Problem with Linked List

i have make a database with linked list for a School student counselor.
The to be store is
student name, ID, Counseling Date, Progress
In there there will be record for a student and the Date and progress has to be stored for 4-weeks as the counseling is on weekly basis. These data items will be multivalued(what u say in Databases) how i can store this repetitive data in linked list for one student.

By capsulating the data in objects and adding the objects to a linked list.

Similar Messages

Help with linked lists and searching

Hi guys I'm very new to java. I'm having a problem with linked lists. the program's driver needs to create game objects, store them, be able to search the linked list etc. etc. I've read the API but I am really having trouble understanding it.
First problem is that when I make a new game object through the menu when running the program, and then print the entire schedule all the objects print out the same as the latest game object created
Second problem is searching it. I just really have no idea.
Here is the driver:
import java.util.*;
public class teamSchedule
     public static void main (String[]args)
          //variables
          boolean start;
          game game1;
          int selector;
          Scanner scanner1;
          String date = new String();
          String venue = new String();
          String time = new String();
          String dateSearch = new String();
          double price;
          String opponent = new String();
          int addindex;
          List teamSchedLL = new LinkedList();
          String dateIndex = new String();
          String removeYN = new String();
          String venueIndex = new String();
          String opponentIndex = new String();
          start = true; //start makes the menu run in a while loop.
          while (start == true)
               System.out.println("Welcome to the Team Scheduling Program.");
               System.out.println("To add a game to the schedule enter 1");
               System.out.println("To search for a game by date enter 2");
               System.out.println("To search for a game by venue enter 3");
               System.out.println("To search for a game by opponent enter 4");
               System.out.println("To display all tour information enter 5");
               System.out.println("");
               System.out.println("To remove a game from the schedule enter search for the game, then"
                                        + " remove it.");
               System.out.println("");
               System.out.println("Enter choice now:");
               scanner1 = new Scanner (System.in);
               selector = scanner1.nextInt();
               System.out.println("");
               if (selector == 1)
                    //add a game
                    scanner1.nextLine();
                    System.out.println("Adding a game...");
                    System.out.println("Enter game date:");
                    date = scanner1.nextLine();
                    System.out.println("Enter game venue:");
                    venue = scanner1.nextLine();
                    System.out.println("Enter game time:");
                    time = scanner1.nextLine();
                    System.out.println("Enter ticket price:");
                    price = scanner1.nextDouble();
                    scanner1.nextLine();
                    System.out.println("Enter opponent:");
                    opponent = scanner1.nextLine();
                    game1 = new game(date, venue, time, price, opponent);
                    teamSchedLL.add(game1);
                    System.out.println(teamSchedLL);
                    System.out.println("Game created, returning to main menu. \n");
                    start = true;
               else if (selector == 2)
                    //search using date
                    scanner1.nextLine();
                    System.out.println("Enter the date to search for in the format that it was entered:");
                    dateIndex = scanner1.nextLine();
                    if (teamSchedLL.indexOf(dateIndex) == -1)
                         System.out.println("No matching date found. Returning to main menu.");
                         start = true;
                    else
                         //give user option to remove game if they wish.
                         System.out.println(teamSchedLL.get(teamSchedLL.indexOf(dateIndex)));
