Information

Picture of the issue in question

Code:

/*
    Chapter 11: The MakeDB Class
    Programmer:    Myles Brown
    Date:        November 30, 2012
    Filename:    MakeDB.java
    Purpose:    To build an initial database for the StockTracker application
*/

import java.sql.*;
import java.io.*;
H:> java -classpath H:\Java I\Chapter 11\Programs\JBDC\StockTracker.mdb;
  public class MakeDB
  {
    public static void main(String[] args) throws Exception
    {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

        String url = "jdbc:odbc:StockTracker";

        Connection con = DriverManager.getConnection(url);
        Statement stmt = con.createStatement();

        // The following code deletes each index and table, if they exist.
        // If they do not exist, a message is displayed and execution continues.
        System.out.println("Dropping indexes & tables ...");

        try
        {
            stmt.executeUpdate("DROP INDEX PK_UserStocks ON UserStocks");

        }
        catch (Exception e)
        {
            System.out.println("Could not drop primary key on UserStocks table: "
                              + e.getMessage());
        }

        try
        {
              stmt.executeUpdate("DROP TABLE UserStocks");
        }
        catch (Exception e)
        {
            System.out.println("Could not drop UserStocks table: "
                              + e.getMessage());
        }

        try
        {
              stmt.executeUpdate("DROP TABLE Users");
        }
        catch (Exception e)
        {
            System.out.println("Could not drop Users table: "
                              + e.getMessage());
        }

        try
        {
              stmt.executeUpdate("DROP TABLE Stocks");
        }
        catch (Exception e)
        {
            System.out.println("Could not drop Stocks table: "
                              + e.getMessage());
        }

        ///////// Create the database tables /////////////
        System.out.println("\nCreating tables ............");

        // Create Stocks table with primary key index
        try
        {
            System.out.println("Creating Stocks table with primary key index...");
            stmt.executeUpdate("CREATE TABLE Stocks ("
                              +"symbol TEXT(8) NOT NULL "
                              +"CONSTRAINT PK_Stocks PRIMARY KEY, "
                              +"name TEXT(50)"
                              +")");
        }
        catch (Exception e)
        {
            System.out.println("Exception creating Stocks table: "
                              + e.getMessage());
        }

        // Create Users table with primary key index
        try
        {
            System.out.println("Creating Users table with primary key index...");
            stmt.executeUpdate("CREATE TABLE Users ("
                              +"userID TEXT(20) NOT NULL "
                              +"CONSTRAINT PK_Users PRIMARY KEY, "
                              +"lastName TEXT(30) NOT NULL, "
                              +"firstName TEXT(30) NOT NULL, "
                              +"pswd LONGBINARY, "
                              +"admin BIT"
                              +")");
        }
        catch (Exception e)
        {
            System.out.println("Exception creating Users table: "
                              + e.getMessage());
        }

        // Create UserStocks table with foreign keys to Users and Stocks tables
        try
        {
            System.out.println("Creating UserStocks table ...");
            stmt.executeUpdate("CREATE TABLE UserStocks ("
                              +"userID TEXT(20) "
                               +"CONSTRAINT FK1_UserStocks REFERENCES Users (userID), "
                               +"symbol TEXT(8), "
                               +"CONSTRAINT FK2_UserStocks FOREIGN KEY (symbol) "
                               +"REFERENCES Stocks (symbol))");
        }
        catch (Exception e)
        {
            System.out.println("Exception creating UserStocks table: "
                              + e.getMessage());
        }

        // Create UserStocks table primary key index
        try
        {
            System.out.println("Creating UserStocks table primary key index...");
            stmt.executeUpdate("CREATE UNIQUE INDEX PK_UserStocks "
                              +"ON UserStocks (userID, symbol) "
                              +"WITH PRIMARY DISALLOW NULL");
        }
        catch (Exception e)
        {
            System.out.println("Exception creating UserStocks index: "
                              + e.getMessage());
        }


        // Create one administrative user with password as initial data
        String userID = "admin01";
        String firstName = "Default";
        String lastName = "Admin";
        String initialPswd = "admin01";
        Password pswd = new Password(initialPswd);
        boolean admin = true;

        PreparedStatement pStmt =
                   con.prepareStatement("INSERT INTO Users VALUES (?,?,?,?,?)");
        try
        {
            pStmt.setString(1, userID);
            pStmt.setString(2, lastName);
            pStmt.setString(3, firstName);
            pStmt.setBytes(4, serializeObj(pswd));
            pStmt.setBoolean(5, admin);
            pStmt.executeUpdate();
        }
        catch (Exception e)
        {
            System.out.println("Exception inserting user: "
                              + e.getMessage());
        }

        pStmt.close();

