Sending HashMap over network

hi there,
Is there any way I can get around this HashMap bug?
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4756277
I tried to write a HashMap object over a network and the following exception was generated:
java.io.NotSerializableException: java.util.HashMap$EntrySet
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1156)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326)
Regards,

Due to this bug you can't use serialization mechanism on HashMap. A workaround should be to implement a SerializedHashMap class which extends HashMap and reimplement method for serialization. Methods to reimplement are:private void writeObject (java.io.ObjectOutputStream out) throws IOException;and
private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException;You can found useful tips of about write your code here: java.sun.com/docs/books/tutorial/essential/io/objectstreams.html

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Urgent help:send image over network using rmi

hi all,
i have few question about send image using rmi.
1) should i use ByteArrayOutputStream to convert image into byte array before i send over network or just use fileinputstream to convert image into byte array like what i have done as below?
public class RemoteServerImpl extends UnicastRemoteObject implements RemoteServer
public RemoteServerImpl() throws RemoteException
public byte[] getimage() throws RemoteException
    try{
       // capture the whole screen
       BufferedImage screencapture = new Robot().createScreenCapture(new     Rectangle(Toolkit.getDefaultToolkit().getScreenSize()) );
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       File file = new File("screencapture.jpg");
       ImageIO.write(screencapture, "jpg", file);
        byte[] fileByteContent = null;
       fileByteContent = getImageStream("screencapture.jpg");
       return fileByteContent;
    catch(IOException ex)
public byte[] getImageStream(String fname) // local method
    String fileName = fname;
    FileInputStream fileInputStream = null;
    byte[] fileByteContent = null;
      try
        int count = 0;
        fileInputStream = new FileInputStream(fileName); // Obtains input bytes from a file.
        fileByteContent = new byte[fileInputStream.available()]; // Assign size to byte array.
        while (fileInputStream.available()>0)   // Correcting file content bytes, and put them into the byte array.
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           count++;
       catch (IOException fnfe)
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}2)if what i done is wrong,can somebody give me guide?else if correct ,then how can i rebuild the image from the byte array and put it in a JLable?i now must use FileOuputStream but how?can anyone answer me or simple code?
thanks in advance..

Hi! well a had the same problem sending an image trough RMI.. To solve this i just read the image file into a byte Array and send the array to the client, and then the client creates an imegeIcon from the byte Array containing the image.. Below is the example function ton read the file to a byte Array (on the server) and the function to convert it to a an imageIcon (on the client).
//      Returns the contents of the file in a byte array.
    public static byte[] getBytesFromFile(File file) throws IOException {
        InputStream is = new FileInputStream(file);
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        long length = file.length();
        // You cannot create an array using a long type.
        // It needs to be an int type.
        // Before converting to an int type, check
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        if (length > Integer.MAX_VALUE) {
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        byte[] bytes = new byte[(int)length];
        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < bytes.length
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            offset += numRead;
        // Ensure all the bytes have been read in
        if (offset < bytes.length) {
            throw new IOException("Could not completely read file "+file.getName());
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public byte[] getImage(){
byte[] imageData;
          File file = new File("pic.jpg");
          // Change pic.jpg for the name of your file (duh)
          try{
               imageData = getBytesFromFile(file);
               // Send to client via RMI
                        return imageData;
          }catch(IOException ioe){
                       // Handle exception
                       return null; // or whatever you want..
}and then on the client you could call a function like this
public ImageIcon getImageFromServer(){
     try{
          // get the image from the RMI server
          byte[] imgBytes = myServerObject.getImage();
          // Create an imageIcon from the Array of bytes
          ImageIcon ii = new ImageIcon(imgBytes);
          return ii;
     }catch(Exception e){
          // Handle some error..
          // If yo get here probably something went wrong with the server
          // like File Not Found or something like that..
          e.printStackTrace();
          return null;
}Hope it helps you..

