Java Application to connect to vdb3 database

Question

Hi Folks,
I have to create a java application to connect to vdb3 oracle databse to support various transactions with menu options as below:
File menu(ALT F)
---Connect (ALT L)
---Exit (ALT E)
Data menu(ALT D)
---Query(ALT Q)
---Add Student(ALT A)
---Delete Student(ALT T)
---Update Student(ALT U)
Option menu(ALT O)
---Color(ATL C)
---Font (ATL N)
There is a STUDENT table with studid, firstname, lastname, major and age.
I have the following code for the GUI. I am getting the following errors. How do I go about from here? Please help.
Student.java:13: cannot find symbol
symbol : class ControlPanel
location: class Student
private ControlPanel controls;
^
Student.java:38: cannot find symbol
symbol: method GridLayout(int,int,int,int)
frame.add(panel, GridLayout(4,2,5,5));
^
Student.java:49: cannot find symbol
symbol : method addWindowListener(<anonymous java.awt.event.WindowAdapter>)
location: class javax.swing.JMenuItem
exititem.addWindowListener(
^
Student.java:69: cannot find symbol
symbol : method JMenuItem(java.lang.String)
location: class Student
JMenuItem queryItem = JMenuItem("Query");
^
Student.java:78: cannot find symbol
symbol : method showMessgaeDialog(<nulltype>,java.awt.Component,java.lang.String,int)
location: class javax.swing.JOptionPane
JOptionPane.showMessgaeDialog(null, add(queryoutput), "QUERY RESULTS", JOptionPane.INFORMATION_MESSAGE);
import javax.swing.*;
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
public class Student extends JFrame
     private JTextArea out;
     private JDesktopPane desktop;
     private JTextArea queryoutput;
     private ControlPanel controls;
     public Student()
          super(" Student Database");
          //container c = getContentPane();
          desktop = new JDesktopPane();
          add(desktop);
          JMenu fileMenu = new JMenu("File");
          fileMenu.setMnemonic('F');
          JMenuItem connectItem = new JMenuItem("Connect");
          connectItem.setMnemonic('L');
          fileMenu.add(connectItem);
          connectItem.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
                    JInternalFrame frame = new JInternalFrame("Login", true, true, true, true );
                    MyPanel panel = new MyPanel();
                    frame.add(panel, GridLayout(4,2,5,5));
                    frame.pack();
                    desktop.add(frame);
                    frame.setVisible(true);
          JMenuItem exititem = new JMenuItem("Exit");
          exititem.setMnemonic('E');
          fileMenu.add(exititem);
          exititem.addWindowListener(
               new WindowAdapter()
                    public void WindowClosing (WindowEvent event)
                         System.exit(0);
          JMenuBar bar = new JMenuBar();
          setJMenuBar(bar);
          bar.add(fileMenu);
          queryoutput = new JTextArea(5,20);
          JMenu dataMenu = new JMenu("Data");
          dataMenu.setMnemonic('D');
          JMenuItem queryItem = JMenuItem("Query");          
          queryItem.setMnemonic('Q');
          dataMenu.add(queryItem);
          dataMenu.addSeparator();
          dataMenu.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
                    JOptionPane.showMessgaeDialog(null, add(queryoutput), "QUERY RESULTS", JOptionPane.INFORMATION_MESSAGE);
          JMenuItem addstud = new JMenuItem("Add Student");
          addstud.setMnemonic('A');
          dataMenu.add(addstud);
          dataMenu.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
          JMenuItem delstud = new JMenuItem("Delete Student");
          addstud.setMnemonic('T');
          dataMenu.add(delstud);
          dataMenu.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
          JMenuItem updatestud = new JMenuItem("Update Student");
          addstud.setMnemonic('U');
          dataMenu.add(updatestud);
          dataMenu.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
          JMenu options = new JMenu("Options");
          options.setMnemonic('O');
          JMenuItem color = new JMenuItem("Color");
          addstud.setMnemonic('C');
          options.add(color);
          options.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
          JMenuItem font = new JMenuItem("Font");
          addstud.setMnemonic('N');
          options.add(font);
          options.addActionListener(
               new ActionListener()
                    public void actionPerformed(ActionEvent event)
class MyPanel extends JPanel
          private JLabel L1;
          private JLabel L2;
          private JLabel L3;
          private JTextField userid;
          private JPasswordField pw;
          private JTextField database;
          private JButton ok;
          private Connection connect;
          private JTextArea output;
          private String url;
     public MyPanel()
          L1 = new JLabel("User Id:");
          add(L1);
          userid = new JTextField(10);
          add(userid);
          L2 = new JLabel("Password:");
          add(L2);
          pw = new JPasswordField(10);
          add(pw);
          L3 = new JLabel("Database Name:");
          add(L3);
          database = new JTextField(10);
          add(database);
          ok = new JButton("OK");
          add(ok);
          ok.addActionListener(     
          new ActionListener()
               public void actionPerformed(ActionEvent event)
               try {
     url = "jdbc:odbc:Student";
     Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" );
     connect = DriverManager.getConnection( url );
     output.append( "Connection successful\n" );
          catch ( ClassNotFoundException cnfex ) {     
     // process ClassNotFoundExceptions here
     cnfex.printStackTrace();     
     output.append( "Connection unsuccessful\n" +
cnfex.toString() );
     catch ( SQLException sqlex ) {
     // process SQLExceptions here
     sqlex.printStackTrace();
     output.append( "Connection unsuccessful\n" +
sqlex.toString() );
     catch ( Exception ex ) {
     // process remaining Exceptions here
     ex.printStackTrace();
     output.append( ex.toString() );
import javax.swing.*;
public class MainWindow
     public static void main( String args[])
          Student student = new Student();
          student.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          student.setSize(500,200);
          student.setVisible( true);
}

Answer 1

Error messages tell you everything you need to know (usually).
Student.java:13: cannot find symbol
symbol : class ControlPanel
location: class Student
private ControlPanel controls;
^
This means that the compiler cannot find the class ControlPanel. Does it exists. Is it in the same directory as your other files. Has it compiled correctly.
Student.java:38: cannot find symbol
symbol: method GridLayout(int,int,int,int)
frame.add(panel, GridLayout(4,2,5,5));
^
This tells you it cannot find the method GridLayout. I presume you meant to have a new in front of it. Besides the layout manager code should have been done prior to this and your code should be
frame.add(panel);Student.java:49: cannot find symbol
symbol : method addWindowListener(<anonymous java.awt.event.WindowAdapter>)
location: class javax.swing.JMenuItem
exititem.addWindowListener(
^
Once again the method addWindowListener cannot be found. JFrame has this method not JMenuItem. Probably need an ActionListener.
Student.java:69: cannot find symbol
symbol : method JMenuItem(java.lang.String)
location: class Student
JMenuItem queryItem = JMenuItem("Query");
^
Once again the compiler thinks you are trying to call a method called JMenuItem. You forgot new.
Student.java:78: cannot find symbol
symbol : method showMessgaeDialog(<nulltype>,java.awt.Component,java.lang.String,int)
location: class javax.swing.JOptionPane
JOptionPane.showMessgaeDialog(null, add(queryoutput), "QUERY RESULTS", JOptionPane.INFORMATION_MESSAGE);
Spelling!