Problems with Static and non-static stuff

Right now I am trying to work on a RPG and trying to make it all using classes instead of having a Applet run everything and want to call Methods to make / remove the buttons here is the Method I'm dealing with
    public void placeButtons()
        attackBtn.setBounds(200,700,75,25);
        defendBtn.setBounds(200,725,75,25);
        magicBtn.setBounds(275,700,75,25);
        itemBtn.setBounds(275,725,75,25);
        game.add(attackBtn);   // Here is where I am having the problem (non-static method add(java.awt.Component) cannot be referenced from a static context)
        attackBtn.addActionListener(this);
    }Normally I would be making all my buttons in my main class but I want to know if I can make them in a separate class and load them in my main class so I can shorten my code by a ton.

Generally speaking: Yes: you are only limited by your ingenuity and knowledge.
//call from other class
MyButtonClass mbc = new MyButtonClass();
MyPanel p = new MyPanel();
p.add(mbc.getMyMainButton());
//what everAlthough I would think that it may be better to get your entire Frame back for display or a panel... It just seems like it's going to be awkward to work with unless you're making some kind of button generator or something, but then it's your app and from your description, the code given should illustrate a way of getting to the answer you seek.

Similar Messages

Static and non-static variables and methods

Hi all,
There's an excellent thread that outlines very clearly the differences between static and non-static:
http://forum.java.sun.com/thread.jsp?forum=54&thread=374018
But I have to admit, that it still hasn't helped me solve my problem. There's obviously something I haven't yet grasped and if anyone could make it clear to me I would be most grateful.
Bascially, I've got a servlet that instatiates a message system (ie starts it running), or, according to the action passed to it from the form, stops the message system, queries its status (ie finds out if its actually running or not) and, from time to time, writes the message system's progress to the browser.
My skeleton code then looks like this:
public class IMS extends HttpServlet
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
        doPost(request, response);
   public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
      //get the various parameters...
         if (user.equalsIgnoreCase(username) && pass.equalsIgnoreCase(password))
            if(action.equalsIgnoreCase("start"))
                try
                    IMSRequest imsRequest = new IMSRequest();
                    imsRequest.startIMS(response);
                catch(IOException ex)
                catch(ClassNotFoundException ex)
            else if(action.equalsIgnoreCase("stop"))
                try
                    StopIMS stopIMS = new StopIMS();
                    stopIMS.stop(response);
                catch(IOException ex)
             else if(action.equalsIgnoreCase("status"))
                try
                    ViewStatus status = new ViewStatus();
                    status.view(response);
                catch(IOException ex)
         else
            response.sendRedirect ("/IMS/wrongPassword.html");
public class IMSRequest
//a whole load of other variables
public PrintWriter    out;
    public int                 messageNumber;
    public int                 n;
    public boolean         status = false; //surely this is a static variable?
    public String            messageData = ""; // and perhaps this too?
    public IMSRequest()
    public void startIMS(HttpServletResponse response) throws IOException, ClassNotFoundException
        try
            response.setContentType("text/html");
            out = response.getWriter();
            for(n = 1 ; ; n++ )
                getMessageInstance();
                File file = new File("/Users/damian/Desktop/Test/stop_IMS");
                if (n == 1 && file.exists())
                    file.delete();
                else if (file.exists())
                    throw new ServletException();
                try
                    databaseConnect();
               catch (ClassNotFoundException e)
//here I start to get compile problems, saying I can't access non-static methods from inside a static method
               out.println(FrontPage.displayHeader());
                out.println("</BODY>\n</HTML>");
                out.close();
                Thread.sleep(1000);
        catch (Exception e)
    }OK, so, specifially, my problem is this:
Do I assume that when I instantiate the object imsRequest thus;
IMSRequest imsRequest = new IMSRequest();
imsRequest.startIMS(response); I am no longer in a static method? That's what I thought. But the problem is that, in the class, IMSRequest I start to get compile problems saying that I can't access non-static variables from a static method, and so on and so on.
I know I can cheat by changing these to static variables, but there are some specific variables that just shouldn't be static. It seems that something has escaped me. Can anyone point out what it is?
Many thanks for your time and I will gladly post more code/explain my problem in more detail, if it helps you to explain it to me.
Damian

Can I just ask you one more question though?Okay, but I warn you: it's 1:00 a.m., I've been doing almost nothing but Java for about 18 hours, and I don't do servlets, so don't take any of this as gospel.
If, however, from another class (FrontPage for
example), I call ((new.IMSRequest().writeHTML) or
something like that, then I'm creating a new instance
of IMSRequest (right?)That's what new does, yes.
and therefore I am never going
to see the information I need from my original
IMSRequest instance. Am I right on this?I don't know. That's up to you. What do you do with the existing IMS request when you create the new FrontPage? Is there another reference to it somewhere? I don't know enough about your design or the goal of your software to really answer.
On the other hand, IMSRequest is designed to run
continuously (prehaps for hours), so I don't really
want to just print out a continuous stream of stuff to
the browser. How can I though, every so often, call
the status of this instance of this servlet?One possibility is to pass the existing IMSRequest to the FrontPage and have it use that one, rather than creating its own. Or is that not what you're asking? Again, I don't have enough details (or maybe just not enough functioning brain cells) to see how it all fits together.
One thing that puzzles me here: It seems to me that FP uses IMSReq, but IMSReq also uses FP. Is that the case? Those two way dependencies can make things ugly in a hurry, and are often a sign of bad design. It may be perfectly valid for what you're doing, but you may want to look at it closely and see if there's a better way.

