i have problem with classnofounderror

import java.sql.*;
public class Tyagi
{
    public static void main (String args[])throws SQLException
    {
        ResultSet rs;
        try
        {
        Class.forName("oracle.jdbc.driver.OracleDriver");
        Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:8080:oracle", "System", "manager");
        Statement st = conn.createStatement();
        rs=st.executeQuery("Select * from student");
        while(rs.next())
            System.out.println(rs.getString(1));
        st.close();
        conn.close();
        }
        catch(Exception e)
        {
        System.out.println(e);
        }
    }
}