SCTL-NFC1 is a Near Field Communication(NFC)/Radio Frequency Identification(RFID) Reader and Payment Adaptor designed for iPhone/iPod Touch to provide NFC two-way communication,RFID read/write and contactless payment capabilities.

SCTL-NFC1 is a Near Field Communication(NFC)/Radio Frequency Identification(RFID) Reader and Payment Adaptor designed for iPhone/iPod Touch to provide NFC two-way communication,RFID read/write and contactless payment capabilities.
commercial applications such as asset tracking, document tracking, healthcare, security and access control.

We are the manufactuer of the reader

Similar Messages

Error message saying "unable to establish two-way communication with device"

I have an HP C309a printer/scanner/fax. I have recently reconfigured it to work wirelessly instead of via the USB cable, which it does. But if I try to go on to the HP Solution Centre/Settings/Printer Toobox to clean the printheads, it tells me that this cannot be done because "the computer cannot establish two-way communication with the device".
If I plug the USB cable back in, I can clean the printheads fine.
Does anyone have a way of allowing me to clean the printheads without using the USB cable?
roger

Hi rogercorke,
I believe you can also clean the printhead from the printer control screen. Press the Wrench button from the printer Home screen and then press Tools>Clean Printhead.
If you need to use this feature wirelessly, try running the HP network diagnostic utility on your wireless setup and see what it says: http://h10025.www1.hp.com/ewfrf/wc/softwareDownloadIndex?cc=us&lc=en&jumpid=ex_r4155/en/hho/ipg/foru...
Please click the blue Kudos star in the post that helped you.

Question on PI like RFC,import maps,defining two ways communication

Hi Foks,
I am new to PI need information on the below issues.
1.How we can use RFC?
2.How to define Two way Communication eg:Remote system to ERP vise versa.
4.How ti transport the dev. object from Dev to Prod.
5.How we ca create the maps externally and import in PI is there any way we can do it.
Please help me out
shankar

How we can use RFC?
Import RFC in ESR/IR under IMPORTED OBJECTS that exist under software component in your ESR.
While importing RFC,you have to give system details from where you will import RFC in PI.
How ti transport the dev. object from Dev to Prod.
/people/sravya.talanki2/blog/2005/11/02/overview-of-transition-from-dev-to-qa-in-xi
/people/sap.india5/blog/2005/11/03/xi-software-logistics-1-sld-preparation
/people/sap.india5/blog/2005/11/09/xi-software-logistics-ii-overview
/people/sap.india5/blog/2005/11/28/xi-software-logistics-solution-iii-cms
thanks
Nidhi

The computer is unable to establish a two way communication with the device

Hi I am trying to fix a problem for some one else, and I am struggling where to look next. The issue is that we are unable to check the ink levels of a HP Deskjet 1050 printer. The error message states that the computer is unable to establish a two way communication with the device. After running through the troubleshooting guide about this issue on the HP site with no joy, I decided that it may be the printer and suggested a replacememnt. Unfortunately A new HP Envy 5530 was purchased and connected (wirelessly) but the issue remains. I have uninstalled the drivers multiple times, and also disabled any firewall/anti virus software in case this was interfering. I was hoping that some one could point me in the right direction next? None of the other forum posts here (or any google searches) give a solutuon which has fixed the problem. Thanks

No I cant. Unable to ping the printer too, not sure if this is possible normally?

How do i fix the inability to establish two-way communication between my computer and the printer?

HP Photosmart 5510 e-All in One Printer B111a
Windows XP
Message "The computer is unable to establish two-way communication with the device."
Installed new printer
I'm simply trying to get the estimated ink levels.

Please make a Genius Appointment and take it in for service.

Unable to establish the two way communication with printer j110a

every thing is ok but during the printing or ink level checking this message displayed "unable to establish the two way communication with printer j110a" please reply soon?