                         System.out.println("Would you like to remove this game? Y/N");
                         removeYN = scanner1.nextLine();
                         if (removeYN == "Y" || removeYN == "y")
                              teamSchedLL.remove(teamSchedLL.indexOf(dateIndex));
                              System.out.println("Scheduled game removed.");
                    System.out.println("\n Returning to main menu. \n");
                    start = true;
               else if (selector == 3)
                    //search using venue name
                    scanner1.nextLine();
                    System.out.println("Enter the venue to search for in the format that it was entered:");
                    venueIndex = scanner1.nextLine();
                    if (teamSchedLL.indexOf(venueIndex) == -1)
                         System.out.println("No matching venue found. Returning to main menu.");
                         start = true;
                    else
                         //give user option to remove game
                         System.out.println(teamSchedLL.get(teamSchedLL.indexOf(venueIndex)));
                         System.out.println("Would you like to remove this game? Y/N");
                         removeYN = scanner1.nextLine();
                         if (removeYN == "Y" || removeYN == "y")
                              teamSchedLL.remove(teamSchedLL.indexOf(venueIndex));
                              System.out.println("Scheduled game removed.");
                    System.out.println("\n Returning to main menu. \n");
                    start = true;
               else if (selector == 4)
                    //search using opponent name
                    scanner1.nextLine();
                    System.out.println("Enter the opponent to search for in the format that it was entered:");
                    opponentIndex = scanner1.nextLine();
                    if (teamSchedLL.indexOf(opponentIndex) == -1)
                         System.out.println("No matching opponent found. Returning to main menu.");
                         start = true;
                    else
                         //give user option to remove game
                         System.out.println(teamSchedLL.get(teamSchedLL.indexOf(opponentIndex)));
                         System.out.println("Would you like to remove this game? Y/N");
                         removeYN = scanner1.nextLine();
                         if (removeYN == "Y" || removeYN == "y")
                              teamSchedLL.remove(teamSchedLL.indexOf(opponentIndex));
                              System.out.println("Scheduled game removed.");
                    System.out.println("\n Returning to main menu. \n");
                    start = true;
               else if (selector == 5)
                    //display tour info
                    System.out.println("Tour Schedule:");
                    System.out.println(teamSchedLL + "\n");
               else
                    System.out.println("Incorrect choice entered. Returning to menu");
                    System.out.println("");
                    System.out.println("");
                    System.out.println("");
and here is the game class:
public class game
     private static String gameDate;
     private static String gameVenue;
     private static String gameTime;
     private static double gamePrice;
     private static String gameOpponent;
     public static String gameString;
     //set local variables equal to parameters
     public game(String date, String venue, String time, double price, String opponent)
          gameDate = date;
          gameVenue = venue;
          gameTime = time;
          gamePrice = price;
          gameOpponent = opponent;
     //prints out info about the particular game
     public String toString()
          gameString = "\n --------------------------------------------------------";
          gameString += "\n Date: " + gameDate + " | ";
          gameString += "Venue: " + gameVenue + " | ";
          gameString += "Time: " + gameTime + " | ";
          gameString += "Price: " + gamePrice + " | ";
          gameString += "Opponent: " + gameOpponent + "\n";
          gameString += " --------------------------------------------------------";
          return gameString;
}I'm sure the formatting/style and stuff is horrible but if I could just get it to work that would be amazing. Thanks in advance.
Message was edited by:
wdewind

