how to show data from database to JTable of Java Swing Controls

Question

I have this problem on how to show data from my database using JTable of Java Swing Controls. I just drag and drop the table from the palette in the JForm.

I have no Idea how to code it.

Answer 1

Use this code :

import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.util.Vector;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class DisplayEmpData extends JFrame implements ActionListener {

    JFrame frame1;
    JLabel l0, l1, l2;
    JComboBox c1;
    JButton b1;
    Connection con;
    ResultSet rs, rs1;
    Statement st, st1;
    PreparedStatement pst;
    String ids;
    static JTable table;
    String[] columnNames = {"User name", "Email", "Password", "Country"};
    String from;

    DisplayEmpData() {

        l0 = new JLabel("Fatching Employee Information");
        l0.setForeground(Color.red);
        l0.setFont(new Font("Serif", Font.BOLD, 20));
        l1 = new JLabel("Select name");
        b1 = new JButton("submit");

        l0.setBounds(100, 50, 350, 40);
        l1.setBounds(75, 110, 75, 20);
        b1.setBounds(150, 150, 150, 20);
        b1.addActionListener(this);

        setTitle("Fetching Student Info From DataBase");
        setLayout(null);
        setVisible(true);
        setSize(500, 500);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        add(l0);
        add(l1);;
        add(b1);
        try {
            Class.forName("com.mysql.jdbc.Driver");  // (1)
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_name", "username", "password");  // (2)
            st = con.createStatement();
            rs = st.executeQuery("select uname from emp");
            Vector v = new Vector();
            while (rs.next()) {
                ids = rs.getString(1);
                v.add(ids);
            }
            c1 = new JComboBox(v);
            c1.setBounds(150, 110, 150, 20);

            add(c1);
            st.close();
            rs.close();
        } catch (Exception e) {
        }
    }

    public void actionPerformed(ActionEvent ae) {
        if (ae.getSource() == b1) {
            showTableData();
        }

    }

    public void showTableData() {

        frame1 = new JFrame("Database Search Result");
        frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame1.setLayout(new BorderLayout());
//TableModel tm = new TableModel();
        DefaultTableModel model = new DefaultTableModel();
        model.setColumnIdentifiers(columnNames);
//DefaultTableModel model = new DefaultTableModel(tm.getData1(), tm.getColumnNames());
//table = new JTable(model);
        table = new JTable();
        table.setModel(model);
        table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
        table.setFillsViewportHeight(true);
        JScrollPane scroll = new JScrollPane(table);
        scroll.setHorizontalScrollBarPolicy(
                JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        scroll.setVerticalScrollBarPolicy(
                JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
        from = (String) c1.getSelectedItem();
//String textvalue = textbox.getText();
        String uname = "";
        String email = "";
        String pass = "";
        String cou = "";

        try {
            pst = con.prepareStatement("select * from emp where UNAME='" + from + "'");
            ResultSet rs = pst.executeQuery();
            int i = 0;
            if (rs.next()) {
                uname = rs.getString("uname");
                email = rs.getString("umail");
                pass = rs.getString("upass");
                cou = rs.getString("ucountry");
                model.addRow(new Object[]{uname, email, pass, cou});
                i++;
            }
            if (i < 1) {
                JOptionPane.showMessageDialog(null, "No Record Found", "Error", JOptionPane.ERROR_MESSAGE);
            }
            if (i == 1) {
                System.out.println(i + " Record Found");
            } else {
                System.out.println(i + " Records Found");
            }
        } catch (Exception ex) {
            JOptionPane.showMessageDialog(null, ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
        }
        frame1.add(scroll);
        frame1.setVisible(true);
        frame1.setSize(400, 300);
    }

    public static void main(String args[]) {
        new DisplayEmpData();
    }
}

EDIT: The above code use mysql as an example. Change the line marked with (1) and (2) if you are not using mysql.

Answer 2

you need to connect your java program to your database using a JDBC. after that you need to extract the data using ResultSet class. you need to understand the basics of JDBC and bey clear about the commands of your database. You also need to know how to work with databases through java. so read the online tutorial of java by oracle(official tutorial).it will not take more than a hour. life will be easier