Hard Reset – While printer is powered ON, pull the power cord from the printer then from the wall. After 30 seconds reconnect power to wall and printer. This will trigger a ‘dirty power up’ and restore the printer to a known good condition (if it is possible). No user settings are lost with a ‘hard reset’. This ‘Hard Reset’ is one of the most powerful tools to use when the printer hardware is not functioning properly! IF NOT RESOLVED, uninstall hp software & reinstall using latest hp software from hp website.
Although I am working on behalf of HP, I am speaking for myself and not for HP.
Love Kudos! If you feel my post has helped you please click the White Kudos! Star just below my name : )
If you feel my answer has fixed your problem please click 'Mark As Solution' and make it easier for others to find help quickly : )
Happy Troubleshooting : )

Computer unable to establish two-way communication to J4580 through Airport Extreme

I have my J4580 connected to an Airport Extreme base station via usb. I've installed the printer software on my HP laptop (Vista) and Bonjour recognizes the printer as networked & installed, but when I try to print, i receive an error message "Computer is unable to establish two-way communication with the device" and the printer queue shows an error. I've attempted to find a solution through the posts, but haven't seen much that seems to apply to J4580. Any help??? Thanks!

I came across this similar problem and spent days trying to figure it out. I knew I was close when I tried to start the HPZ12
service and it kept failing with "unable to find the specified file". I traced it with a process monitor and found that it was looking
for a registry key that was not present. Specifically:
HKLM\System\CurrentCosntrolSet\Services\Pml Driver HPZ12\Parameters
It was looking for the string:
ServiceDLL which should be set to:
C:\WINDOWS\system32\HPZipm12.dll (or something similar)
The unfortunate thing is that no matter how many times you install and uninstall the HP drivers, then don't reset the registry keys
for the HPZ12 service. In the end, I ended up doing the following:
1. Uninstall software and reboot
2. Go through registry editor and delete the PML key (just did a search for all PML occurences)
3. Deleted the c:\program files\Hewlett-Packard directory
4. Deleted the c:\program files\HP directory
5. Deleted the c:\windows\system32\spool\drivers\w32x86\ contents (anything that referred to an HP printer or driver)
6. Deleted the HKLM\Software\Hewlett-Packard registry key
7. Rebooted
8. Reinstalled and everything worked.
I suggest you backup any registry keys prior to deleting them in case you make a mistake. You can use the Export feature on
the right-click context menu to save each key you delete, or use some tool to make a backup of your registry prior to making
these changes. Similarly, for the files, I renamed directories or created backups of their contents.
Once I reinstalled, I found that there were TONS of new registry keys added that weren't there before. So the real problem is
with HPs install/uninstall. It doesn't clean up properly and any aborted or failed instalation will leave the drivers in a poor state.

Unable to establish two-way communication with the printer

I have a HP Photosmart B8550 large format printer, but failed recently to print the whole page, but only one third of the page. The OS is Window 7 in my commuter. I downloaded the driver from HP website, but it is not working. The result of the failure is "The computer is unable to establish two-way communication with the device." One of the reasons I guess is that I failed to register my printer because I had no way to finish the registration, because there is no further process even if I put my printer name or number into the required block. Anyhow I failed recently to print anything in the printer. I am seeking the support after a lot of tries. Thanks.

I have two HP computers and two HP Photosmart B8550 printers. A month ago printers were not working. I tried in vain in two computers to download new HP software and driver from internet and got the HP Solution for install error - Windows 7. Based on this Solution on desk, I tried many many times to follow every step, but the result is the same: Fatal error during the installation.
By using other tools like HP Printer Diagnostic Tools, HP Print and Scan Doctor, I failed too because the diagosis or the choices are not accuate. For example, the printer is disconnected. It is wrong even if I changed ports and USB calbe again and again. The control panet can prove that there is communication, but the printer cannot work as directed. There is no way to test the printing as Doctor requested, saying the computer is unable to establish two-way communication with the device, which is not helpful to go ahead with the solution. There is no way to register the printer because there is no such a model HP Photosmart B8550 in its list after search.
It is even worse that the new window dialogue asked me to find HP Photosmart Essentials in my computer to install it again and again, and I could not concel the request whenever I open my computer.
I guess the HP printer software and driver has something wrong in its root design, which leads me to failure in installation so that the computer could not recognize my printer. In short, the new HP software and driver makes my printer not functional.
By the way, my two printers can work internally in printing sample paper and report and two computer are working in perfect condition.