Sending images over network socket

I'm working on a java web server. So far i have managed to get it to send html documents sucessfully to the client web browser, using a BufferedReader, and a PrintWriter object.
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Thanks in advance.
hornetau

I did it first. You may pay me $10 and get XM2 WebServer 1.2 from my company.
Ok, I'll help ya out here...
HTTP protocol in Internet Explorer is "juiced up" meaning that it does not require HTTP data to be correctly sent. To send an image to be deisplayed...
<html>
<img src="theImage.gif"></img>
</html>
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Vishal,
Couple of questions.
How are you sending this message. Is it a message that you create and send Internally with an attachment.
As you reply me, please also check if the <b>Attachments folder</b> has been set under <b>Administration > System Initialization > General Settings.....Path Tab</b>
SBO tries to copy the attachment from the location you select to the Path defined for Attachments.
Let me know
Suda

Client/server - sending ArrayList over network

Hi all
I have have written a multithreaded client/server application where multiple clients connect to the server. For each client, the server spawns a new thread to handle the connected client. When a client connects to the server, the client sends its name to the server. The server stores the name in an ArrayList and sends the whole ArrayList to all the connected clients.
It worked fine a few days ago. But now I have a problem: When I send the ArrayList to all the connected clients then only the newly connected client gets the updated ArrayList while the previously connected clients get the ArrayList that they got previously i.e. they are not updated. If instead of sending an ArrayList, I just send the name of the newly connected client to all other connected clients then it works i.e. each client gets updated with that name. It also works fine if I just send an Integer value to all the clients upon a new connection.
I know the ArrayList implements Serializable, but I dont know how it doesnt work anymore!
Plz help me with this. I have been trying all combinations, but no luck so far.
thank you
taurean

thank you jwentling
to make sure that we are on the same page, here is the relevant code.
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Note: con.getInputStream() returns ObjectInputStream.
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Has it to do something with the stream? I mean could it be that the list is still in the stream (as you pointed out) and instead of the updated list, i just get the one from the stream that i got initially?!
thank you for ur time

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BB Europe say they have not got an issues at present.
Who is telling the truth?

I've been chatting off and on all week with friends in Europe, first I've heard of any anthing being down.
Do a simple reboot on the BlackBerry in this manner: With the BlackBerry device POWERED ON, remove the battery for a minute, and then reinsert the battery to reboot. A reboot in this manner is prescribed for most glitches and operating system errors, and you will lose no data on the device doing this.
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Sending Video over the wireless network

I am considering capturing images from a IEEE 1394 camera and sending it over the Wireless network to another computer. The reason we want to do that is to make the
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Hello Cindy,
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that same search and is titled Transfer Images Over the Network
which actually gives examples
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I cannot send email over 3G. Receiving email is ok. Using wifi from my landfibre allows me to send email. No idea where to find the solution. Suggestions please. Thanks ia

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TheOne

You need a DATA service enabled by your carrier to be able to send e-mail via thier network. Do you have a data plan with your carrier ? If so - is it enabled ?
Can you access internet thru your network (not wifi) ?

Why is my iPhone 5 sending data over cellular while on wifi using Vodafone Germany?

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I know that this is a common mistake on verizon iphone 5. i have the same problem with my iPhone 5 in Germany. It keeps sending data over cellular while I am on wifi. The wifi connection itself works though, even when I turn off cellular data. So my wifi is not broken.
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So this is really annoying me and I hope that Apple will fix this or one of you guys can help me.
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You may have a problem with your WiFi network if your iPhone can't stay connected to it.
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Problem sending mail over GPRS/EDGE

problem sending mail over GPRS/EDGE
i am in thailand right now with my iPhone 3G 16 GB (italian, no SIM-lock, 2.2). my problem: the iPhone does not send emails via GPRS/EDGE of local AIS mobile provider (there is no 3G in thailand right now). each time i try, i will get a prompt saying 'cannot send mail, the connection to the outgoing server "mail.gmx.net" failed'.
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ok. i found the solution.
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Sending File Over Serial PORT

Hi,
I'm able to read/write data over serial port using Java Comm APIs in Linux.
Can anybody please tell me how to write/read a file over Serial port?
Is it similar to sending a file over network?
An early response is appreciated...

