Jar files. HELP!!!

Question

Hi Im having trouble interacting with a database via an applet. I have to create a JAR file? Im highly confused on how to set up this an allow my class file to have the needed permission?
thanks

Answer 1

you don't need a JAR to make an applet contact a database, however you need the JDBC driver or use the JDBC-ODBC bridge..
this is a simple test applet I have created to add a record to a database table, it uses the mySQL JDBC driver...check it out:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;
public class AppletAlphabet extends JApplet implements ActionListener {
     JButton buttonOK = new JButton("Add Record");
     JTextField firstname = new JTextField();
     JTextField lastname = new JTextField();
     JTextField address = new JTextField();
     void buildConstraints(
          GridBagConstraints gbc,
          int gx,
          int gy,
          int gw,
          int gh,
          int wx,
          int wy) {
          gbc.gridx = gx;
          gbc.gridy = gy;
          gbc.gridwidth = gw;
          gbc.gridheight = gh;
          gbc.weightx = wx;
          gbc.weighty = wy;
     public void init() {
          JPanel pane = new JPanel();
          GridBagLayout gridbag = new GridBagLayout();
          GridBagConstraints constraints = new GridBagConstraints();
          pane.setLayout(gridbag);
          buildConstraints(constraints, 0, 0, 1, 1, 5, 40);
          constraints.fill = GridBagConstraints.NONE;
          constraints.anchor = GridBagConstraints.EAST;
          JLabel label1 = new JLabel("First Name: ", JLabel.LEFT);
          gridbag.setConstraints(label1, constraints);
          pane.add(label1);
          buildConstraints(constraints, 0, 1, 1, 1, 5, 40);
          constraints.fill = GridBagConstraints.NONE;
          constraints.anchor = GridBagConstraints.EAST;
          JLabel label2 = new JLabel("Last Name: ", JLabel.LEFT);
          gridbag.setConstraints(label2, constraints);
          pane.add(label2);
          buildConstraints(constraints, 0, 2, 1, 1, 5, 40);
          constraints.fill = GridBagConstraints.NONE;
          constraints.anchor = GridBagConstraints.EAST;
          JLabel label3 = new JLabel("Address: ", JLabel.LEFT);
          gridbag.setConstraints(label3, constraints);
          pane.add(label3);
          buildConstraints(constraints, 1, 0, 1, 1, 70, 40);
          constraints.fill = GridBagConstraints.HORIZONTAL;
          gridbag.setConstraints(firstname, constraints);
          pane.add(firstname);
          buildConstraints(constraints, 1, 1, 1, 1, 70, 40);
          constraints.fill = GridBagConstraints.HORIZONTAL;
          gridbag.setConstraints(lastname, constraints);
          pane.add(lastname);
          buildConstraints(constraints, 1, 2, 1, 1, 70, 40);
          constraints.fill = GridBagConstraints.HORIZONTAL;
          gridbag.setConstraints(address, constraints);
          pane.add(address);
          buildConstraints(constraints, 1, 3, 1, 1, 20, 40);
          constraints.fill = GridBagConstraints.HORIZONTAL;
          gridbag.setConstraints(buttonOK, constraints);
          pane.add(buttonOK);
          buttonOK.addActionListener(this);
          firstname.setText("");
          lastname.setText("");
          address.setText("");
          setContentPane(pane);
     public void actionPerformed(ActionEvent evt) {
          Object source = evt.getSource();
          if (source == buttonOK) {
               /*     System.out.println(
                         firstname.getText()
                              + ","
                              + lastname.getText()
                              + ","
                              + address.getText()
                              + "��");*/
               if ((firstname.getText().compareTo("") != 0)
                    && (lastname.getText().compareTo("") != 0)
                    && (address.getText().compareTo("") != 0))
                    addRecord();
               else {
                    JOptionPane.showMessageDialog(null, "All fields are required");
               //     System.out.println("all fields required");
     public void addRecord() {
          String query =
               "INSERT INTO TESTTABLE VALUES('"
                    + firstname.getText()
                    + "','"
                    + lastname.getText()
                    + "','"
                    + address.getText()
                    + "','zorro')";
          try {
               Class.forName("com.mysql.jdbc.Driver").newInstance();
               Connection conn =
                    DriverManager.getConnection(
                         "jdbc:mysql://127.0.0.1/testing?user=talal&password=pass");
               Statement st = conn.createStatement();
               st.executeUpdate(query);
               st.close();
               firstname.setText("");
               lastname.setText("");
               address.setText("");
          } catch (Exception ex) {
               JOptionPane.showMessageDialog(
                    null,
                    "Failed Operation:\n " + ex.getMessage());
}I hope it helps :)