Problems in removing records from database of jList

Question

Hello I have the problem.. can anyone give me snippet? i have the table of MySql that display JList item so I can add the item easily but can't remove it from database? while pressing remove item?

I searched a lot no one has ever need of doing.. i wonder how its possible?

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                             
     try {
         Class.forName("com.mysql.jdbc.Driver");  
         Connection con= (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","ubuntu123");   

         PreparedStatement stmt = null;
         ResultSet rs =  null;

         String [] data;
         data = new String[100];
         int i=0;

         DefaultListModel listmodel = (DefaultListModel) jList2.getModel();
         int selectedIndex = jList2.getSelectedIndex();
         if (selectedIndex != -1) {
             listmodel.remove(selectedIndex);

             String query = "delete from supplierinfo where companyname = ?";
             stmt = (PreparedStatement) con.prepareStatement(query);
             stmt.setInt(1, i);
             stmt.execute();

             con.close();

             // i= i+1;
         }
    } catch(Exception e) {
        System.out.println("3rd catch " +e);
    }
}                                        

Answer 1

Use the ListModel#getElementAt(int) method with the currently selected index.

If you are certain your model only contains String instances, you can directly cast it to a String, then replace i with this string in stmt.setInt(1, i);

Answer 2

You can save element in a variable when you remove it from ListModel.

After that you can get all important info about this item and use it in your query.

Use something like this:

YourObjectType obj = (YourObjectType) listmodel.remove(selectedIndex);

String query = "delete from supplierinfo where companyname = ?";
                    stmt = (PreparedStatement) con.prepareStatement(query);
                    stmt.setInt(1, obj.getCompanyName());
                    stmt.execute();