I don't understand your first problem.
Your second problem:
for (Iterator it=teamSchedLL.iterator(); it.hasNext(); ) {
game game = (game)it.next();
// do the comparation here, if this is the game want to be searched, then break;
}

Getting null returned when working with Linked Lists

Ok, i'm having the same problem with a couple of methods that deal with linked lists, and i was hoping someone could lend me a hand. First off, the specifications for one of the methods:
An iterative procedure smallElements
PARAMETERS: a ListItem reference, ls
an integer n
RETURN VALUE: a new list identical to the given list, except
that it contains no occurrences of numbers greater than n.
for example, given input list ( 3 2 6 3 4 ) and 3,
the return value would be the list ( 3 2 3 )
And here is my code:
ListItem smallElements(ListItem ls, int n){
ListItem small = null;
ListItem result = small;
if(ls == null)
return null;
else{
while(ls!=null){
     if(ls.number <=n){
     result = new ListItem(ls.number, null );
     result = result.next;
     ls = ls.next;
return small;
Like the topic says, i keep getting null returned as a value. I have tried setting small= new ListItem(ls.number, null), and that actually returns the correct list, except that the first number is repeated twice. I would greatly appreciate any assistance.

I am not sure I understand your code. What exactly are those ListItems? It seems to me that you are dealing with single List elements, while the specification says that you are supposed to return a List.
But the main error is that you have two ListItem objects there, which seems to fill the same purpose - only that you use one, and return the other. 'small', which is the one you return, never get set to anything else than null.
I think you should do something like this: make a new, empty list to return
for element in parameterlist
    if number is smaller than n
        add this element to returnlist
return returnlist

Strange problem with linking to external vob-file

I have a strange problem with linking to external vob-file. I
have created a link using BudApi:
on mouseup
set OK = baOpenFile ( the pathname &
"Files\General\Video\VTS_01_1.VOB", "normal")
end
This code opens mpg-videos correctly, but nothing happens
when I try to open vob-files with the same code. The strangest
thing is that when I change the default program for vob-files to
WinDVD this code works and the file opens, but when I change the
default program to Nero Showtime this code doesn't do anything
(when I open the file 'manually' from the folder, it opens
correctly on Nero Showtime). My client uses Nero Showtime, so I
really would appreciate any help on this one.

temes wrote:
>
quote:
Originally posted by:
Newsgroup User
>> When using Nero Showtime as a default program, the
error code is 31,
>> "There is no application associated with the given
filename".
>
> Which suggests that something has gone wrong with file
associations.
> If
> you double-click one of these files in an Explorer
window does it fire
> up Showtime and open the file?
>
>
> Yes, the file opens correctly in Nero Showtime when
double-clicking
> it in an Explorer. I tried the file associations and
created a
> html-page with a link to the vob-file, and the html-link
opens the
> vob-file correcly with Nero Showtime. My client reported
this
> problem, so it's not just my computer which is having
this problem.
If you open a command prompt, do you get an association
listed like this
example for .txt files:
C:\>assoc .txt
.txt=txtfile
C:\>ftype txtfile
txtfile="D:\Program Files\JGsoft\EditPadLite\EditPadLite.exe"
"%1"
Andrew

Problem with links on email templates

Problem with links on email templates
Hi,
We have been having issues with links on our email templates. Some of the links point to the following URL:
http://server'sname/thirdparty/FCKeditor/editor/fckeditor.html?InstanceName=emailTemplatesDTO.htmlBody&Toolbar=NewscaleFCKEditorToolBar#URL
Sometimes we get “Unknown internal error” on the web page.
Can anyone help or advise on how to resolve this issue?
Many thanks,
Wesley.

Hi Wesley,
This is rather late, but we've seen the same thing frequently (and I believe can replicate it). It's caused when you a creating a new email by copying the content of an existing one with a name space in it.
Upon copying, the link gets scrambled. The approach we use is to copy the email in to a new template, then strip out all of the URL links and add them back in.
Thanks!
Ant

Problem with links for external user

Hi,
We´re using SAP NetWeaver Portal 2004s SPS 10 and we have a problem with links within notification-mails:
The link to the document (e.g. within a subscription mail) consists of "http:///...". Only user using the portal within our network can open this links. All external user can´t open this links. How can I change the URL so that our external user can open the links, too?
Thanks for help,
Sven Keller

We already have another URL for external usage. My problem is how to define that created links to documents and folder are automatically using the external URL.
If somebody receives an email (e.g. subscription) the URL to the folder is:
http://<portalserver>:51000/irj/go/km/navigation/documents/Public Documents/Documentation
But it should be:
https://<externalportal>/irj/go/km/navigation/documents/Public Documents/Documentation
Message was edited by:
Sven Keller

Indesign CS6 on MACs with OS 10.8 are having problems with links

Hi
Indesign CS6 on MACs with 10.8 are having problems with links. All links to other files have to be updated when opening a file although definitely nothing has changed to the linked files.
We can rule out our company's networking and the system hosting the files (HELIOS software on RedHat Linux VM). This happens with newly created Indesign files and with old ones. E.g. we create a file on Tuesday, save it and open it again on the exact same MAC on Wednesday and all links to other fiels (.indd, .png, .bmp, etc. nothing uncommon) have to be updated as they all show the yellow triangle + black exclamation mark symbol next to them. Has anybody else experienced this, What can we do? We have tried absolutley everything and updated all software from MAC OS to CS6 itself but nothing seems to help on the long run.
Any further information required?
M. Miller