Abstract method versus static and non-static methods

For my own curiosity, what is an abstract method as opposed to static or non-static method?
Thanks

>
Following this logic, is this why the "public static
void main" 0r "Main" method always has to be used
before can application can be run: because it belongs
to the class (class file)?
Yes! Obviously, when Java starts up, there are no instances around, so the initial method has to be a static (i.e. class) one. The name main comes from Java's close association with C.
RObin

Problem with Threads and a static variable

I have a problem with the code below. I am yet to make sure that I understand the problem. Correct me if I am wrong please.
Code functionality:
A timer calls SetState every second. It sets the state and sets boolean variable "changed" to true. Then notifies a main process thread to check if the state changed to send a message.
The problem as far I understand is:
Assume the timer Thread calls SetState twice before the main process Thread runs. As a result, "changed" is set to true twice. However, since the main process is blocked twice during the two calls to SetState, when it runs it would have the two SetState timer threads blocked on its synchronized body. It will pass the first one, send the message and set "changed" to false since it was true. Now, it will pass the second thread, but here is the problem, "changed" is already set to false. As a result, it won't send the message even though it is supposed to.
Would you please let me know if my understanding is correct? If so, what would you propose to resolve the problem? Should I call wait some other or should I notify in a different way?
Thanks,
B.D.
Code:
private static volatile boolean bChanged = false;
private static Thread objMainProcess;
   protected static void Init(){
        objMainProcess = new Thread() {
            public void run() {
                while( objMainProcess == Thread.currentThread() ) {
                   GetState();
        objMainProcess.setDaemon( true );
        objMainProcess.start();
    public static void initStatusTimer(){
        if(objTimer == null)
             objTimer = new javax.swing.Timer( 1000, new java.awt.event.ActionListener(){
                public void actionPerformed( java.awt.event.ActionEvent evt){
                          SetState();
    private static void SetState(){
        if( objMainProcess == null ) return;
        synchronized( objMainProcess ) {
            bChanged = true;
            try{
                objMainProcess.notify();
            }catch( IllegalMonitorStateException e ) {}
    private static boolean GetState() {
        if( objMainProcess == null ) return false;
        synchronized( objMainProcess ) {
            if( bChanged) {
                SendMessage();
                bChanged = false;
                return true;
            try {
                objMainProcess.wait();
            }catch( InterruptedException e ) {}
            return false;
    }

Thanks DrClap for your reply. Everything you said is right. It is not easy to make them alternate since SetState() could be called from different places where the state could be anything else but a status message. Like a GREETING message for example. It is a handshaking message but not a status message.
Again as you said, There is a reason I can't call sendMessage() inside setState().
The only way I was able to do it is by having a counter of the number of notifies that have been called. Every time notify() is called a counter is incremented. Now instead of just checking if "changed" flag is true, I also check if notify counter is greater than zero. If both true, I send the message. If "changed" flag is false, I check again if the notify counter is greater than zero, I send the message. This way it works, but it is kind of a patch than a good design fix. I am yet to find a good solution.
Thanks,
B.D.

Help with static and non static references

Hi all,
I'm new to Java I'm having some difficulties with accessing non static methods.
I'm working with Tree data structures and all the interfaces and methods are non-static.
I have to write a tester main method to create and modify trees but how do I access the non static fields from main which is static?
Any help would be appreciated
Thanks.

Create an Instance for that particular class then call the method using that instance.

Problems with SMD and Non-ABAP EW Alerts

Hi,
Iu2019m installing Solution Manager Diagnostics EhP1. Iu2019ve installed SMD Agent at my satellite systems and created the system and the solution at Solution Manager EhP1 SP21 (SMSY and DSWP transactions), but when I try to execute at Solution Manager Diagnostics (http:<server>:<port>/sld) managed systems -> setup wizard for my managed systems, I got the following error:
u201CNo instances or servers are defined for this system. Please check its definition in SMSY before proceeding to setupu201D
If I try to open up the system I realise that the Landscape collumn is red-rated and shows:
Start checking Technical System 'EPD~JAVA'. (green-rated)
No Hosts found! (red-rated)
The Technical System is not well defined! (red-rated)
Iu2019ve maintained properly SMSY transaction, and defined servers and instances for Application Server Java, EP Content, EP Core and Enterprise Portal.
On the other hand, Iu2019ve followed SAP Note 976054 and itu2019s attached file, which types that I can schedule an EW Alert for Non-ABAP trhough DSWP transaction -> Solution->Solution Reporting->Services->Activities->Scheduling Reporting.
If I schedule the job and try to execute, the job is cancelled and the job log types this:
Date       Time     Message text                                                               Message class Message no. Message type
18.11.2009 14:03:30 Job started                                                                     00           516          S
18.11.2009 14:03:30 Step 001 started (program RDSWP_REP_SERVICES, variant , user ID SOLMANADM)      00           550          S
18.11.2009 14:03:30 Table (22x9) exported as attachment 1000000000005; 1.570 bytes                 DSWP          857          S
18.11.2009 14:03:30 No layouts found                                                                0K           017          E
18.11.2009 14:03:30 Job cancelled after system exception ERROR_MESSAGE                              00           564          A
At the same word file, it shows that I can download an XML file wich contain all data required for the service in question and upload it into a service session for direct evaluation.
When I try to go to Managed systems->Scheduler, I notice that this section doesnu2019t appear at my Solution Manager Diagnostics. I only have setup options for Diagnostics system and managed systems.
So I resume my main problems:
1 When I try to setup an managed system I get a pop up u201CNo instances or servers are defined for this system. Please check its definition in SMSY before proceeding to setupu201D
2 When I try to execute SM_REP:XXXXXXX job itu2019s cancelled
3 When I try to get an XML file for direct evaluation, Iu2019m unable to get to the option to execute it.
Please, could you help me?
Thanks in advance and regards,
Tomas.