I submitted my trade in and then placed order for iphone 6 - processed payment and everything - no email confirmation was sent and no order history on my acount - did it go through or not???

I submitted my trade in and then placed order for iphone 6 - processed payment and everything - no email confirmation was sent and no order history on my account - did it go through or not???

Seeyasoon,
I know this is something that I would be worrying about too, and I want to ease your mind. I've sent you a direct message and look forward to assisting you there.
SarahO_VZW
Follow us on Twitter @VZWSupport

Cannot print to my hp 7500. diagnostics says computer cannot establish two-way communication.?

cannot print to previously functional HP7500 on wireless network card. All reports from printer say everything is working fine (network card and printer), but computer says it cannot establish two-way communication. What do I do?

pcunning, I would recommend running this utility and seeing what it shows - or resolves:
http://goo.gl/u3jDE
Let me know!

Reply To field on iPhone/iPod Touch Mail?

Is there an option to provide a "Reply-To" field on the iPhone and iPod Touch versions of the email app? When i use mail on my iMac, the field is there when I create a new email message.
I am currently in my free-trial for MobleMe and for now, if I send an email from the iPhone. I'd like the reply-to to be set to my other email account (not the .me account).
Thanks,
Rick

Thanks. Just wanted to make sure I wasn't missing something.

Multi-threaded performance server using 2 ports to two-way communication

Hi, I'm new in the forums so welcome everyone. I'm developing now an online computer game based on orginal Polish board-game, but it doesn't mean. Important is that I need to develope a high-performance multi-threaded server, which can serve... let's say few hundres of games, and a thousend of players simulateously. My server works on two ports/sockets.
First one is represented by "ServerSocketChannel clientConSsc" in my code. The main thread in my server class which invokes the method "run()" (which You can see below), registers clientConSsc with Selector and then repeatingly accepts incoming connections from clients on this socket. When connection(channel) is estabilished and clients wants to write some request to this channel, the main thread on server creates a new instance of class "RequestHandler" which extends Thread and handles this request (reads the request from channel, makes some changes on server, spreads some new messages to other clients in the same game and so on... everything on the same socket/port/channel). Then the channel/connection is closed by the server - I call such connections: "a short connections". In the same time the main thread continues the loop and is still able to accept connections from another players. That's the idea of multi-threaded server, right? :) And to this point, everything works fine, but... what if the server wants to trigger some new command, write new information to client?
Server could have tried to open a SocketChannel to client's IP address, but then the client programme would have to create and ServerSocketChannel object, bind it to some InetAddress and then... and then client becomes a server! - that breaks the idea of client-server cooperation and demands on players of my game to have routed some port on their machines. To resolve this problem I made some sort of "system" which, when some player/client is logging into my server, accepts second (this time constant, not "short") connection on the second port I mentoined on the beginning. This connection is held in variable "SocketChannel serverCon" of class "Player" - which reflects a player logged onto server. Server maintains every such connection till the client logs off. After the connection is accepted, the player whom connection it was is added to collection called "playersToRegisterToWrite". After the Selector.selectNow() is invoked (as You can see in the code below), each and every player's connection is registered in selector (with selection key - OP_WRITE and attachment pointing on owning player). In the same time client's code is trying to read some bytes from this connection and blocks on it until some bytes are written to this connection. When server wants to "tell" something to client, deliver some message/command, it creates a new instance of class which extends an abstract class called "ServerAction" (another new thread) and adds it to collection "actionsToDo". In ServerAction's method "run()" there are whole code to interact with client (e.g. send an update of players' list, an update of games' list, a chat message). Finnaly when Selector informs the server that some connection is writable (some client is waiting for commands), then server checks if there's any "actionToDo" involving this client/player. If there is, it unregisters the connection from Selector (so no other ServerAction (thread) can write on this connection) and starts the action. At the end of every "run()" method of subclass of ServerAction there's a code, which again adds the player to collection "playersToRegisterToWrite", so the player's connection can again be registered in Selector and the player can again receive informations from server - after it consumed THIS "ServerAction".
It looks to me like it should be working fine, but it's not. When I test my server and clients on the same machine (no ping/latency) everything seems to be working fine. But when it comes to play my game with somebody even on LAN or through the Internet there comes the problems. My first socket I describe (and first type of connections - short connections) works perfectly fine, so the requests triggered by client are delivered and handled properly. But the second socket is cirppling. For example: the server triggers a command refering to an update of clients logged to server' list. It is triggered by Selector so the client should be ready to read data from server, so the server sends data! And the client never receives it... Why?
It experimented a whole lot of time on SocketChannel's method "configureBlocking(boolean)", but it never helps. I think the client should always block it's listening thread on connection, contratry to server which is ment to be fast, so it should send the data through non-blocking channels. Am I right? Are there any rules refering blocking configuration of SocketChannels?
