Character recognition using java

Hi guys,
I have a fairly complex problem that I need to solve. Basically I am reading a set of pixel colours from a 3rd party client. I need to take this pixel data and recognize the characters used in it.
Does anybody know of any good character recognition tutorials I can use?
Anybody every done anything like this?
Any help will be great
Thanks
Alex

over the last month or so i have checked out those links and the downloadable software they offer, however, you can only us their trail versions which arent suitable for me.
Does anybody know where I should start if i want to write my own OCR functionality? are neural nets the best way to go?
Any advice/suggestions will be great.
Thanks
alex

Similar Messages

Unrecognised Char in GB2312 character set using java InputStreamReader??

Reading the following file chinese GB2312 html file from
http://news.xinhuanet.com/local/2007-02/13/content_5732705.htm
using the InputStreamReader with GB2312 encoding as shown below
public class readGB2312html file
//........TmpText declarations.....
public static void main( String[] args )
try
FileInputStream is = new FileInputStream( args[0] );
BufferedReader br = new BufferedReader(
new InputStreamReader( is, "GB2312" ) );
String strLine;
while ( (strLine = br.readLine()) != null )
TmpText.append(strLine);
TmpText.append("\r\n");
br.close();
bw.close();
catch ( Exception e )
e.printStackTrace();
The TmpText variable does not display the last character in the article properly （记者夏珺） it gives instead （记者夏?B）
Inside the html file the unrecognised charcter is represented by �B in the html file Why is this so
��B��
In the internet browser it is displayed and recognised as a chinese GB2312 character why not recognised by Java InputStreamReader???
Any help or explanation would be much appreciated

Yes, it is not a GB2312 character
The �B character is AC40 in hex format which is outside of the GB2312 character range, it is in GBK
Copied from wikipedia,
GBK is an extension of the GB2312 character set for simplified Chinese characters, used in the People's Republic of China.
GB stands for National Standard, while K stands for Extension. GBK not only extended the old standard GB2312 with Traditional Chinese characters, but also with Chinese characters that were simplified after the establishment of GB2312 in 1981. With the arrival of GBK, certain names with characters formerly unrepresentable, like the "rong" (�g) character in former Chinese Premier Zhu Rongji's name, are now representable.
Thanks a lot will use the GBK charset to read the file for all GB2312 file since it is a subset of it.

Speech recognition using java

*1*.>hi i am new to this area ..please help.this is relating speech to text ..the tutorial says...
Place this grammar into a file.
grammar javax.speech.demo;
public <sentence> = hello world | good morning |
hello mighty computer;
then the helloworld prg code
*where should i place this grammar...which file?
what is JSGF*
*2.*>is freetts only speech synthesizer(text to speech) ?
or can it be used fr speech to text also?
*+3.>*is cloudgarden sdk version fine fr speech to text...?

Try to look in JavaSpeech

Need help in how to print new line character in unix using java

Hi All,
I use the printstream class to print some line in a text using java.
here is the code:
   FileOutputStream out; // declare a file output object
        PrintStream p; // declare a print stream object
                p.print("\t");
                p.print(date);
                p.print("\t\t");
                p.print(RecCount);
                p.println("\n");when i use this and output of this character in windows is
date RecCount
22-07-2007 23456
when i use the same code in unix it shows the following output:
date RecCount[]22-07-2007
it wont accept the new line character could any one give me an idea to solve this problem.

PrintStream has a println() method. Use that. Or System.getProperty("line.separator").
Because a newline char doesn't necessarily specify a line break. It's system-dependent.

Character recognition results in question marks using CuteFTP

I'm have trouble with character recognition when I upload my site to Network Solutions using CuteFTP. Some returns, apostrophies, etc. appear as question marks. I have tried changing the prefernces to Macbinary and to binary without any change. Any suggestions?

For my own education...
Would my solution have worked?
I realize that it's not a true fix. It's a
workaround. However, I'd like to know if it would
have made a difference.
Yes, if you confine your text to pure ascii, without any "smart" punctuation, that may work. However, the templates often have other non-punctuation characters in them already that cause the same kind of problem and removing all of them could be really tedious.