Hello,
When you are clicking on the System in SMSY, do you get a message that this is a dual stack system and gives you a
choice with a dialog that has two buttons to select 'EPD~JAVA' or 'EPD-ABAP'?
Just if you are then you have not defined the system correctly in SMSY
Let me knwo if you get this dialog when you seelct the SID in SMSY.
Did you use the System Landscape Setup Guide to define your technical system?
Regards,
Paul

Problem with parameters and non table based items

Hi,
I have a situation where I have some not table based items on a page (shuttles and select lists). It is parameters that the end user inputs. I have another page with the same items just here they are Display Only and also not table based. When the user press a button I branch from page 1 to page 2 and set the items on page 2. My problem is that the input the user keys in are not copied to the items on page 2. I can see the data in the session state.
I assume that this is a silly question and I have just set Source Used or Source Type wrong one one of the items but I can not get it working. Can anybody help?
It works fine if I use a Application Item and creates a process on page 1 where I copy the item value from the session state but that should be needed right?
Regards Pete

Thanks Scott,
I think I got it working. If I remove all the colons from the data it works. I select several entries in a Shuttle and the result is a colon delimited string of values. If I remove these in a process it works fine. Is there a way of escaping the output from a Shuttle?
Regards Pete

Problem with Vcard and non-English character

VCard feature is what I would like to use, but I have quite a few contacts with Non-English name (Korean).
I know Ipod can display in Korean, but when I create a v-card with Korean character and copy the vcard file over into /contacts folder, I can see the filename as the person's name (From windows explorer), but I can ONLY see first character of the file when I display contacts in iPod.
Does anyone have tips/tricks on displaying all the filename in IPod contacts?
Thanks.
Windows XP Pro

Because i use the string nota into a jsp page and i print the string nota into a textarea and the text is with no newline, example:
<textarea name="nota" rows="4" cols="60"><%= nota %></textarea>
the text into textarea is:
first linesecond linethird line
but i want that the text displayed into textarea is equal the text into the CDATA section:
first line
second line
third line

I have had problems with slow and non-responding Internet using Safari.

While my Windows-based laptop and iPhone access the Internet fine, we are having difficulties with our iMac accessing the Internet and, if we do get on, it is extremely slow.

If you mean movies you have exported from iMovie HD, those can be imported easily. If you mean iMovie HD projects opening in iMovie '11, I don't see many people have much success with that.

Static variable and non-static

I have a quick question. The following syntax compiles.
private String t = key;
private static String key = "key";
But this doesn't compile.
private String t = key;
private String key = "key";
Can anybody explain how it is treated in java compiler?
Thanks.

jverd wrote:
doremifasollatido wrote:
I understand that completely. I didn't say that the OP's version with static didn't work. I was just giving an alternative to show that you don't need static, if you change the order that the instance variables are declared.My problem with the underlined is that, while technically true, I can see where a newbie would take it as "oh, so that's how I can get rid of static," and focus only on how to satisfy the compiler, rather than on learning a) when it's appropriate to make something static or not from a design perspective, and b) what the implications of that decision are, for both static and non.
I have just a wee bit of a prejudice against the "what do I type to make the error messages go away" approach. :-)That sounds good to me. We're currently trying to fix an issue caused by the fact that one class has most of its variables as static, when they should really be instance variables. There should only be one active instance of this class at a time, but the values of the static variables stick around when you call "new ThisClass()". So, old data interferes with new data, and various errors happen. The class has many static methods to access the static variables, but it should have been more of a Singleton--an actual object with non-static variables. The active instance of the Singleton would need to be replaced at logout/login (as opposed to shutdown completely and restart the JVM), but then at least when the new instance were created, then all of the variables would be initialized to empty--the old instance would disappear. The solution at the moment (solution by others--I don't agree) is to clear each static Vector and then set the reference to null (setting to null would be enough to drop the old data, but certain people don't get that...). This is fragile because many variables were missed in this "cleanup" process, and it will be easy to forget to "cleanup" new variables in the future. This class has been misdesigned for years (much longer than I've been here). The calls to static methods permeate the application, so it isn't easy to fix it quickly. There are several of these misdesigned classes in our application--a mix of static and non-static, when nothing or almost nothing should be static.

Static vs Non--Static members

I'm having some trouble trying to understand the differences between static and non-static members.
I've read a few online information about static members, but I don't understand the purpose of static members.
Can someone try to explain the main points of static members and the differences between static and non-static members?

I'm having some trouble trying to understand the
differences between static and non-static members.
I've read a few online information about static
members, but I don't understand the purpose of static
members.
Can someone try to explain the main points of static
members and the differences between static and
non-static members?Static means only one per class. If you have a Class and generate 20 objects of this class or more, they all share the same copies of any static variables. This is as opposed to instance variables of which each Object has its own. If an object changes one of its instance variables, this doesn't affect another object's instance variables.
Having said this, however, vague and general questions are great if you are face to face with a tutor where you can have a conversation but are very difficult to answer in this format. Your best bet is to go through several online articles (and there are many good ones, just google for them) and then coming back with specific questions. Another option is to go through a book or two. Most have a chapter covering this.
Message was edited by:
petes1234

Problems with libraries and plugins - non admin account

I''ve got a couple of problems with a fresh install of photoshop on my windows Windows 7 64 bits system.
1. Libraries panel does not work. It displays the following error and interaction is not possible:
2. 3rd party plugins would load their content.
3. In the Creative Cloud Application the apps tab would load and displays the "download error" message:
The funny thing is that all the above errors don't occur on the loacl admin account. So I think this might be a permission problem. I think the most easy sollution would be to work under the admin account, but sadly that's no option (company policy). I am able to extent the rights of the useraccount I work on, but I don't know in wich folders the software needs write permissions. The both Adobe folders in program files and program files (x86) I already changed to full acces for all users. Can someone please help me?