I will be grateful for every answer. To help You out I attach also drafts from run()'s methods of my classes.
Server's main method - main thread :
    public void run() {
       try {
            selector = Selector.open();
            clientConSsc.configureBlocking(false);
            clientConSsc.register(selector , SelectionKey.OP_ACCEPT);
            while(serverRunning) {
                try {
                    selector.selectNow();
                    Iterator it;
                    synchronized(playersToRegisterToWrite) {
                        it = playersToRegisterToWrite.iterator();
                        while(it.hasNext()) {
                            Player player = (Player)it.next();
                            it.remove();
                            player.serverCon.configureBlocking(false);
                            player.serverCon.register(selector , SelectionKey.OP_WRITE , player);
                    Set keys = selector.selectedKeys() {
                    it = keys.iterator();
                    while(it.hasNext()) {
                        SelectionKey key = (SelectionKey)it.next();
                        if(key.isAcceptable()) {
                            it.remove();
                            clientCon = clientConSsc.accept();
                            clientCon.configureBlocking(false);
                            clientCon.register(selector , SelectionKey.OP_READ);
                            continue;
                        if(key.isReadable()) {
                            it.remove();
                            key.cancel();
                            new RequestHandler(this , (SocketChannel)key.channel()).start();
                            continue;
                        if(key.isWritable()) {
                            if(key.attachment() != null ) {
                                ServerAction action = null;
                                synchronized(actionsToDo) {
                                    Iterator aIt = actionsToDo.iterator();
                                    while(aIt.hasNext()) {
                                        ServerAction temp = (ServerAction)aIt.next();
                                        if(temp.getPlayer().equals((Player)key.attachment())) {
                                            action = temp;
                                            aIt.remove();
                                            break;
                                if(action != null) {
                                    key.channel().configureBlocking(false);
                                    it.remove();
                                    key.cancel();
                                    action.start();
                            continue;
                } catch(Exception e) {
                    statusArea.append(e.toString() + "\n");
                    e.printStackTrace();
                    continue;
        } catch(ClosedChannelException e) {
            statusArea.append(e.toString() + "\n");
        } catch(IOException e) {
            statusArea.append(e.toString() + "\n");
            A part of server's RequestHandler's class' method run() - the method which handles requests triggered by client on first port:
public void run() {
        boolean served = false;
            try {
                channel.configureBlocking(true);
                retryCount++;
                retry = false;
                String command = ns.readText(channel).trim();
                ns.statusArea.append("ktos przesyla komende: " + command + "\n");
                if(command != null && !command.equals("ERROR")) {
                    String[] cmd = command.split("�");
                    ns.statusArea.append("komenda: " + cmd[0] + "\n");
                    if(cmd[0].equals("CHAT")) {
                        if(cmd.length != 5) {
                            retry();
                        } else {
                            if(cmd[2].equals("NOGAME")) {      // jezeli nie ma okreslonej gry czyli rozsylamy do wszystkich
                                for(int i = 0 ; i < ns.loggedPlayersListItems.size() ; i++) {
                                    Player current = (Player)ns.loggedPlayersListItems.get(i);
                                    if(current.state == Player.CHOOSING && !current.equals(new Player(Integer.parseInt(cmd[1]))))   // jezeli gracz jest w okienku wybierania gry to wysylamy mu broadcast
                                        ns.actionsToDo.add(new SendMsg(ns , current , "CHAT�" + cmd[1] + "�" + cmd[3] + "�" + cmd[4]));
                            } else {
                                Game game = (Game)ns.gamesListItems.get(ns.gamesListItems.indexOf(new Game(Integer.parseInt(cmd[2]))));
                                for(int i = 0 ; i < game.players.size() ; i++) {
                                    Player current = (Player)game.players.get(i);
                                    if(!current.equals(new Player(Integer.parseInt(cmd[1]))))
                                        ns.actionsToDo.add(new SendMsg(ns , current , "CHAT�" + cmd[1] + "�" + cmd[3] + "�" + cmd[4]));
                            served = true;
                    } else if(cmd[0].equals("GETGAMEINFO")) {
                        if(cmd.length != 3)
                            retry();
                        else {
                            int gameID = Integer.parseInt(cmd[2]);
                            ns.statusArea.append("poproszono o informacje o grze nr: " + gameID + "\n");
                            Game checkedGame = new Game(gameID);
                            if(ns.gamesListItems.contains(checkedGame)) {
                                Game game = (Game)ns.gamesListItems.get(ns.gamesListItems.indexOf(checkedGame));
                                channel.configureBlocking(true);
                                ObjectOutputStream oos = new ObjectOutputStream(channel.socket().getOutputStream());
                                oos.writeObject(game);
                                oos.writeObject(game.players);
                                oos.flush();
                                ns.statusArea.append("wyslano informacje o grze nr: " + gameID + "\n");