How to train OCR using VISION ASSISTANT for multiple character recognition

Sir I have tried training OCR using Vision Assistant for character recognition. For the process i have used a fixed focus camera but the character i had trained were undetectable. So sir please provide me a liable solution to the problem.
Thank you.
I have attached my project description and also the .vi file of my work towards it.
Attachments:
Project phase I.vi ‏138 KB
WP_20140814_17_27_38_Pro.jpg ‏1444 KB

Can you post a real jpg instead of renaming a bmp to jpg?

How to extract the number from image using java

Hello every one
i want to develope a project which can extract the number from image
that i can use as inter or String or char.
Is there any API in java which provide this type of facility.
right now i m using java 5
thanks in Advance
Jignesh

In my project i have a image in that i have a
co-ordinate (x,y) I am still puzzled as to what you seek. It sounds to me like you have a point (x, y) represented by p. in java it's just p.getX() p.getY()
i want to convert that cordinate to numeric form,
i mena i want to use that cordinate in somewhere else
in project.point.getX() point.getY()
So need to convert it into numeric form u can called
it OCR also.OCR is optical character recognition. If I want out and took a picture of the US Declaration of Independence and then wanted the words on the parchement in the picture in text form, then I would run the picture through a software program and it would try to optically recognise what lettering and number were present in the picture. In the end, I would have a text of what is written on the US Declaration of Independence.
Is that what you want?

Debian Linux character recognition problem

Maybe this shouldn't be on this forum, but perhaps someone can help me...
I have Jrun 3.1, java 2 1.4 and Debian Linux.
On our test server everything was hunky dory, running perfectly.
But once everything was on the real server, we've had a character recognition problem. All of the higher characters are just replaced by a y or a ?.
I'm pretty sure that we can exclude java from the problem, the i18n.jar, which I believe holds all the international stuff is there and in the classpath (exactly as on the test server) and jrun is exactly as on the test server because we copied every folder as it was.
Therefore I think we can bring it down to Linux (Debian).
I cannot find where to look in Debian for any kind of keyboard or locale problem. Anyone know what to do?
kbdconfig command doesn't exist on our system.
Any help greatly appreciated.
We are in Italy, by the way.
Thanks.

If you check out the default file encoding you'll find that it's 7-bit ASCII; no characters > '\u007F' come out as they should. This applies as well to compiling as to running.
You can compile with another character encoding using the command line options, like: "javac -encoding ISO-8859-1 package/YourClass.java" (available at least in 1.4) and "java -Dfile.encoding=iso-8859-1 package.YourClass".

Character recognition

Hello!
I would like to make a class which will have to recognize the text from scanned technical drawings.
Using Google ( to find resources, technical information) I have found only OCR software for sale, while I am more interested in pages which will teach the way the recognition process is taking place ( if it has some example in Java will be better).
Can you give me some indication about how it can be done " character recognition"?
Thank you!

This should give you a nice evening of reading :
http://cgm.cs.mcgill.ca/~godfried/teaching/pr-web.html