        // Read and display all User data in the database.
        ResultSet rs = stmt.executeQuery("SELECT * FROM Users");

        System.out.println("Database created.\n");
        System.out.println("Displaying data from database...\n");
        System.out.println("Users table contains:");

        Password pswdFromDB;
        byte[] buf = null;

        while(rs.next())
        {
            System.out.println("Logon ID         = "
                              + rs.getString("userID"));
            System.out.println("First name       = "
                              + rs.getString("firstName"));
            System.out.println("Last name        = "+rs.getString("lastName"));
            System.out.println("Administrative   = "+rs.getBoolean("admin"));
            System.out.println("Initial password = "+initialPswd);

        // Do NOT use with JDK 1.2.2 using JDBC-ODBC bridge as
        // SQL NULL data value is not handled correctly.
            buf = rs.getBytes("pswd");
            if (buf != null)
            {
                System.out.println("Password Object  = "
                                  + (pswdFromDB=(Password)deserializeObj(buf)));
                System.out.println("  AutoExpires    = "+ pswdFromDB.getAutoExpires());
                System.out.println("  Expiring now   = "+ pswdFromDB.isExpiring());
                System.out.println("  Remaining uses = "
                                  + pswdFromDB.getRemainingUses()+"\n");
            }
            else
                System.out.println("Password Object  = NULL!");
        }

        rs = stmt.executeQuery("SELECT * FROM Stocks");
        if(!rs.next())
            System.out.println("Stocks table contains no records.");
        else
            System.out.println("Stocks table still contains records!");

        rs = stmt.executeQuery("SELECT * FROM UserStocks");
        if(!rs.next())
            System.out.println("UserStocks table contains no records.");
        else
            System.out.println("UserStocks table still contains records!");

        stmt.close(); // closing Statement also closes ResultSet

    } // end of main()

    // Method to write object to byte array and then insert into prepared statement
    public static byte[] serializeObj(Object obj)
                              throws IOException
    {
        ByteArrayOutputStream baOStream = new ByteArrayOutputStream();
        ObjectOutputStream objOStream = new ObjectOutputStream(baOStream);

        objOStream.writeObject(obj); // object must be Serializable
        objOStream.flush();
        objOStream.close();
        return baOStream.toByteArray(); // returns stream as byte array
    }

    // Method to read bytes from result set into a byte array and then
    // create an input stream and read the data into an object
    public static Object deserializeObj(byte[] buf)
                            throws IOException, ClassNotFoundException
    {
        Object obj = null;

        if (buf != null)
        {
          ObjectInputStream objIStream =
            new ObjectInputStream(new ByteArrayInputStream(buf));

          obj = objIStream.readObject(); // throws IOException, ClassNotFoundException
        }
        return obj;
    }
  } // end of class

What I think is mucking it up part 1

Code:

import javax.swing.*;
import javax.swing.border.TitledBorder;
import static javax.swing.JOptionPane.*;            // updated for v5.0
import java.awt.*;
import java.awt.event.*;
import static java.awt.BorderLayout.*;                // updated for v5.0
import java.util.*;
import java.io.*;
import java.sql.*;

public class STLogon extends JFrame implements ActionListener, Activator
{
    StockTrackerDB db;
    User user = null;
    String userID;
    String password;

    JTextField userIDField;
    JPasswordField passwordField;
    JButton jbtLogon;

    public STLogon()
    {
        super("Stock Tracker"); // call super (JFrame) constructor

        int width = 300;
        int height = 100;

        try{
            db = new StockTrackerDB();
        }
        catch(ClassNotFoundException ex){
                JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "Class not found exception creating database object",
                ERROR_MESSAGE);                    // updated for v5.0
                   System.exit(0);
        }
        catch(SQLException ex){
                JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "SQL exception creating database object",
                ERROR_MESSAGE);                    // updated for v5.0
                   System.exit(0);
        }

        // define GUI components
        JLabel label1 = new JLabel("User ID: ");
        userIDField = new JTextField(20);

        JLabel label2 = new JLabel("Password:   ");
        passwordField = new JPasswordField(20);
        passwordField.setEchoChar('*');

        jbtLogon = new JButton("Log on");

        // set up GUI
        JPanel userPanel= new JPanel(new BorderLayout());
        userPanel.add(label1,CENTER);
        userPanel.add(userIDField,EAST);

        JPanel pswdPanel= new JPanel(new BorderLayout());
        pswdPanel.add(label2,CENTER);
        pswdPanel.add(passwordField,EAST);

        JPanel buttonPanel= new JPanel(new FlowLayout());
        buttonPanel.add(jbtLogon);

