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Close to having database queries displayed to Jlist, what am I missing?

Posted on 2016-09-28
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Last Modified: 2016-09-30
Hello, I feel like I may be very close to having my app display the rows from my database in the Jlist the way I would like (with every column from each row  displayed as one item on the Jlist. I think the problem might be in connecting the jList variable to the model(the jlist is called jList1), OR because of the fact that the jlist auto populated with items (item1, item2) etc, which I have not yet tried to remove. Do these have to be removed before I could expect it to work? Any help is greatly appreciated!....... it looks like:

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                        
       
        DefaultListModel<String> model = new DefaultListModel<>();
        JScrollPane pane = new JScrollPane(jList1);
        jList1.setModel(model);
        String sqlQuery = "select Column1, Column2, Column3, Column4, Column5 from APP.DATA123 " +
"where (Column1 = ?) AND (Column2 = ?) AND (Column3 = ?) OR (Column1 = ?) AND (Column2 = ?)";

                         

            String abc = jTextField2.getText();
            String cba = (String)jComboBox1.getSelectedItem();
            String cab = (String)jComboBox2.getSelectedItem();
            String data = "jdbc:derby://localhost:1527/sample";
        try (
              Connection conn = DriverManager.getConnection(
              data, "app", "app");
              PreparedStatement st = conn.prepareStatement(sqlQuery))   {
         
          Class.forName("org.apache.derby.jdbc.ClientDriver");
          st.setString(1, abc);
          st.setString(2, cba);
          st.setString(3, cab);      
          st.setString(4, cba);
          st.setString(5, cab);
          ResultSet rec = st.executeQuery();
         
           final String SPACE = " ";
           StringBuilder sBuilder = new StringBuilder();
           
            while (rec.next())  {
             sBuilder.setLength(0);
             sBuilder.append(rec.getString("Column1")).append(SPACE);
             sBuilder.append(rec.getString("Column2")).append(SPACE);
             sBuilder.append(rec.getString("Column3")).append(SPACE);
             sBuilder.append(rec.getString("Column4")).append(SPACE);
             sBuilder.append(rec.getString("Column5")).append(SPACE);
             
             model.addElement(sBuilder.toString());
            }
          st.close();
         
            } catch (SQLException s)  {
          System.out.println("SQL Error: " + s.toString()  + " "
                  + s.getErrorCode() + " " + s.getSQLState());
      } catch (Exception e) {
          System.out.println("Error: " + e.toString()
          + e.getMessage());
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Question by:Evan Redmond
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3 Comments
 
LVL 9

Accepted Solution

by:
Moussa Mokhtari earned 500 total points
ID: 41820870
@Evan Redmond
move
 jList1.setModel(model); 

Open in new window

after the while loop
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Author Comment

by:Evan Redmond
ID: 41820917
It didn't work, I also changed the appending part of the loop and it still didnt work..... so it was:

   while (rec.next())  {
             sBuilder.setLength(0);
            sBuilder.append(rec.getString("Column1")).append(SPACE)
                     .append(rec.getString("Column2")).append(SPACE)
                     .append(rec.getString("Column3")).append(SPACE)
                     .append(rec.getString("Column4")).append(SPACE)
                     .append(rec.getString("Column5")).append(SPACE);
             
             model.addElement(sBuilder.toString());        
            }
          st.close();
          jList1.setModel(model);
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LVL 9

Expert Comment

by:Moussa Mokhtari
ID: 41824150
Are you sure that your model is populated with your data before you set it to jList1 ?
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