                            } else {
                                ns.statusArea.append("brak gry o nr: " + gameID + "\n");
                            served = true;
            } catch(IOException e) {
                e.printStackTrace();
        if(!served) {
            ns.findAndDisconnectPlayer(channel);
        try {
            channel.close();
        } catch(IOException e) {
            e.printStackTrace();
    }An example of ServerAction's subclass - the class which triggers server commands to client on second port:
class UpdateLoggedPlayersList extends ServerAction {
    public UpdateLoggedPlayersList(NeuroServer ns , Player player) {
        super(ns , player);
    public void run() {
        try {
            serverCon.configureBlocking(true);
            ns.sendText("UPDATELOGGEDPLAYERSLIST" , serverCon);
            if(ns.readText(serverCon).equals("OK")) {
                ObjectOutputStream oos = new ObjectOutputStream(serverCon.socket().getOutputStream());
                oos.writeObject(ns.loggedPlayersListItems);
                oos.flush();
            synchronized(ns.playersToRegisterToWrite) {
                 ns.playersToRegisterToWrite.add(player);
        } catch(IOException e) {
            e.printStackTrace();
}A part of client's CmdHandler's class' method run() - the method which handles commands triggered by server:
public void run() {
    try {
        while(works) {
            String command = nc.readText(nc.serverCon);
            System.out.println("Server przesyla komende: " + command + "\n");
            String[] cmd = command.split("�");
            if(cmd[0] != null && !cmd[0].equals("ERROR")) {
                if(cmd[0].equals("CHAT")) {
                    if(nc.chooseGameDialog != null && nc.chooseGameDialog.isVisible()) {     // jezeli na wybieraniu gry
                        newChatEntry(cmd[2] , null , cmd[3] , nc.chooseGameDialog.chatPane);
                    } else if(nc.readyDialog != null && nc.readyDialog.isVisible()) { // jesli na przygotowywaniu
                        Player sender = (Player)nc.actGame.players.get(nc.actGame.players.indexOf(new Player(Integer.parseInt(cmd[1]))));
                        newChatEntry(cmd[2] , sender.fraction , cmd[3] , nc.readyDialog.chatPane);
                    } else if(nc.ng != null) {                   // jesli w grze
                        Player sender = (Player)nc.actGame.players.get(nc.actGame.players.indexOf(new Player(Integer.parseInt(cmd[1]))));
                        newChatEntry(cmd[2] , sender.fraction , cmd[3] , nc.ng.inGameChatPane);
                } else if(cmd[0].equals("UPDATELOGGEDPLAYERSLIST")) {
                    nc.sendText("OK" , nc.serverCon , false);
                    nc.serverCon.configureBlocking(true);
                    ObjectInputStream ois = new ObjectInputStream(nc.serverCon.socket().getInputStream());
                    DefaultListModel players = (DefaultListModel)ois.readObject();
                    nc.chooseGameDialog.updateLoggedPlayersList(players);
    } catch(IndexOutOfBoundsException e) {
        System.out.println(e);
    } catch(IOException e) {
        System.out.println(e);
    } catch(ClassNotFoundException e) {
        System.out.println(e);
}And two methods I used in codes above: sendText(String text , SocketChannel sc) and readText(SocketChannel sc) - they are my "utility" methods, which I use to send and receive Strings through specified SocketChannels.
boolean sendText(String text , SocketChannel sc) {
    ByteBuffer bbuf = ByteBuffer.allocate(BSIZE);
    boolean sendRetry;
    boolean sent = false;
    do {
        sendRetry = false;
        try {
            StringBuffer cmd = new StringBuffer();
            cmd.setLength(0);
            if(text.length()+4 < 100)
                cmd.append("0");
            if(text.length()+4 < 10)
                cmd.append("0");
            cmd.append(Integer.toString(text.length()+4) + "�");
            cmd.append(text);
            cmd.append("\n");
            bbuf = charset.encode(CharBuffer.wrap(cmd));
            sc.write(bbuf);
            bbuf.clear();
            int n = sc.read(bbuf);
            if(n == 1) {
                bbuf.flip();
                Byte re = bbuf.get();
                if(re == 1) {
                    sendRetry = true;
                } else {
                    sent = true;
        } catch(Exception e) {
            findAndDisconnectPlayer(sc);
            try {
                sc.close();
            } catch(IOException f) {
                f.printStackTrace();
            return false;
    } while(!sent && sendRetry);
    return true;
String readText(SocketChannel sc) {
    ByteBuffer bbuf = ByteBuffer.allocate(BSIZE);
    int readRetryCount = -1;
    boolean readRetry;
    do {
        readRetry = false;
        readRetryCount++;
        StringBuffer cmd = new StringBuffer();
        cmd.setLength(0);
        bbuf.clear();
        try {
            readLoop:
            while(true) {
                int n = sc.read(bbuf);
                if(n > 0) {
                    bbuf.flip();
                    CharBuffer cbuf = charset.decode(bbuf);
                    while(cbuf.hasRemaining()) {
                        char c = cbuf.get();
                        if(c == '\r' || c == '\n') break readLoop;
                        cmd.append(c);
                } else break;
            statusArea.append(Thread.currentThread().getId() + " readText() odczytuje: " + cmd.toString() + "\n");
            if(cmd.length() < 3 || Integer.parseInt(cmd.substring(0 , 3)) != cmd.length()) {
                sc.write(ByteBuffer.wrap(new byte[] {1}));
                readRetry = true;
            } else {
                sc.write(ByteBuffer.wrap(new byte[] {0}));    // length OK
                return cmd.toString().substring(4 , cmd.toString().length());
        } catch(Exception e) {
            findAndDisconnectPlayer(sc);
            try {
                sc.close();
            } catch(IOException f) {
                f.printStackTrace();
            return "ERROR";
    } while(readRetry && readRetryCount < 3);
    findAndDisconnectPlayer(sc);
    try {
        sc.close();
    } catch(IOException e) {
        e.printStackTrace();
    return "ERROR";
}Edited by: Kakalec on Jul 23, 2008 11:04 AM