        JPanel contentPanel= new JPanel(new BorderLayout());
        contentPanel.add(userPanel, NORTH);
        contentPanel.add(pswdPanel, CENTER);
        contentPanel.add(buttonPanel, SOUTH);
        contentPanel.setBorder(new TitledBorder("Log on"));

        setContentPane(contentPanel);

        // add listeners
        jbtLogon.addActionListener(this);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e)
                        {
                            try {db.close();
                            }
                            catch(Exception ex)
                            {}
                            System.exit(0);
                        }
            });

        // Enable Enter key for each JButton
        InputMap map;
        map = jbtLogon.getInputMap();
        if (map != null){
            map.put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER,0,false), "pressed");
            map.put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER,0,true), "released");
        }

        pack();
        if( width < getWidth())                // prevent setting width too small
           width = getWidth();
        if(height < getHeight())            // prevent setting height too small
            height = getHeight();
        centerOnScreen(width, height);
    }

      public void centerOnScreen(int width, int height)
      {
        int top, left, x, y;

        // Get the screen dimension
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

        // Determine the location for the top left corner of the frame
        x = (screenSize.width - width)/2;
        y = (screenSize.height - height)/2;
        left = (x < 0) ? 0 : x;
        top = (y < 0) ? 0 : y;

        // Set the frame to the specified location & size
      this.setBounds(left, top, width, height);
      }

    private boolean validUser(String userID,String password)
                throws PasswordException,SQLException,IOException,ClassNotFoundException
    {
        boolean userOK = false;
        user = db.getUser(userID); // get user object from DB for this ID
        if(user != null)
        {
            user.validate(password); // throws PasswordException
            userOK = true;
            if(user.pswdAutoExpires())    // if tracking uses
                db.updUser(user);        // update DB for this use
        }

        return userOK;
    }

    private void doStockActivity()throws PasswordException,SQLException,
                                         IOException,ClassNotFoundException
    {
        StockTracker f = new StockTracker(user,this,db);
        f.pack();
        this.setVisible(false);
        f.setVisible(true);
    }

    public void activate()
    {
        this.setVisible(true);
        userIDField.setText("");
        userIDField.requestFocus();
        user = null;
    }

    public void actionPerformed(ActionEvent e)
    {
        try
        {
            userID = userIDField.getText();
            if(userID.equals(""))
            {
                   JOptionPane.showMessageDialog(this,
                    "Please enter a valid user ID.",
                    "Missing User ID.",
                    ERROR_MESSAGE);                    // updated for v5.0
                userIDField.requestFocus();
            }
            else
            {
                password = new String(passwordField.getPassword());
                if(password.equals(""))
                {
                       JOptionPane.showMessageDialog(this,
                        "Please enter a valid password.",
                        "Missing Password.",
                        ERROR_MESSAGE);                    // updated for v5.0
                    passwordField.requestFocus();
                }
                else
                {
                    try
                    {
                        // See if userID exists and validate password
                        if(validUser(userID,password))
                        {
                            if(user.pswdIsExpiring())
                                    JOptionPane.showMessageDialog(this,
                                                user.getUserID()+" logon successful; "
                                           +user.getPswdUses()+" use(s) remaining.");
                            if(e.getSource() == jbtLogon)
                                      doStockActivity();
                        }
                        else
                            JOptionPane.showMessageDialog(this, "Invalid user.");
                    }
                    catch (PasswordExpiredException ex)
                    {
                        JPasswordField pf1 = new JPasswordField();
                        JPasswordField pf2 = new JPasswordField();
                        Object[] message1 = new Object[]
                                {"Password has expired. Please enter a new password.", pf1};
                        Object[] options = new String[] {"OK", "Cancel"};
                        JOptionPane op1 = new JOptionPane(message1,
                                              WARNING_MESSAGE,                // updated for v5.0
                                              OK_CANCEL_OPTION, null, options);    // updated for v5.0
                        JDialog dialog1 = op1.createDialog(null, "Change Password");
                        dialog1.setVisible(true);    // updated for v5.0