Thanks for your quick reply.
We actually noticed that there also seems to be something wrong with the timestamps:
If we open the infos via the MAC finder to a file (.psd e.g.) which is linked in one of our indesign files, it states a certain date of creation.
If we then switch to the Indesign file we just opened in which we had to update all links and open the infos to exactly the same file we looked at in the finder, a different date of creation is stated. So there also seems to be a mistake here (hope it's clear what I mean).
We are ruling out our network as the error cannot be "re-enacted". We have created numerous test files in Indesign (simple white page containing one link to a .psd file which is also used in one of the supposedly defective files) and have opened them on various MACs with various OS versions over the past days/weeks but unfortunately the files open without any notifications or errors.
Just as a background: a few months ago, the problem seemed to occur between MACs with differing OS, 10.6 - 10.8 at first. A file which was created on a 10.6 MAC could not be opened without updating all links on a 10.8 MAC. That is why we updated everything to 10.8. The error did not occur for about 2-3 weeks but then reoccured again.?
Have you heard anything similar?

Having problem with reading list in safari

i am having problem with reading list in safari some time it work sometimes gets hang....

Might be a cache issue ...
Open a Finder window. From the Finder menu bar click Go > Go to Folder
Type or copy paste the following:
~/Library/Caches/com.apple.Safari/Cache.db
Click Go then move the Cache.db file to the Trash.
Quit and relaunch Safari to test.

I continue to have problems with links in email, they don't Work.

I continue to have problems with links in email, they don't work. When I called apple support she said to hard boot by holding off and home keys and restart. However this is only since the new release of the operating system, it happens ever day and it's getting OLD.. Any solutions?

Yes, almost daily since the iOS update. Is there a permanent solution. And does the hard reboot hurt the iPad?

How to Implement a Chained Hash Table with Linked Lists

I'm making a migration from C/C++ to Java, and my task is to implement a Chained Hash Table with a Linked List. My problem is to put the strings(in this case names) hashed by the table using de Division Metod (H(k)= k mod N) in to a Linked list that is handling the colisions. My table has an interface implemented(public boolean insert(), public boolean findItem(), public void remove()). Any Help is needed. Thanks for everyone in advance.

OK. you have your hash table. What you want it to do is keep key/value pairs in linked lists, so that when there is a collision, you add the key/value pair to the linked list rather than searching for free space on the table.
This means that whenever you add an item, you hash it out, check to see if there is already a linked list and if not, create one and put it in that slot. Then in either case you add the key/value pair to the linked list if the key is not already on the linked list. If it is there you have to decide whether your requirements are to give an error or allow duplicate keys or just keep or modify one or the other (old/new).
When you are searching for a key, you hash it out once again and check to see if there is a linked list at that slot. If there is one, look for the key and if it's there, return it and if not, or if there was no linked list at that slot, return an error.
You aren't clear on whether you can simply use the provided linked-list implementations in the Java Collections or whether you have to cobble the linked list yourself. In any case, it's up to you.
Is this what you're asking?
Doug