Same stream I/O as used over the port works from a file. Dead simple.
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Hello, I am planning a highly interactive web-oriented application (a control panel). I have considered implementing it with pure HTML+JSP, possibly with some AJAX, but I don't really have the time to learn the AJAX toolkits out there, not does it seem fully worth it for this app.
The best solution would be to use a Java Applet, since it's easy to build a GUI in today's IDEs, and it integrates well with what I know. The problem is, this application must access an SQL database and possibly some other "private" classes that I don't want anyone snooping in. I could learn how to manaully send data over the HTTP connection from the applet, maybe even using tricks to asychronously perform this, but things become a bit confusing, and hard to scale.
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It'd be nice if I could specify code/classes to work client-side (i.e. "business logic"), to lower some networking load, but I may be getting a bit too wishful.
I am prepared to implement this myself, but I know a more robust and feature-rich AWT-stand-in API must already exist!
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I've been googling like crazy and sadly I've only come to two examples of what I'm talking about...but...
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Can not send mail over Edge

My boss has an original iPhone and I am constantly having problems keeping his e-mail functioning properly.
The latest issue is he can not send e-mail over the Edge network. I visited the AT&T support page, and they say to contact Apple for support.
Here is the message I get when attempting to send mail:
"Cannot send mail. One of the recipient addresses was invalid."
It is a POP account that works fine when sending mail over a wi-fi network. I have our smtp settings for our pop mail entered in his account as the main smtp server. There is also an additional server named AT&T SMTP Server.
When trying to send mail over the Edge network, I turn off the wi-fi access to force it to use the AT&T smtp server (cwmx.com) and every time I get the above error message.
I have another boss here with an identical iPhone and email settings that has no issues. The problem phone was brought to the local Apple Store and had the sim chip replaced, other than that they have no idea what is wrong.

My boss has an original iPhone and I am constantly having problems keeping his e-mail functioning properly.
The latest issue is he can not send e-mail over the Edge network. I visited the AT&T support page, and they say to contact Apple for support.
Here is the message I get when attempting to send mail:
"Cannot send mail. One of the recipient addresses was invalid."
It is a POP account that works fine when sending mail over a wi-fi network. I have our smtp settings for our pop mail entered in his account as the main smtp server. There is also an additional server named AT&T SMTP Server.
When trying to send mail over the Edge network, I turn off the wi-fi access to force it to use the AT&T smtp server (cwmx.com) and every time I get the above error message.
I have another boss here with an identical iPhone and email settings that has no issues. The problem phone was brought to the local Apple Store and had the sim chip replaced, other than that they have no idea what is wrong.

Can't send email over wi fi

I am not able to send email over the wi fi connection. I recieve it but can't respond or send an email that I compose. Also, I do not get the option to send from the general message folder even though it allows me to compose or reply from that location. I tried to get into the setup menu to check my email settings but it won't let me in there without connection to a mobil network, and I live in a dead spot, so the wi fi is critical. Do I have to go find a mobil connection to access these settings?

I'm glad you got it sorted. There may have been another option, though...see this page:
http://na.blackberry.com/eng/support/blackberry101/setup.jsp#tab_tab_email
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Now that you have it resolved, you should check out if your carrier presents BIS via a website...then you could do things with it when you are at home and out of their OTA signal area.
Good luck!
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.
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Hi, does anyone know why I cant send email over 3g but can over wi-fi. My provider is ntlworld

Hi, does anyone know why I cant send email over 3g but can over wi-fi. My provider is ntlworld. As soon as I get home and connect to wi-fi the mail sends no problem

We use ntlworld as our home broadband provider and main email address. In my experience ntl doesn't usually allow sending of email except on its own network which is why yours works at home. My iPhone is set up to send my ntl email using my second email account's smtp setting (in my case is is a mac.com account and I haven't found any network this doesn't work on to send email).
So my advice is to get yourself another email account with a different provider like yahoo or google, then use the new provider smtp address to send your ntl email on your iPhone.

Sending HashMap over network

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