You seem to be using a horrendous mixture of PrintWriters, BufferedReaders, ObjectOutputStreams, and no doubt ObjectInputStreams. You can't do that.
Some rules about this:
(a) Whenever you use a stream or reader or writer on a socket, you must allocate it once for the life of the socket, not every time you want to do an I/O.
There are many reasons for this including losing buffered data in the old stream and auto-closure of the socket on garbage-collection of the old stream.
(b) You can't mix stream types on the same socket. (i) If you're writing objects, use an ObjectOutputStream, you must read with an ObjectInputStream, and you can't read or write anything that isn't supported by the API of ObjectOutputStream. (ii) If you're writing lines, use a BufferedWriter and a BufferedReader at the other end. If you're writing characters, use a Writer and a Reader. (iii) If you're writing primitive data or UTF strings, use a DataOutputStream and a DataInputStream. (iv) If you're writing bytes, use DataOutputStream and a DataInputStream or an OutputStream and an InputStream. You can't mix (i), (ii), (iii), and (iv).
(c) Don't use PrintWriter or PrintStream over the network. They swallow exceptions that you need to know about. They are for writing to the console, or log files, where you don't really care about exceptions.
(d) Call flush() before reading.
(e) Always close the 'outermost' output stream or writer of a socket, never the input stream or the socket itself. Closing any of these closes the socket and therefore makes the other stream unusable, but only closing the output stream/writer will flush it.