Problems with libraries and plugins - non admin account https://forums.adobe.com/people/pippyn%20stortelder
This is a permissions Error. The other accounts on the computer do have permissions to use / change the administrator settings of these particular items.
There are two ways you can fix this. 1.) contact the admin of the system and let him know your accounts need read access to these items
My Preferred method is:
If you are on a Windows Account, then you can choose those items to run in Administrator mode for all people. ( win7,64bit )
Right click the infinity system for creative cloud (creative cloud icon - you would normally click to start the program. (not the one in your service tray, but the one in your menu area with the square red on it.
choose/click on properties
choose/click compatibility (tab at the top of the window)
Last boxed option on this screen is: Run Program As Administrator, Click that check box.
Click on Change Settings for All Users
in the window that comes up again choose, put an X in the box- the last option, Run Program As Administrator - Click Apply
Click OK
Click OK and the opened preferences window should now be closed.
You should be able to simply invoke the Cloud app now. But you might want to reboot to safe.
Depending on the installation methods used for your add-ons, you may have to perform this same process for all add-ins. I believe that would depend on which account, first installed the add-on and what level of permissions they have.
Good Luck
~elaine.

Problem with Thread and InputStream

Hi,
I am having a problem with threads and InputStreams. I have a class which
extends Thread. I have created and started four instances of this class. But
only one instance finishes its' work. When I check the state of other three
threads their state remains Runnable.
What I want to do is to open four InputStreams which are running in four
threads, which reads from the same url.
This is what I have written in my thread class's run method,
public void run()
     URL url = new URL("http://localhost/test/myFile.exe");
URLConnection conn = url.openConnection();
InputStream istream = conn.getInputStream();
System.out.println("input stream taken");
If I close the input stream at the end of the run method, then other threads
also works fine. But I do not want to close it becuase I have to read data
from it later.
The file(myFile.exe) I am trying to read is about 35 MB in size.
When I try to read a file which is about 10 KB all the threads work well.
Plz teach me how to solve this problem.
I am using JDK 1.5 and Win XP home edition.
Thanks in advance,
Chamal.

I dunno if we should be doing such things as this code does, but it works fine for me. All threads get completed.
public class ThreadURL implements Runnable
    /* (non-Javadoc)
     * @see java.lang.Runnable#run()
    public void run()
        try
            URL url = new URL("http://localhost:7777/java/install/");
            URLConnection conn = url.openConnection();
            InputStream istream = conn.getInputStream();
            System.out.println("input stream taken by "+Thread.currentThread().getName());
            istream.close();
            System.out.println("input stream closed by "+Thread.currentThread().getName());
        catch (MalformedURLException e)
            System.out.println(e);
            //TODO Handle exception.
        catch (IOException e)
            System.out.println(e);
            //TODO Handle exception.
    public static void main(String[] args)
        ThreadURL u = new ThreadURL();
        Thread t = new Thread(u,"1");
        Thread t1 = new Thread(u,"2");
        Thread t2 = new Thread(u,"3");
        Thread t3 = new Thread(u,"4");
        t.start();
        t1.start();
        t2.start();
        t3.start();
}And this is the o/p i got
input stream taken by 2
input stream closed by 2
input stream taken by 4
input stream closed by 4
input stream taken by 3
input stream closed by 3
input stream taken by 1
input stream closed by 1
can u paste your whole code ?
ram.

Problems with SwingWorker and classes in my new job, ;), can you help me?