Problem with ALV list

Hi friends,
              I have created one program with alv list, but i am unable to add one header and footer, also i have to add one logo to the program. Plese some one tell me a easy procedure to add a header, footer and also a logo. If you can show me one with example that would be very helpful.
This is my program, plz add the necessary parts.
*& Report Y_BOM2_ALV
REPORT y_bom2_alv LINE-SIZE 350 LINE-COUNT 350.
*& Include YINCLUDE1
TABLES : mast, stko, stpo.
TYPE-POOLS : slis.
DATA : BEGIN OF iall OCCURS 10,
matnr LIKE mast-matnr,
werks LIKE mast-werks,
stlan LIKE mast-stlan,
stlal LIKE mast-stlal,
stlst LIKE stko-stlst,
posnr LIKE stpo-posnr,
idnrk LIKE stpo-idnrk,
menge LIKE stpo-menge,
meins LIKE stpo-meins,
ausch LIKE stpo-ausch,
lgort LIKE stpo-lgort,
END OF iall.
DATA : i_repid LIKE sy-repid,
i_lines LIKE sy-tabix.
DATA : int_fcat TYPE slis_t_fieldcat_alv.
SELECTION-SCREEN BEGIN OF BLOCK a1 WITH FRAME TITLE title1.
PARAMETER : p_werks LIKE mast-werks.
SELECT-OPTIONS : s_matnr FOR mast-matnr.
SELECTION-SCREEN END OF BLOCK a1.
INITIALIZATION.
title1(50) = ' Bill Of Material Input Screen '.
*& Include YINCLUDE2
START-OF-SELECTION.
SELECT mastmatnr mastwerks maststlan maststlal stko~stlst
stpoposnr stpoidnrk stpomenge stpomeins stpo~ausch
stpo~lgort INTO TABLE iall FROM stpo INNER JOIN stko ON
stpostlnr = stkostlnr INNER JOIN mast ON
stpostlnr = maststlnr WHERE mast~werks EQ
p_werks AND mast~matnr IN s_matnr.
IF sy-subrc <> 0 OR p_werks EQ ' ' OR s_matnr EQ ' '.
CALL FUNCTION 'POPUP_TO_DISPLAY_TEXT'
EXPORTING
titel = 'ERROR MESSAGE ( INPUT ERROR / WRONG INPUT ) '
textline1 = ' PLANT / MATERIAL Invalid or Empty '
textline2 = ' Plese enter plant no / material no again '
start_column = 20
start_row = 5.
EXIT.
ENDIF.
CLEAR i_lines.
DESCRIBE TABLE iall LINES i_lines.
IF i_lines LT 1.
WRITE: /
'No materials found.'.
EXIT.
ENDIF.
END-OF-SELECTION.
i_repid = sy-repid.
*& Include YINCLUDE3
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'
EXPORTING
i_program_name = i_repid
i_internal_tabname = 'IALL'
i_inclname = i_repid
CHANGING
ct_fieldcat = int_fcat
EXCEPTIONS
inconsistent_interface = 1
program_error = 2
OTHERS = 3.
IF sy-subrc <> 0.
WRITE: /
'Returncode',
sy-subrc,
'from FUNCTION REUSE_ALV_FIELDCATALOG_MERGE'.
ENDIF.
CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
EXPORTING
i_callback_program = i_repid
it_fieldcat = int_fcat
i_save = 'A'
TABLES
t_outtab = iall
EXCEPTIONS
program_error = 1
OTHERS = 2.
IF sy-subrc <> 0.
WRITE: /
'Returncode',
sy-subrc,
'from FUNCTION REUSE_ALV_LIST_DISPLAY'.
ENDIF.