Socket example using Java 5

Last year I posted 4 programs that provided a simple client server using both stream sockets and NIO. I decided as an exercise in using Java 5 to port that code and try to use as many of the new features as possible. The following code is very long and does what all the previous example programs did. In replies do not repost the whole of this message.
It provides a simple chat like client and server. The user can request either a stream connection or a NIO connection or provide one of their own.
//========================== MsgSwitch.java ===========================//
package pkwnet.msgswitch;
import java.util.logging.Logger;
import java.util.logging.Level;
import java.util.logging.Handler;
* main class for message switch
* command line arguments are
* -p port number for server
* -s run server
* -a server ip address including port for client
* -i idle timer in seconds
* -n use NIO
* -c specify connection class
public class MsgSwitch {
    static private int errors = 0;
    static private String address = "127.0.0.1:6060";
    static private String connectionClass = "pkwnet.msgswitch.StreamConnection";
    static public void main(String [] args) {
        int port = 6060;
        int idleTime = 600;
        boolean server = false;
        boolean nio = false;
        Logger logger = Logger.getLogger("msgswitch");
        for(String arg : args) {
            if(arg.startsWith("-a")) {
                address = arg.substring(2);
            } else if(arg.startsWith("-p")) {
                port = argToInt(arg);
                server = true;
            } else if(arg.startsWith("-i")) {
                idleTime = argToInt(arg);
            } else if (arg.startsWith("-s")) {
                server = true;
            } else if (arg.startsWith("-c")) {
                connectionClass = arg.substring(2);
            } else if (arg.startsWith("-n")) {
                connectionClass = "pkwnet.msgswitch.NIOConnection";
            } else {
                String err = "unknown argument=" + arg;
                logger.severe(err);
                System.err.println(err);
                errors++;
        if (errors == 0) {
            if (server) {
                new Server().listen(port,idleTime, nio);
            } else {
                new Client().start(address, nio);
        } else {
            fail(errors + " errors encountered", null);
    static private int argToInt(String arg) {
        int val = 0;
        try {
            val = Integer.parseInt(arg.substring(2));
        } catch (NumberFormatException e) {
            String err = "invalid argument format: " + arg;
            Logger.getLogger("msgswitch").severe(err);
            System.err.println(err);
            errors++;
        return val;
    static public void fail(String err, Throwable e) {
        String msg = "Operation terminated: " + err;
        Logger.getLogger("msgswitch").log(Level.SEVERE, msg, e);
        System.err.println(msg);
        System.exit(12);
    static public Connection getConnection() {
        Connection conn = null;
        try {
            conn = (Connection) Class.forName(connectionClass).newInstance();
        } catch (Exception e) {
            fail ("connection class error", e);
        return conn;
    static public void logCaller(Logger logger, Level level) {
        String text = "CALLED";
        if (logger.isLoggable(level)) {
            try {
                throw new Exception("logging stack");
            } catch (Exception e) {
                StackTraceElement [] st = e.getStackTrace();
                if (st.length > 1) {
                    text += formatElement(st[1]);
                if (st.length >2) {
                    text += formatElement(st[2]);
            logger.log(level, text);
    static private String formatElement(StackTraceElement ste) {
        return "\n    " + ste.getClassName() + "." + ste.getMethodName()
            + "(" + ste.getFileName() + ":" + ste.getLineNumber() + ")";
//================= Client.java =============================================//
package pkwnet.msgswitch;
* a simple Swing chat GUI using Java 5 and sockets.
* @author PKWooster
* @version 1.0 August 31,2005
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JTextArea;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JMenu;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JDialog;
import javax.swing.SwingUtilities;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.BorderLayout;
import static java.awt.BorderLayout.*;
client GUI class
public class Client extends JFrame implements ConnectionListener {
     // swing GUI components
     private JTextField userText = new JTextField(40);
     private JTextArea sessionLog = new JTextArea(24,40);
     private JTextField statusText = new JTextField(40);
     private JPanel outPanel = new JPanel();
     private JScrollPane sessionLogScroll = new JScrollPane(sessionLog);
     private JMenuBar menuBar = new JMenuBar();
     private JMenuItem startItem = new JMenuItem("Start");
     private JMenuItem hostItem = new JMenuItem("Host");
     private JMenuItem aboutItem = new JMenuItem("About");
     private JMenuItem abortItem = new JMenuItem("Abort");
     private JMenuItem exitItem = new JMenuItem("Exit");
     private JMenu fileMenu = new JMenu("File");
     private JMenu helpMenu = new JMenu("Help");
     private Container cp;
     private String address;
    private Connection connection;
    private boolean sendReady = false;
    private boolean nio = false;
     Client() {
    public void start(String address, boolean nio) {
        this.address = address;
        this.nio = nio;
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                runClient();
    private void runClient() {
        connection = MsgSwitch.getConnection();
