creating a login form with java connected to mysql

Question

I created a java login frame using netbeans and I connected it to MySQL using MySQL Connector/J which the jar file was added to the projects library. I also created a table called login which includes all the login details. The following codes are supposed to permit login but I keep getting errors as if the connection to the database was not established.

package Lightapp;
import java.sql.* ;
import javax.swing.* ;

public class AbbeyLog extends javax.swing.JFrame
{
    Connection conn = null;
    ResultSet rs = null;
    PreparedStatement pst = null;

    /**
     * Creates new form AbbeyLog
     */
    public AbbeyLog()
    {
        initComponents();
    }

    @SuppressWarnings("unchecked")
    private void textuserActionPerformed(java.awt.event.ActionEvent evt)
    {
        // TODO add your handling code here:
        String sql = "select * from login where username = ? and password = ?";
        try
        {
            pst = conn.prepareStatement(sql);
            pst.setString(1, textuser.getText());
            pst.setString(2, textpass.getText());
            rs = pst.executeQuery();
            if (rs.next())
            {
                JOptionPane.showMessageDialog(null, "Username and Password correct");
            }
            else
            {
                JOptionPane.showMessageDialog(null, "invalid username and password");
            }
        }
        catch (Exception e)
        {
            JOptionPane.showMessageDialog(null, e);
        }
    }

    private void textuserMouseClicked(java.awt.event.MouseEvent evt)
    {
        // TODO add your handling code here:
    }


    public static void main(String args[])
    {
        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                new AbbeyLog().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify
    private javax.swing.JButton jButton2;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField textpass;
    private javax.swing.JButton textuser;
    // End of variables declaration
}

Solution

You need to create a jdbc connection at startup:

//load the driver
Class.forName("com.mysql.jdbc.Driver").newInstance();
// create a connection         
conn = DriverManager.getConnection("jdbc:mysql://"+hostName+":"
                + dbPort+"/"+databaseName+"?"+"user="+dbUser+"&password=" + dbPassword);

Comments

[lee]

ive tried it your was but i keep getting thos error Java.sql.sqlexception: no suitable driver found

[lee]

ive tried it your was but i keep getting thos error Java.sql.sqlexception: no suitable driver found

[Stefan]

1. Put it in the constructor or in a method you call when starting up your client. 2. Please check the mysql connector/j (mysql-connector-java-5.1.22-bin.jar) is in your project (subfolder "libraries"). See here for more details: dev.mysql.com/doc/refman/5.1/en/…

[Alucard]

You need to have the jar file corresponding to your drivers. If you have it in the right folder and it still dosen't work you can try with other driver, for example the ones proposed by sourceforge (see my post)