Hi all, ;)
First of all, sorry about my poor English.
I have a problem with Swing and Threads, I hope you help me (because I'm in the firsts two weeks in my new job)
I have two classes:
Form1: Its a JPanel class with JProgressBar and JLabel inside.
FormularioApplet: (the main) Its a JPanel class with a form1 inside.
I have to download a file from a server and show the progress of the download in the JProgressBar. To make it I do this:
In Form1 I make a Thread that update the progress bar and gets the fole from the server.
In FormularioApplet (the main) I call to the method getDownloadedFile from Form1 to get the File.
THE PROBLEM:
The execution of FormularioApplet finishes before the Thread of Form1 (with download the file) download the file. Then, when I call in FormularioApplet the variable with the file an Exception: Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException is generated.
First main begins his execution, then call to Form1 (a thread) then continues his execution and when the execution is finished ends the execution os Form1 and his thread.
How can I do for main class call the function and the Thread download his file after main class assign the file of return method?
How can I pass information froma class include an a main class. Form1 can't send to main (because main class made a Form1 f1 = new Form1()) any information from his end of the execution. I think if Form1 can say to main class that he finishes is job, then main class can gets the file.
I put in bold the important lines.
Note: My level of JAVA, you can see, is not elevated.
THANKS A LOT
Form1 class:
package es.cambrabcn.signer.gui;
import java.awt.HeadlessException;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.StringTokenizer;
import java.util.Vector;
import javax.swing.SwingUtilities;
public class Form1 extends javax.swing.JPanel {
    //Variables relacionadas con la clase original DownloadProgressBar
    private InputStream file;
    private int totalCicles;
    private int totalFiles;
    private int currentProgress;
    private SwingWorker worker;
    private ByteArrayOutputStream byteArray;
    private boolean done;
    /** Creates new form prueba */
    public Form1() {
        initComponents();
        this.byteArray = new ByteArrayOutputStream();
        progressBar.setStringPainted(true);
        //this.totalFiles = totalFiles;
        currentProgress = 0;
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
    // <editor-fold defaultstate="collapsed" desc=" C�digo Generado ">
    private void initComponents() {
        label1 = new javax.swing.JLabel();
        progressBar = new javax.swing.JProgressBar();
        statusLabel = new javax.swing.JLabel();
        setBackground(new java.awt.Color(255, 255, 255));
        setMaximumSize(new java.awt.Dimension(300, 150));
        setMinimumSize(new java.awt.Dimension(300, 150));
        setPreferredSize(new java.awt.Dimension(300, 150));
        label1.setFont(new java.awt.Font("Arial", 1, 18));
        label1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        label1.setText("Barra de progreso");
        statusLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        statusLabel.setText("Cargando");
        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(org.jdesktop.layout.GroupLayout.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
                    .add(org.jdesktop.layout.GroupLayout.LEADING, statusLabel, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 280, Short.MAX_VALUE)
                    .add(org.jdesktop.layout.GroupLayout.LEADING, progressBar, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 280, Short.MAX_VALUE)
                    .add(org.jdesktop.layout.GroupLayout.LEADING, label1, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 280, Short.MAX_VALUE))
                .addContainerGap())
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .addContainerGap()
                .add(label1)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(progressBar, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(statusLabel)
                .addContainerGap(73, Short.MAX_VALUE))
    }// </editor-fold>
    // Declaraci�n de variables - no modificar
    private javax.swing.JLabel label1;
    private javax.swing.JProgressBar progressBar;
    private javax.swing.JLabel statusLabel;
    // Fin de declaraci�n de variables
    public byte[] getDownloadedFile(String documentToSign){
         //Variables locales
         byte puente[] = null;
         try{
            //Leemos el documento a firmar
            StringTokenizer st = new StringTokenizer(documentToSign, ";");
            Vector<URL> fileURL = new Vector<URL>();
            HttpSender sender = new HttpSender(null);
            //Introducimos la lista de URLs de archivos a bajar en el objeto Vector
            for(; st.hasMoreTokens(); fileURL.add(new URL(st.nextToken())));
            //Para cada URL descargaremos un archivo
            for(int i = 0; i < fileURL.size(); i++) {
                file = sender.getMethod((URL)fileURL.get(i));
                if(file == null) {
                    Thread.sleep(1000L);
                    throw new RuntimeException("Error descarregant el document a signar.");
                System.out.println("Form1 Dentro de getDownloadFile, Antes de startDownload()");
                //Fijamos el valor del n�mero de ciclos que se har�n seg�n el tama�o del fichero
                this.totalCicles = sender.returnCurrentContentLength() / 1024;
                this.progressBar.setMaximum(totalCicles);
                //Modificamos el texto del JLabel seg�n el n�mero de fichero que estemos descargando
                this.statusLabel.setText((new StringBuilder("Descarregant document ")).append(i + 1).append(" de ").append(fileURL.size()).toString());
                statusLabel.setAlignmentX(0.5F);
                *//Iniciamos la descarga del fichero, este m�todo llama internamente a un Thread*
                *this.startDownload();*
                *System.out.println("Form1 Dentro de getDownloadFile, Despu�s de startDownload()");*
                *//if (pane.showProgressDialog() == -1) {*
                *while (!this.isDone()){*
                    *System.out.println("No est� acabada la descarga");*
                    *if (this.isDone()){*
                        *System.out.println("Thread ACABADO --> Enviamos a puente el archivo");*
                        *puente = this.byteArray.toByteArray();*
                        *System.out.println("Form1 getDownloadFile() tama�o puente: " + puente.length);*
                    *else{*
                        *Thread.sleep(5000L);*
*//                        throw new RuntimeException("Proc�s de desc�rrega del document a signar cancel�lat.");*
        catch (HeadlessException e) {
                //javascript("onSignError", new String[] {
                //(new StringBuilder("UI: ")).append(e.getMessage()).toString()});
        e.printStackTrace();
        catch (MalformedURLException e) {
                //javascript("onSignError", new String[] {
                //(new StringBuilder("CMS: ")).append(e.getMessage()).toString()});
        e.printStackTrace();
        catch (HttpSenderException e) {
                //javascript("onSignError", new String[] {
                //(new StringBuilder("CMS: ")).append(e.getMessage()).toString()});
        e.printStackTrace();
        catch (InterruptedException e) {
                //javascript("onSignError", new String[] {
                //(new StringBuilder("CMS: ")).append(e.getMessage()).toString()});
        e.printStackTrace();
        //System.out.println("Form1 getDownloadFile() tama�o puente: " + puente.length);
        return puente;
    public void updateStatus(final int i){
        Runnable doSetProgressBarValue = new Runnable() {
            public void run() {
                progressBar.setValue(i);
