populating JTable using values from another method

Question

I am using Eclipse & Swing to create this project. I am trying to populate a JTable. I've fetched the values from database in the method Display_UserInfo_in_JTable().

But I do not know how to use this method to populate my JTable. I think the method should have a return type for this, but I do not know how can I do it?

package view;

import controller.*;
import java.awt.EventQueue;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

public class TableView {

    private JFrame frame;
    private JTable table;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    TableView window = new TableView();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    private ArrayList<UserInfo> UserInfoList()
    {
        try
        {
            UserInfo userinfo;
            ArrayList<UserInfo> UserInfoList = new ArrayList<UserInfo>();
            Connection sqlCon = DB_con.getSQLConnection();
            PreparedStatement ps = sqlCon.prepareStatement("select id,name,username,contact,gender from temp");

            ResultSet rs = ps.executeQuery();
            while(rs.next())
            {
                userinfo = new UserInfo(
                                        rs.getInt("id"),
                                        rs.getString("name"),
                                        rs.getString("username"),
                                        rs.getString("contact"),
                                        rs.getString("gender")
                                        );
                UserInfoList.add(userinfo);
            }
            return UserInfoList;
        }
        catch(Exception ex)
        {
            System.out.println(ex.toString());
            return null;
        }       
    }

    public void Display_UserInfo_in_JTable()
    {
        try
        {
            ArrayList<UserInfo> list = UserInfoList();
            DefaultTableModel dtm = new DefaultTableModel();
            Object row[] = new Object[5];

            for(int i = 0 ; i < list.size(); i++)
            {
                row[0] = list.get(i).getId();
                row[1] = list.get(i).getName();
                row[2] = list.get(i).getUsername();
                row[3] = list.get(i).getContact();
                row[4] = list.get(i).getGender();

                dtm.addRow(row);
            }
            table.setModel(dtm);
        }
        catch(Exception ex)
        {
            System.out.println(ex.toString());
        }
    }

    /**
     * Create the application.
     */
    public TableView() {
        initialize();
        Display_UserInfo_in_JTable();

    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 598, 402);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        JPanel panel = new JPanel();
        panel.setBounds(10, 11, 562, 341);
        frame.getContentPane().add(panel);
        panel.setLayout(null);

        table = new JTable();
        //table.setBounds(49, 163, 92, -97);
        JScrollPane jsp = new JScrollPane(table);
        panel.add(table);
    }
}

I've added table.setModel(dtm); in the method Display_UserInfo_in_JTable(), still can not get the result.

Answer 1

There are too many problems with your code :

1. Coding and naming conventions
2. The displayUserInfoInJTable() never gets called (or atleast you haven't posted that code)
3. The table model isn't supposed to be coded this way
4. There are no column identifiers, just the rows
5. You have used an absolute layout (layout set as null) but your bounds are negative -97, this is likely your main issue

For point 5, either use a standard layout or set the bounds accordingly.