Hi Tapodipta,
See below example and modify ur code according to ur requirement..
REPORT ZTEST_ALV_CHECK        .
TYPE-POOLS: SLIS.
DATA: X_FIELDCAT TYPE SLIS_FIELDCAT_ALV,
      IT_FIELDCAT TYPE SLIS_T_FIELDCAT_ALV,
      L_LAYOUT type slis_layout_alv,
      x_events type slis_alv_event,
      it_events type SLIS_T_EVENT.
DATA: BEGIN OF ITAB OCCURS 0,
      VBELN LIKE VBAK-VBELN,
      POSNR LIKE VBAP-POSNR,
     END OF ITAB.
SELECT VBELN
       POSNR
       FROM VBAP
       UP TO 20 ROWS
       INTO TABLE ITAB.
X_FIELDCAT-FIELDNAME = 'VBELN'.
X_FIELDCAT-SELTEXT_L = 'VBELN'.
X_FIELDCAT-TABNAME = 'ITAB'.
X_FIELDCAT-COL_POS = 1.
APPEND X_FIELDCAT TO IT_FIELDCAT.
CLEAR X_FIELDCAT.
X_FIELDCAT-FIELDNAME = 'POSNR'.
X_FIELDCAT-SELTEXT_L = 'POSNR'.
X_FIELDCAT-TABNAME = 'ITAB'.
X_FIELDCAT-COL_POS = 2.
APPEND X_FIELDCAT TO IT_FIELDCAT.
CLEAR X_FIELDCAT.
x_events-NAME = SLIS_EV_END_OF_PAGE.
x_events-FORM = 'END_OF_PAGE'.
APPEND x_events TO iT_EVENTS.
CLEAR x_events .
x_events-NAME = SLIS_EV_TOP_OF_PAGE.
x_events-FORM = 'TOP_OF_PAGE'.
APPEND x_events TO iT_EVENTS.
CLEAR x_events .
x_events-NAME = slis_ev_end_of_list.
x_events-FORM = 'END_OF_LIST'.
APPEND x_events TO iT_EVENTS.
CLEAR x_events .
CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
EXPORTING
    I_CALLBACK_PROGRAM       = SY-REPID
    IS_LAYOUT                = L_LAYOUT
    IT_FIELDCAT              = IT_FIELDCAT
    it_events                = it_events
TABLES
    T_OUTTAB                 = ITAB
EXCEPTIONS
    PROGRAM_ERROR            = 1
    OTHERS                   = 2.
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
          WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
FORM TOP_OF_PAGE.
* BREAK-POINT.
WRITE: / 'TOP_OF_PAGE'.
ENDFORM.
FORM END_OF_LIST.
* BREAK-POINT.
"here you can use this for footer
WRITE: / 'FOR FOOTER'.
ENDFORM.
FORM END_OF_PAGE.
* BREAK-POINT.
WRITE: / 'END_OF_PAGE'.
ENDFORM.
Go through the link as well..
Re: ALV Footer
Hope it will solve ur problem..
<b>Reward points if useful..</b>
Thanks & Regards
ilesh 24x7

Need help with linked lists.

I have a school assignment to make a linked list with a linked list.
The first basic is to make a list of people, and link them together in a linked list. So far, so good.
The problem comes when I'm going to make linked lists in each of these objects that include the relationships between the people in it.
So If I have 10 peolpe in a list, person 1 might know person 3, 4 and 8. They will all know person 1 back of course. My problem is that it isn't just one group of friends, person 3 might not know person 4 and 8, but maybe he knows person 10. So all need "their own" list.
Therefor I can't see how I'm supposed to use linked lists for them, as I can't just link them togeter with e.g. "Person nextFriend;" The text says specifically to use linked lists. Well, I'm stuck.
Edited by: Skruf on Jan 27, 2009 3:22 PM

Skruf wrote:
I know it doesn't matter what the objects represent, I just needed a way to explain.
But a linked list is basically just a redirect to the next in the list, right?No, a linked list is a particular implementation of a list.
Then I can't see how it's possible to make individual friend lists.No clue what problem you're having.
People with links
null - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - nullThat means nothing.
I can't see how that can be used to make independent links. Do they mean that I'm support to stort it in arrays or something then?
The person list, is (as you can see in my "illustration") only a "next" and "previous" person, so I can't use that way to link the friends together. nextFriend and lastFriend obviously doesn't work.
That's my problemLike I said: A Person object contains a linked list. In that linked list you put references to that Person's friends.

