEvent evt) { // TODO add your handling code here: //txtphone.setText("0000000"); } /** * @param args the command line arguments */ public static void main(String args[]) { /* Set the Nimbus look and feel */ //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) "> /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */ try { for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) { if ("Nimbus".equals(info.getName())) { javax.swing.UIManager.setLookAndFeel(info.getClassName()); break; } } } catch (ClassNotFoundException ex) { java.util.logging.Logger.getLogger(supplierGui.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (InstantiationException ex) { java.util.logging.Logger.getLogger(supplierGui.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (IllegalAccessException ex) { java.util.logging.Logger.getLogger(supplierGui.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (javax.swing.UnsupportedLookAndFeelException ex) { java.util.logging.Logger.getLogger(supplierGui.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } //</editor-fold> /* Create and display the form */ java.awt.EventQueue.invokeLater(new Runnable() { public void run() { supplierGui sg = new supplierGui(); sg.setVisible(true); } }); } // Variables declaration - do not modify private javax.swing.JButton btncancel; private javax.swing.JButton btnsave; private javax.swing.Box.Filler filler1; private javax.swing.JButton jButton1; private javax.swing.JComboBox jComboBox1; private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; private javax.swing.JLabel jLabel3; private javax.swing.JLabel jLabel4; private javax.swing.JLabel jLabel5; private javax.swing.JLabel jLabel6; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JTextArea txtareaaddress; private javax.swing.JTextField txtemail; private javax.swing.JTextField txtmobile; private javax.swing.JTextField txtphone; // End of variables declaration }

I am using netbeans and I have written this code in netbeans txtphone focuslost event section. I think so far as over-riding etc. are concerned, netbeans must have handled those issues.
As I have written the code in txtphone focuslost event section, I think it should be invoked only when txtphone field looses focus.

So far as UI is concerned, even I found netbeans better than eclipse.

I noticed one more thing. When the message dialog box appears for the first time, and if you drag it, there lies an identical dialog box beneath it and one more beneath it. This makes me to think that three dialog boxes, one below the other, are being opened probably.

Dear friends,

Please see the following code

private void txtphoneFocusLost(java.awt.event.FocusEvent evt) { // TODO add your handling code here: String result = Validation.Validate(txtphone.getText().toString().trim(), "x"); if (result != null) { JOptionPane.showMessageDialog(rootPane, result); txtphone.requestFocusInWindow(); } }

Here, if the textfield is left empty, the result string is displayed and txtphone field gains focus. So far so good. But as soon as it gains focus it again automatically comes to this focuslost method thrice. I fail to understand, why this is happenning.

Please help

I really thank all of you guys for such an exhaustive discussion

Thanks.

I dont know much, but I wud suggest you to acquire as many certs as possible and keep your artillery afresh always.