        SwingUtilities.invokeLater(doSetProgressBarValue);
    public void startDownload() {
        System.out.println("Form1 Inicio startDownload()");
        System.out.println("Form1 Dentro de startDownload, antes de definir la subclase SwingWorker");
        System.out.println(done);
        worker = new SwingWorker() {
            public Object construct() {
                System.out.println("Form1 Dentro de startDownload, dentro de construct(), Antes de entrar en doWork()");
                return doWork();
            public void finished() {
                System.out.println("Form1 Dentro de startDownload, dentro de finished(), Antes de asignar done = true");
                System.out.println(done);
                done = true;
                System.out.println("Form1 Dentro de startDownload, dentro de finished(), Despu�s de asignar done = true");
                System.out.println(done);
                statusLabel.setText("Completado, tama�o del archivo: " + (byteArray.size() / 1024) + "KB");
        System.out.println("Form1 Dentro de startDownload, antes de worker.start()");
        worker.start();
        System.out.println("Form1 Dentro de startDownload, antes de salir de startDownload");
        System.out.println(done);
        System.out.println("Form1 Dentro de startDownload, despu�s de worker.start()");
     * M�todo doWork()
     * Este m�todo descarga por partes el archivo que es necesario descargar, adem�s de actualizar
     * la barra de carga del proceso de carga de la GUI.
    public Object doWork() {
        System.out.println("Form1 doWork() this.byteArray.size(): " + this.byteArray.size());
        try {
            byte buffer[] = new byte[1024];
            for(int c = 0; (c = this.file.read(buffer)) > 0;) {
                this.currentProgress++;
                updateStatus(this.currentProgress);
                this.byteArray.write(buffer, 0, c);
            this.byteArray.flush();
            this.file.close();
            this.currentProgress = totalCicles;
            updateStatus(this.currentProgress);
        } catch(IOException e) {
            e.printStackTrace();
        System.out.println("Form1 doWork() FINAL this.byteArray.size(): " + this.byteArray.size());
        //done = true;
        System.out.println("AHORA DONE = TRUE");
        return "Done";
    public boolean isDone() {
        return this.done;
FormularioApplet class (main)
package es.cambrabcn.signer.gui;
import java.awt.Color;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import java.security.Security;
import java.util.StringTokenizer;
import java.util.Vector;
import javax.swing.SwingUtilities;
import netscape.javascript.JSObject;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import sun.security.provider.Sun;
import be.cardon.cryptoapi.provider.CryptoAPIProvider;
public class FormularioApplet extends java.applet.Applet {
    //Variables globales
    int paso = 0;
    private static final String JS_ONLOAD = "onLoad";
    private static final String JS_ONLOADERROR = "onLoadError";
    private static final int SIGNATURE_PDF = 1;
    private static final int SIGNATURE_XML = 2;
    //private String signButtonValue;
    private int signatureType;
    private String documentToSign;
    private String pdfSignatureField;
    private Vector<String> outputFilename;
    private Color appletBackground = new Color(255, 255, 255);
    private Vector<byte[]> ftbsigned;
     * Initializes the applet FormularioApplet
    public void init(){
        try {
            SwingUtilities.invokeLater(new Runnable() {
            //SwingUtilities.invokeAndWait(new Runnable() {
            //java.awt.EventQueue.invokeAndWait(new Runnable() {
                public void run() {
                    try{
                        readParameters();
                        initComponents();
                    catch(FileNotFoundException e){
                        javascript(JS_ONLOADERROR, new String[] {
                            (new StringBuilder("Init: ")).append(e.getMessage()).toString()});
                        e.printStackTrace();
                    catch(IOException e) {
                        javascript(JS_ONLOADERROR, new String[] {
                            (new StringBuilder("Init: ")).append(e.getMessage()).toString()});
                        e.printStackTrace();
        catch (Exception e) {
            javascript(JS_ONLOADERROR, new String[] {
                (new StringBuilder("Init: ")).append(e.getMessage()).toString()});
            e.printStackTrace();
        javascript(JS_ONLOAD, null);
    /** This method is called from within the init() method to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
    // <editor-fold defaultstate="collapsed" desc=" C�digo Generado ">
    private void initComponents() {
        this.setSize(350, 450);
        appletPanel = new javax.swing.JPanel();
        jPanel1 = new javax.swing.JPanel();
        jTextField1 = new javax.swing.JLabel();
        jPanel2 = new javax.swing.JPanel();
        label = new javax.swing.JLabel();
        jPanel3 = new javax.swing.JPanel();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();
        setLayout(new java.awt.BorderLayout());
        appletPanel.setBackground(new java.awt.Color(255, 255, 255));
        appletPanel.setMaximumSize(new java.awt.Dimension(350, 430));
        appletPanel.setMinimumSize(new java.awt.Dimension(350, 430));
        appletPanel.setPreferredSize(new java.awt.Dimension(350, 430));
        jPanel1.setBackground(new java.awt.Color(255, 255, 255));
        jPanel1.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 102, 204)));
        jTextField1.setFont(new java.awt.Font("Arial", 1, 18));
        jTextField1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jTextField1.setText("SIGNATURA ELECTRONICA");
        org.jdesktop.layout.GroupLayout jPanel1Layout = new org.jdesktop.layout.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .add(jTextField1, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 308, Short.MAX_VALUE)
                .addContainerGap())
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .add(jTextField1, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 24, Short.MAX_VALUE)
                .addContainerGap())
        jPanel2.setBackground(new java.awt.Color(255, 255, 255));
        jPanel2.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 102, 204)));
        label.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        label.setIcon(new javax.swing.ImageIcon("C:\\java\\workspaces\\cambrabcn\\firmasElectronicas\\logo.gif"));
        org.jdesktop.layout.GroupLayout jPanel2Layout = new org.jdesktop.layout.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .add(label, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 308, Short.MAX_VALUE)
                .addContainerGap())
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .add(label)
                .addContainerGap(229, Short.MAX_VALUE))
        jPanel3.setBackground(new java.awt.Color(255, 255, 255));
        jPanel3.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 102, 204)));
        //this.jButton1.setVisible(false);
        //this.jButton2.setVisible(false);
        jButton1.setText("Seg\u00fcent");
        jButton1.setAlignmentX(0.5F);
        //Cargamos el primer formulario en el JPanel2
        loadFirstForm();
        //Modificamos el texto del bot�n y el contador de pasos.
        //this.jButton1.setText("Siguiente");
        //this.jButton1.setVisible(true);
        //this.jButton2.setVisible(true);
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
        jButton2.setText("Cancel\u00b7lar");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
        org.jdesktop.layout.GroupLayout jPanel3Layout = new org.jdesktop.layout.GroupLayout(jPanel3);
        jPanel3.setLayout(jPanel3Layout);
        jPanel3Layout.setHorizontalGroup(