Having trouble with Linked Lists

I'm making a JApplet with buttons from a Linked List, and the buttons should be unique but they're all returning the same icon and string. Also my refreshImages method and deleteStudents method aren't working except for the very last button. This seems like it's just because of how Linked Lists operate, but I can't wrap my head around it.
public class FacebookApplet extends JApplet implements ActionListener{
     private Scanner input;
     protected RefSortedList studentsList;
     protected RefUnsortedList buttonList;
     Student studentVar;
     private JButton b, refreshButton, deleteButton;
     private JPanel buttonPanel, etcPanel;
      * Calls:     readStudentNames, setUpImages
     public void init(){
          readStudentNames();
          setUpImages();
          setLayout(new BorderLayout());
          setSize(500,670);
          etcPanel = new JPanel(new BorderLayout());
          refreshButton = new JButton("Refresh");
          deleteButton = new JButton("Delete");
          buttonList.reset();
          etcPanel.add("West", refreshButton);
          etcPanel.add("East", deleteButton);
          add("North", buttonPanel);
          add("South", etcPanel);
          refreshButton.addActionListener(this);
          deleteButton.addActionListener(this);
      * Pre:          students.dat in current directory
      *                studentList instantiated
      * Post:     studentList has Student objects with names, not images(yet)
      * Purpose:     to set up studentList with student names
     private void readStudentNames(){
          try {
               FileReader dataInput = new FileReader("students.dat");
               input = new Scanner(dataInput);
          } catch (FileNotFoundException e) {
               System.err.println("ERROR:Students.dat file not found");
               e.printStackTrace();
          studentsList = new RefSortedList();
          while(input.hasNextLine()){
               String studentName = input.nextLine();
              studentVar = new Student(studentName);
               studentsList.add(studentVar);
          System.out.println(studentsList + "");
     }//readStudentNames()
      * Pre:          studentList set up with names
      *                .jpg files are in current directory
      * Post:     buttons set up with images in buttonList and buttonPanel
      * Purpose:     to set up buttons with Student names and images
     private void setUpImages(){
          ImageIcon studentPic;
          Student studentStringPic;
          studentsList.reset();
          buttonList = new RefUnsortedList();
          buttonPanel = new JPanel(new GridLayout(5,3));
          for (int k = 0; k < studentsList.size(); k++) {
               studentPic = new ImageIcon(studentVar.toString() + ".jpg");
               studentStringPic = new Student(studentVar.toString(), studentPic);
               b = new JButton(studentStringPic.toString(), studentStringPic.getIcon());
               b.setVerticalTextPosition(AbstractButton.BOTTOM);
              b.setHorizontalTextPosition(AbstractButton.CENTER);
               b.addActionListener(this);
               buttonList.add(b);
              buttonPanel.add(b);
               studentsList.getNext();
      * Pre:          buttonList set up
      * Post:     All buttons enabled
      * Purpose:     To enable all buttons in buttonList
     public void refreshImages(){
          for(int i=0;i<buttonList.size();i++){
               b.setEnabled(true);
               buttonList.getNext();
     * Pre:     buttonPanel, buttonList set up
     * Post:    disabled buttons removed from buttonPanel
     * Purpose: To delete those students whose buttons are disabled
    private void deleteStudents(){
         for(int k=0; k<buttonList.size();k++){
              if(!b.isEnabled())
                   buttonPanel.remove(b);
              buttonList.getNext();
         this.repaint();
     public void actionPerformed(ActionEvent e) {
          JButton b = (JButton) e.getSource();
          if(e.getSource() == deleteButton){
               deleteStudents();
          else if(e.getSource() == refreshButton){
               refreshImages();
          else{
               b.setEnabled(false);
}Student Class:
public class Student implements Comparable{
     private String name;
     private Icon icon;
     public Student(String nameT){
          name = nameT;
     public Student(String nameT, Icon iconT){
          name = nameT;
          icon = iconT;
     public int compareTo(Object arg0) {
          if(this.equals(name))
               return 1;
          else
               return -1;
     }//compareTo()
     public boolean equals(){
          boolean equalTo = false;
          if(this.equals(name))
               equalTo = true;
          return equalTo;
     }//equals()
      * Pre: LL is instantiated and filled
      * Post: none
      * Purpose: return the name of the student
     public String toString(){
          return name;
     }//toString()
     public Icon getIcon(){
          return icon;
}

