package problem

[tyler jones]

I'm working through a tutorial on Sun's website and it has you create one main class and about 6 or so other classes all in a package called divelog. Although I haven't created my own packages before, I understand the concept. So, I have one class like this...

package divelog;
import javax.swing.*;
import java.awt.*;
public class Welcome extends JPanel
{
}

and then my main class that tries to use this class....

package divelog;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*; 

public class DiveLog 
{
 
  private JTabbedPane tabbedPane;
  private JFrame dlframe; 
  
      public DiveLog()
      {
      
        dlframe = new JFrame("A Java(TM) Technology Dive Log");
        
        dlframe.addWindowListener(new WindowAdapter() 
        {
          public void windowClosing(WindowEvent e)
          {
             System.exit(0);
           }
         }); 
         
         tabbedPane = new JTabbedPane(SwingConstants.LEFT);
         tabbedPane.setBackground(Color.blue);
         tabbedPane.setForeground(Color.white);
         populateTabbedPane();
         
         buildMenu();
         
         dlframe.getContentPane().add(tabbedPane);
         
         dlframe.pack();
         dlframe.setSize(765, 690);
         dlframe.setBackground(Color.white);
         dlframe.setVisible(true);
         } 
         
         private void populateTabbedPane()
           {
           tabbedPane.addTab("Welcome",
                               null,
                               new Welcome(),
                               "Welcome to the Dive Log");
                        
                               
           tabbedPane.addTab("Diver Data",
                               null,
                               new Diver(),
                               "Click here to enter diver data");
                               
           tabbedPane.addTab("Log Dives",
                               null,
                               new Dives(),
                               "Click here to enter dives");
                               
           tabbedPane.addTab("Statistics",
                               null,
                               new Statistics(),
                               "Click here to calculate dive statistics");
                               
           tabbedPane.addTab("Favorite Web Site",
                               null,
                               new WebSite(),
                               "Click here to see a web site");                
           tabbedPane.addTab("Resources",
                               null,
                               new Resources(),
                               "Click here to see a list of resources");         
                     }
         
         private void buildMenu()
         {
           JMenuBar mb = new JMenuBar();
           JMenu menu = new JMenu("File");
           JMenuItem item = new JMenuItem("Exit");
           
           item.addActionListener(new ActionListener()
           {
             public void actionPerformed(ActionEvent e)
             {
                System.exit(0);
              }
              
             });
             
             menu.add(item);
             mb.add(menu);
             dlframe.setJMenuBar(mb);
             }
          
     public static void main(String[] args)
     {
     
      DiveLog dl = new DiveLog();
      }                
 }

When I try to compile the DiveLog.java file, I get an error that divelog.Welcome not found along with all the other classes called in the populateTabbedPane() method of the code when it says new Welcome(), new WebSite(), etc. Can anyone suggest a reason why I can't get this to compile. I've even tried copying all the code for all the classes from the tutorial pages and I still get the same error. Thanks!

[jason adam]

Have you created a folder called divelog that is under whatever path you have set up? That would be my first guess, is it isn't finding the Welcome.class file in the location it should be.
Jason

[tyler jones]

I have set up a folder called divelog right on my c drive. Do I need to update any files to locate it there?

[Jane Griscti]

Hi Tyler,
When you compile start one directory above divelog and use the -d option.
For example, if your directory structure is

c:\javadev\
c:\javadev\divelog        

and both <code>Welcome.java</code> and <code>Divelog.java</code> are in <code>c:\javadev\divelog</code>; make sure you are in <code>c:\javadev</code> and then compile using

javac -d . /divelog/*.java

The -d option tells the compiler to put the .class files in the directory matching the package name; it will search for the <code>divelog</code> directory starting from the current directory. If you compile from within the <code>divelog</code> directory itself it will look for another <code>divelog</code> directory below it.
When you run the program, again, start one level above the <code>divelog</code> directory and enter

java divelog.Divelog

Hope that helps.
------------------
Jane Griscti
Sun Certified Programmer for the Java� 2 Platform

[tyler jones]

Thanks Jane. That worked fine after a bit of tweaking. So, can you explain to me why I couldn't compile from within the package itself? Thanks again.

[Jane Griscti]

Hi Tyler,
The compiler expects to find the directories corresponding to the package names below the current directory.
When you start in <code>divelog</code> the compiler will look for another a subdirectory named <code>divelog</code>. For example, it will expect to see

..\divelog
      \divelog

It always searches from the current directory. If you use a classpath it will begin it's search from the last directory in the classpath. For example, if your classpath was <code>x:\dir\divelog</code> it would still look for another subdirectory <code>divelog</code> starting the search at <code>x:\dir\divelog</code>.
Hope that helps.

[This message has been edited by Jane Griscti (edited October 20, 2001).]