            jPanel3Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(org.jdesktop.layout.GroupLayout.TRAILING, jPanel3Layout.createSequentialGroup()
                .addContainerGap()
                .add(jButton1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 94, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED, 112, Short.MAX_VALUE)
                .add(jButton2, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 102, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
        jPanel3Layout.setVerticalGroup(
            jPanel3Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(org.jdesktop.layout.GroupLayout.TRAILING, jPanel3Layout.createSequentialGroup()
                .addContainerGap()
                .add(jPanel3Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                    .add(jButton2)
                    .add(jButton1))
                .addContainerGap())
        org.jdesktop.layout.GroupLayout appletPanelLayout = new org.jdesktop.layout.GroupLayout(appletPanel);
        appletPanel.setLayout(appletPanelLayout);
        appletPanelLayout.setHorizontalGroup(
            appletPanelLayout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(org.jdesktop.layout.GroupLayout.TRAILING, appletPanelLayout.createSequentialGroup()
                .addContainerGap()
                .add(appletPanelLayout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
                    .add(org.jdesktop.layout.GroupLayout.LEADING, jPanel2, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .add(org.jdesktop.layout.GroupLayout.LEADING, jPanel1, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .add(org.jdesktop.layout.GroupLayout.LEADING, jPanel3, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addContainerGap())
        appletPanelLayout.setVerticalGroup(
            appletPanelLayout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(org.jdesktop.layout.GroupLayout.TRAILING, appletPanelLayout.createSequentialGroup()
                .addContainerGap()
                .add(jPanel1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(jPanel2, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(jPanel3, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
        add(appletPanel, java.awt.BorderLayout.CENTER);
    }// </editor-fold>
    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
        this.destroy();
    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        changeForms(this.paso);
    // Declaraci�n de variables - no modificar
    private javax.swing.JPanel appletPanel;
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JPanel jPanel3;
    private javax.swing.JLabel jTextField1;
    private javax.swing.JLabel label;
    // Fin de declaraci�n de variables
     * M�todo readParameters
     * M�todo que inicializa los valores de los par�metros internos, recibidos por par�metro.
    private void readParameters() throws FileNotFoundException, IOException {
         ???????????????? deleted for the forum
        addSecurityProviders();
     * M�tode loadFirstForm
     * Aquest m�tode carrega a jPanel2 el formulari que informa sobre la c�rrega dels arxius
    private void loadFirstForm(){
        //Form1 f1 = new Form1(stream, i + 1, fileURL.size(), sender.returnCurrentContentLength(), appletBackground);
        //Form1 f1 = new Form1(fileURL.size(), sender.returnCurrentContentLength());
        Form1 f1 = new Form1();
        //Lo dimensionamos y posicionamos
        f1.setSize(310, 150);
        f1.setLocation(10, 110);
        //A�adimos el formulario al JPanel que lo contendr�
        this.jPanel2.add(f1);
        //Validem i repintem el JPanel
        jPanel2.validate();
        jPanel2.repaint();
        //Descarreguem l'arxiu a signar
        *System.out.println("FormularioApplet Dentro de loadFirstForm(), antes de llamar a getDownloadFile()");*
        *byte obj[] = f1.getDownloadedFile(this.documentToSign);*
        if (obj == null){
            System.out.println("Lo que devuelve f1.getDownloadedFile(this.documentToSign) es NULL");
        else{
            System.out.println("Lo que devuelve f1.getDownloadedFile(this.documentToSign) NO es NULL");
            System.out.println("obj: " + obj.length);
        this.ftbsigned.add(obj);
        System.out.println("FormularioApplet Dentro de loadFirstForm(), despu�s de llamar a getDownloadFile()");
        //Indicamos que el primer paso ya se ha efectuado
        this.paso++;
     * M�tode changeForms
     * Aquest m�tode carrega a jPanel2 un formulari concret segons el valor de la variable global "paso"
    private void changeForms(int paso){
        /*A cada paso se cargar� en el JPanel y formulario diferente
         * Paso previo: Se realiza en la inicializaci�n, carga el formulario, descarga el archivo y muestra la barra de carga.
         * Case 1: Se carga el formulario de selecci�n de tipo de firma.
         * Case 2: Se carga el formulario de datos de la persona que firma.
        this.paso = paso;
        switch(paso){
            case 1:
                //Creamos un objeto de formulario (seleccion de tipo de firma)
                Form2 f2 = new Form2();
                //Lo dimensionamos y posicionamos
                f2.setSize(310, 185);
                f2.setLocation(10, 110);
                //Quitamos el formulario 1 y a�adimos el formulario 2 al JPanel
                this.jPanel2.remove(1);
                this.jPanel2.add(f2);
                //Validem i repintem el JPanel
                jPanel2.validate();
                jPanel2.repaint();
                //Modificamos el contador de pasos.
                this.paso++;
                break;
            case 2:
                //Creamos un objeto de formulario (seleccion de tipo de firma)
                Form3 f3 = new Form3();
                //Lo dimensionamos y posicionamos
                f3.setSize(310, 175);
                f3.setLocation(15, 130);
                //Quitamos el formulario 1 y a�adimos el formulario 3 al JPanel
                this.jPanel2.remove(1);
                this.jPanel2.add(f3);
                //Validem i repintem el JPanel
                jPanel2.validate();
                jPanel2.repaint();
                //Modificamos el texto del bot�n y el contador de pasos.
                this.jButton1.setText("Finalizar");
                this.paso++;
                break;
            default:
                //Finalizar el Applet
                //C�digo que se encargue de guardar el archivo en el disco duro del usuario
                break;
    private void addSecurityProviders() throws FileNotFoundException, IOException {
        Security.addProvider(new CryptoAPIProvider());
        if (signatureType == SIGNATURE_PDF) {
            Security.addProvider(new BouncyCastleProvider());
        else {
            Security.addProvider(new Sun());
    private File createOutputFile(String filename, int index) {
        return new File((String)outputFilename.get(index));
    protected Object javascript(String function, String args[]) throws RuntimeException {
        //Remove
        if (true) return null;
        try {
            Vector<String> list = new Vector<String>();
            if(args != null) {
                for(int i = 0; i < args.length; i++) {
                    list.addElement(args);
if(list.size() > 0) {
Object objs[] = new Object[list.size()];
list.copyInto(objs);
return JSObject.getWindow(this).call(function, objs);
} catch(UnsatisfiedLinkError e) {
e.printStackTrace();
throw new RuntimeException((new StringBuilder()).append(e).append("\nFunci�: ").append(function).toString());
} catch(Throwable e) {
e.printStackTrace();
throw new RuntimeException((new StringBuilder()).append(e).append("\nFunci�: ").append(function).toString());
return JSObject.getWindow(this).call(function, new Object[0]);
Edited by: Kefalegereta on Oct 31, 2007 3:54 AM
Edited by: Kefalegereta on Oct 31, 2007 4:00 AM