What do i do if my ipod touch is stolen? Can i get a new one with no payment?

I need some help trying to figure this out please

Report the incident to law enforcement.
No, you can't get a new one for free because it's stolen.
If you have the Find My iPhone app installed and it's a 4th generation iPod touch, follow the instructions here.
http://www.apple.com/support/mobileme/
See: Find My iPhone

Java and C++ (JNI) Two Way communication

Hello folks,
I was hoping someone would know the answer to this fairly simple (?) question.
I have a C++ program that kicks off a Java GUI. As the C++ program proceeds, it updates the state of the Java GUI, and all is well.
What I was wondering is: is there some way for the GUI to communicate back with the C++ code? For example, if the user presses a button, indicating that they want to alter the action of the C++ code.
The only option I had come up with was the C++ code polling the Java GUI to see if one of its buttons has been pressed, but this strikes me as being somewhat inefficient.
Many thanks in advance,
Stephen

Hi Stephen,
you could create a Java class containing the callbacks your GUI wants to call and implement these callbacks as native C++ methods.
Hope that helps,
Tobias

Exchange of initial key for two way encrypted communication

Hello all,
I think the following question has to do with my lack of knowledge of cryptography and will be happy for any pointers you might provide.
I am trying to encrypt socket communication between client/server. I have decided to use AES from the SUNJCE. I don't want to store a static key on the client as that would pose a threat(decompilation). And I don't want to send the key to the client as that would defeat the whole purpose of encryting the communication (the key might get sniffed over the network).
I have a feeling there is a better way but since I am new to crytpography I am a bit lost. Can anybody tell me if there is a standard (best-practice) way of doing this.
Thanks in advance for your help.
depeupleur_

For anyone interested in AES for flash check this code
out:
http://www.codecta.com.br/rijndael.zip
Wow - that is impressive.
I now have a different problem, i can protect the data
being transmitted between server and a legitimate
client but since the connection is done through
internet and i don't know who the potential users are
how can i make sure the client that connects in the
first place is not a rogue client looking to replace a
proper client and trying to determine the
communication protocols and encryption mechanisms?You really do need to read up on how this stuff works. If "Applied Crypto" is too much, there's another book, "Practical Cryptography", by Ferguson and Schneier, that covers the topic pretty readably as well. (The first section, anyway - it gets pretty dense after that...)
In general - if you're going to worry about the identity of the client, you can set up your server to require client-side certificates. Explaining how certificates work is more than a forum-message thing.
Note that, in The Land of Crypto, you must assume that The Bad Guy knows everything about your communications protocols except for the key. If your security relies on hiding them, or your specific encryption algorithm, then you're pretty much toast.
Too right, i won't even pretend that i could write any
crypto code. (unless it is for my little son to
decrypt as a game)It's actually a very interesting field. I would not call myself a cryptographer by any stretch of the imagination - I'm just an educated user of crypto libraries. With a little research, you can be one too! ;)
Good luck,
Grant

SCTL-NFC1 is a Near Field Communication(NFC)/Radio Frequency Identification(RFID) Reader and Payment Adaptor designed for iPhone/iPod Touch to provide NFC two-way communication,RFID read/write and contactless payment capabilities.

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