I fixed the other things, I just need to fix two more problems and then clean up my code so it looks more professional.
First problem: When I add the Student variables to the studentsList, they aren't sorted. I think this is because they aren't being read as Strings and so there's no way to compare them. I could just do studentVar.toString(), but then studentsList would be full of Strings and not Students. Any ideas?
      * Pre:          students.dat in current directory
      *                studentList instantiated
      * Post:     studentList has Student objects with names, not images(yet)
      * Purpose:     to set up studentList with student names
     private void readStudentNames(){
          try {
               FileReader dataInput = new FileReader("students.dat");
               input = new Scanner(dataInput);
          } catch (FileNotFoundException e) {
               System.err.println("ERROR:Students.dat file not found");
               e.printStackTrace();
          studentsList = new RefSortedList();
          while(input.hasNextLine()){
               String studentName = input.nextLine();
              studentVar = new Student(studentName);
               studentsList.add(studentVar);
          System.out.println(studentsList + "");
     }//readStudentNames()Here's the add() method of RefSortedList:
public void add(Comparable element)
// Adds element to this list.
    LLObjectNode prevLoc;     // trailing reference
    LLObjectNode location;    // traveling reference
    Comparable listElement;   // current list element being compared
    boolean moreToSearch;
    // Set up search for insertion point.
    location = list;
    prevLoc = null;
    moreToSearch = (location != null);
    // Find insertion point.
    while (moreToSearch)
      listElement = (Comparable)location.getInfo();
      if (listElement.compareTo(element) < 0) // list element < add element
         prevLoc = location;
         location = location.getLink();
         moreToSearch = (location != null);   // stop looking at end of list
      else
        moreToSearch = false;     // list element >= add element
    // Prepare node for insertion.
    LLObjectNode newNode = new LLObjectNode(element);
    // Insert node into list.
    if (prevLoc == null)
      // Insert as first node.
      newNode.setLink(list);
      list = newNode;
    else
      // Insert elsewhere.
      newNode.setLink(location);
      prevLoc.setLink(newNode);
    numElements++;
}

Is there a way to fix ipod touch screen display problem with song list?

I was wondering if anybody has had this problem? I have an ipod touch 64gig 5th gen for probably about 2 years. I hardly use it because I have it as a back up ipod until primary one dies. This is the first time I came across this problem. Upon turning on device, the first artist/song list I choose displays correctly. Once I start choosing any other artist/song list afterwards, the display for the 1st artist/song list re-appears. If the song list is only a single song to 3-4 songs it will display correctly. Any other song list I choose that consist more than 5 songs, the first artist/song list re-appears on screen like the display is messed up.
For example: Upon turning on device, I choose Aaliyah with a list of 9 songs displaying.
Upon trying to select a different artist and song, for example I choose Nachtmar with a list of 20 songs.
The Aaliyah with the list of 9 songs re appears in place of the song list I am attempting to choose. The songs play and it works, but the display is incorrect. Why is it doing this? Does anybody have this problem? I have tried resetting and it has currently been updated. I have came across this problem just very recently a couple of days ago. I have had a couple of hard resets requiring to erase all data in the past and I don't want to go that way again because I have about 3,500 songs. I have never experience this problem before in the past. I just want it to display the current list of songs. It's inconvenient having to type in every song while playing in the car instead of being able to easily pick an individual song.

I have this problem too and it drives me crazy. When I view my ipod, I don't want to see a list of the first 8 songs in my ipod library. I just want to see the current song playing. It's like the ipod display goes into some type of "sleep" mode while your music plays,and the display defaults to show the first few songs in your ipod touch library, even though none of those songs are currently being played. I have to take the time to either flip the ipod over a couple of times in order for that list to disappear just to see the current song playing.
This is an example of what I see on my display after the current song begins playing. These are the first songs in my ipod library. To get rid of this view, I have to either shake the ipod or flip it over a couple of times and the current song is now displayed, allowing you to see the current song, also allowing you access to the arrows to either fast forward or playback/reverse. On the display, the songs are in a grid or table format (unable to show that here).
Acoustic Soul
Aaliyah
Adventers on the Wheels
Adventures in Paradise
After Tonight
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Anyone having a problem with links in Safari after upgrading?

okay, Before the upgrade to os5, we were able to go to the website to get the e-edition of our local paper. The way their website is designed you first see part of the first page and then there is a link to take you to the full page. Everything worked just fine. Then after the upgrade, last Saturday, i am able to get the first part of the page, but when I click on the link to access the full page it goes to a blank page -about:blank. I do have safari on my laptop (an ibm) and the link works fine there. Is it a problem with Safari, the settings on my ipad or what? Please help?

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