Look at iOS Troubleshooting Wi-Fi networks and connections http://support.apple.com/kb/TS1398
iPad: Issues connecting to Wi-Fi networks http://support.apple.com/kb/ts3304
iOS: Recommended settings for Wi-Fi routers and access points http://support.apple.com/kb/HT4199
Additional things to try.
Try this first. Turn Off your iPad. Then turn Off (disconnect power cord) the wireless router & then back On. Now boot your iPad. Hopefully it will see the WiFi.
Go to Settings>Wi-Fi and turn Off. Then while at Settings>Wi-Fi, turn back On and chose a Network.
Change the channel on your wireless router. Instructions at http://macintoshhowto.com/advanced/how-to-get-a-good-range-on-your-wireless-netw ork.html
Another thing to try - Go into your router security settings and change from WEP to WPA with AES.
How to Quickly Fix iPad 3 Wi-Fi Reception Problems
http://osxdaily.com/2012/03/21/fix-new-ipad-3-wi-fi-reception-problems/
If none of the above suggestions work, look at this link.
iPad Wi-Fi Problems: Comprehensive List of Fixes
http://appletoolbox.com/2010/04/ipad-wi-fi-problems-comprehensive-list-of-fixes/
Fix iPad Wifi Connection and Signal Issues http://www.youtube.com/watch?v=uwWtIG5jUxE
~~~~~~~~~~~~~~~
If any of the above solutions work, please post back what solved your problem. It will help others with the same problem.
 Cheers, Tom

Problem with JFrame and busy/wait Cursor

Hi -- I'm trying to set a JFrame's cursor to be the busy cursor,
for the duration of some operation (usually just a few seconds).
I can get it to work in some situations, but not others.
Timing does seem to be an issue.
There are thousands of posts on the BugParade, but
in general Sun indicates this is not a bug. I just need
a work-around.
I've written a test program below to demonstrate the problem.
I have the problem on Solaris, running with both J2SE 1.3 and 1.4.
I have not tested on Windows yet.
When you run the following code, three JFrames will be opened,
each with the same 5 buttons. The first "F1" listens to its own
buttons, and works fine. The other two (F2 and F3) listen
to each other's buttons.
The "BUSY" button simply sets the cursor on its listener
to the busy cursor. The "DONE" button sets it to the
default cursor. These work fine.
The "SLEEP" button sets the cursor, sleeps for 3 seconds,
and sets it back. This does not work.
The "INVOKE LATER" button does the same thing,
except is uses invokeLater to sleep and set the
cursor back. This also does not work.
The "DELAY" button sleeps for 3 seconds (giving you
time to move the mouse into the other (listerner's)
window, and then it behaves just like the "SLEEP"
button. This works.
Any ideas would be appreciated, thanks.
-J
import java.awt.BorderLayout;
import java.awt.Cursor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class BusyFrameTest implements ActionListener
private static Cursor busy = Cursor.getPredefinedCursor (Cursor.WAIT_CURSOR);
private static Cursor done = Cursor.getDefaultCursor();
JFrame frame;
JButton[] buttons;
public BusyFrameTest (String title)
frame = new JFrame (title);
buttons = new JButton[5];
buttons[0] = new JButton ("BUSY");
buttons[1] = new JButton ("DONE");
buttons[2] = new JButton ("SLEEP");
buttons[3] = new JButton ("INVOKE LATER");
buttons[4] = new JButton ("DELAY");
JPanel buttonPanel = new JPanel();
for (int i = 0; i < buttons.length; i++)
buttonPanel.add (buttons);
frame.getContentPane().add (buttonPanel);
frame.pack();
frame.setVisible (true);
public void addListeners (ActionListener listener)
for (int i = 0; i < buttons.length; i++)
buttons[i].addActionListener (listener);
public void actionPerformed (ActionEvent e)
System.out.print (frame.getTitle() + ": " + e.getActionCommand());
if (e.getActionCommand().equals ("BUSY"))
frame.setCursor (busy);
else if (e.getActionCommand().equals ("DONE"))
frame.setCursor (done);
else if (e.getActionCommand().equals ("SLEEP"))
frame.setCursor (busy);
try { Thread.sleep (3000); } catch (Exception ex) { }
frame.setCursor (done);
System.out.print (" finished");
else if (e.getActionCommand().equals ("INVOKE LATER"))
frame.setCursor (busy);
SwingUtilities.invokeLater (thread);
else if (e.getActionCommand().equals ("DELAY"))
try { Thread.sleep (3000); } catch (Exception ex) { }
frame.setCursor (busy);
try { Thread.sleep (3000); } catch (Exception ex) { }
frame.setCursor (done);
System.out.print (" finished");
System.out.println();
Runnable thread = new Runnable()
public void run()
try { Thread.sleep (3000); } catch (Exception ex) { }
frame.setCursor (done);
System.out.println (" finished");
public static void main (String[] args)
BusyFrameTest f1 = new BusyFrameTest ("F1");
f1.addListeners (f1);
BusyFrameTest f2 = new BusyFrameTest ("F2");
BusyFrameTest f3 = new BusyFrameTest ("F3");
f2.addListeners (f3); // 2 listens to 3
f3.addListeners (f2); // 3 listens to 2

I've had the same problems with cursors and repaints in a swing application, and I was thinking of if I could use invokeLater, but I never got that far with it.
I still believe you would need a thread for the time consuming task, and that invokeLater is something you only need to use in a thread different from the event thread.

Problems with Static and non-static stuff

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