                        if(op1.getValue() != null && options[0].equals(op1.getValue()))
                        {
                            String pswd1 = new String(pf1.getPassword());
                            if(pswd1 != null)
                            {
                                Object[] message2 = new Object[]
                                                {"Please verify new password.", pf2};
                                JOptionPane op2 = new JOptionPane(message2,
                                                      WARNING_MESSAGE,  // updated for v5.0
                                                      OK_CANCEL_OPTION,    // updated for v5.0
                                                            null, options);
                                JDialog dialog2 = op2.createDialog(null, "Verify Password");
                                dialog2.setVisible(true);    // updated for v5.0
                                if(op2.getValue() != null && options[0].equals(op2.getValue()))
                                {
                                    String pswd2 = new String(pf2.getPassword());
                                    if(pswd2 != null)
                                    {
                                        if(pswd1.equals(pswd2))
                                        {
                                            user.changePassword(password, pswd1);
                                            db.updUser(user);
                                            doStockActivity();
                                        }
                                        else
                                            JOptionPane.showMessageDialog(this,
                                            "Both passwords are not identical.",
                                            "Password not changed",
                                            ERROR_MESSAGE);                    // updated for v5.0
                                    }
                                }
                            }
                        }
                    }
                }
            }
            userIDField.setText("");
            passwordField.setText("");
            userIDField.requestFocus();
        }// end of try
        catch (PasswordUsedException ex)
        {
            JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "Password Previously Used. Try again.",
                ERROR_MESSAGE);                    // updated for v5.0
        }
        catch (PasswordSizeException ex)
        {
            JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "Invalid password size. Try again.",
                ERROR_MESSAGE);                    // updated for v5.0
        }
        catch (PasswordInvalidFormatException ex)
        {
            if(ex.getCount() > 2) // allows only 3 tries, then exits program
                System.exit(0);
            else
                JOptionPane.showMessageDialog(this,ex.getMessage()+", count:"+ex.getCount(),
                                                   "Invalid password format. Try again.",
                                                   ERROR_MESSAGE);    // updated for v5.0
        }
        catch (PasswordInvalidException ex)
        {
            if(ex.getCount() > 2) // allows only 3 tries, then exits program
                System.exit(0);
            else
                JOptionPane.showMessageDialog(this,ex.getMessage()+", count:"+ex.getCount(),
                                                   "Invalid password. Try again.",
                                                   ERROR_MESSAGE);    // updated for v5.0
        }
        catch (PasswordException ex)
        {
            JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "PasswordException.",
                ERROR_MESSAGE);                    // updated for v5.0
        }

        catch (IOException ex)
        {
            JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "IOException.",
                ERROR_MESSAGE);                    // updated for v5.0
        }
        catch (SQLException ex)
        {
            JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "SQLException.",
                ERROR_MESSAGE);                    // updated for v5.0
        }
        catch (ClassNotFoundException ex)
        {
            JOptionPane.showMessageDialog(this,
                ex.getMessage(),
                "ClassNotFoundException.",
                ERROR_MESSAGE);                    // updated for v5.0
        }
    }

    public static void main(String[] argv)
    {
        final STLogon f = new STLogon();
        f.setVisible(true);
    }
}

What I think is mucking it up part 2

Polantaris Wrote:You may be better off using Eclipse or a similar IDE (NetBeans is another one. I personally prefer Eclipse). Eclipse is 100x better, in my opinion, especially when it comes to file management.

I think the issue is simply that everything isn't properly managed in TextPad. Eclipse should help with that.

That's just my opinion, I could be completely off with it being the issue, however I think getting off of TextPad now will help you in the future. I've made this recommendation to many people in my own classes, and most of them have thanked me afterwards.

About the bonus issue: Honestly, programming is a major example of "learn by doing." You can look at books and copy book code all day, but it doesn't help if you don't do anything yourself. Even these examples that you have from books, manipulate them. Do things to them that are not part of the project. Anything you can think of, even if it sounds simple in your head.

Then, after you've done a decent amount of manipulating other people's codes, try making your own projects. Think of something random, it doesn't need to be something super cool or something super sophisticated. Just make a program that does something, takes user input, uses files, etc. Then, when you get it all working, think about how you can make it more efficient code. For example, if you have the same code multiple times, wouldn't it be better to separate this code into a single method and just call that method multiple times instead of copying the same code over and over? Always think about error checking. All that kind of stuff.

One of the great things about Java is that it has a TON of two things: Information and Libraries. Java Commenting has the ability to work in comment resource pages in them (/** initiates this). Anyone who makes anything important that they release to other people make use of this. Why is this helpful? Well... There's a library for just about everything, the hard work is often done for you by someone else already. Make use of that. It's a powerful resource in Java. If you don't understand what something is doing or does, you open the comment resource page, and it's all described (hopefully in a helpful way).

Hope this helps.

Piggy 2.0 Wrote:A friend mentioned Eclipse to me as well last year. He gave me the files for it, but I lost them due to last-minute-shenanigans. I only work in TextPad because thats what I use up at my class, and I dunno if Eclipse stores or converts the files differently since I have to send them to my teacher when I'm done with all the projects. I'll definitely start using it at home, however.

Other than that, holy hot damn is that helpful.