        connection.addConnectionListener(this);
          buildMenu();
          cp = getContentPane();
          sessionLog.setEditable(false);
          outPanel.add(new JLabel("Send: "));
          outPanel.add(userText);
          // enter on userText causes transmit
          userText.addActionListener(new ActionListener(){
               public void actionPerformed(ActionEvent evt){userTyped(evt);}
          cp.setLayout(new BorderLayout());
          cp.add(outPanel,NORTH);
          cp.add(sessionLogScroll,CENTER);
          cp.add(statusText,SOUTH);
          setStatus("Closed");
          addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent evt) {
                mnuExit();
          pack();
        setVisible(true);
* attempt to send the contents of the user text field
    private void userTyped(ActionEvent evt) {
        if (sendReady) {
            String txt = evt.getActionCommand()+"\n";
            userText.setText("");
            toSessionLog("> ", txt);
            sendReady = false;
            connection.send(txt);
* append text to the session log
     private void toSessionLog(String prefix, String txt) {
          sessionLog.append(prefix + txt);
          sessionLog.setCaretPosition(sessionLog.getDocument().getLength() ); // force last line visible
* build the standard menu bar
     private void buildMenu()
          JMenuItem item;
          // file menu
          startItem.addActionListener(new ActionListener()
          {public void actionPerformed(ActionEvent e){mnuStart();}});
          fileMenu.add(startItem);
          hostItem.addActionListener(new ActionListener()
          {public void actionPerformed(ActionEvent e){mnuHost();}});
          fileMenu.add(hostItem);
          exitItem.addActionListener(new ActionListener()
          {public void actionPerformed(ActionEvent e){mnuExit();}});
          fileMenu.add(exitItem);
          menuBar.add(fileMenu);
          helpMenu.add(aboutItem);
          aboutItem.addActionListener(new ActionListener()
          {public void actionPerformed(ActionEvent e){mnuAbout();}});
          menuBar.add(helpMenu);
          setJMenuBar(menuBar);
* start and stop communications from start menu
     private void mnuStart() {
        if(connection.getState() == Connection.State.CLOSED) {
            connection.connect(address);
        } else {
            connection.disconnect();
* prompt user for host in form address:port
    private void mnuHost() {
          String txt = JOptionPane.showInputDialog("Enter host address:port", connection.getAddress());
          if (txt == null)return;
        address = txt;
     private void mnuAbout() {
          JDialog dialog = new JDialog(this, "About Client");
          JTextField text = new JTextField("Simple character client");
        dialog.getContentPane().add(text);
        dialog.pack();
        dialog.setVisible(true);
     // exit menu
     private void mnuExit() {
        exit();
    private void exit() {
          connection.disconnect();
          System.exit(0);
     private void setStatus(String st) {
        statusText.setText(st);
     private void setStatus(Connection.State state) {
        switch(state) {
            case OPENED:
                startItem.setText("Stop");
                setStatus("Connected to "+address);
                break;
            case CLOSED:
                startItem.setText("Start");
                setStatus("Disconnected");
                break;
            case OPENING:
                setStatus("Connecting to "+address);
                startItem.setText("Abort");
                break;
            case CLOSING:
                setStatus("Disconnecting from "+address);
                startItem.setText("Abort");
                break;
    public void stateChanged(final ConnectionEvent event) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                setStatus(event.getState());
    public void dataAvailable(final ConnectionEvent event) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                setStatus(event.getState());
                String txt = event.getData();
                if (txt == null) {
                    txt = "$null$";
                toSessionLog("< ", txt + "\n");
    public void sendAllowed(final ConnectionEvent event) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                setStatus(event.getState());
                sendReady = true;
    public void accept(ConnectionEvent event) {
//========================== Server.java ===============================//
package pkwnet.msgswitch;
import java.io.*;
import java.net.*;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
* a simple message switch using stream based socket i/o
* a very simple text message switching program
* user commands start with $ and consist of blank seperated arguments
* other lines sent by the user are forwarded
* $on nickname targets
*    sign on as nickname, sending to targets
* $to targets
*    change target list, reports current value
* $list nicknames
*    list status of specified nicknames
* $list
*    list all connected users
* $off
*    sign off
* @author PKWooster
* @version 1.0 September 1, 2005
public class Server {
    private ConcurrentHashMap<String, User> perUser = new ConcurrentHashMap<String,User>();
    private Timer idleTimer;
    private Connection conn;
    public void listen(int port, final int idleTime, boolean nio) {
        idleTimer = new Timer();
        idleTimer.scheduleAtFixedRate(new TimerTask(){public void run(){oneSec();}},0,1000);
        conn = MsgSwitch.getConnection();
        conn.addConnectionListener(new ConnectionListener() {
            public void stateChanged(ConnectionEvent event) {
            public void dataAvailable(ConnectionEvent event) {
            public void sendAllowed(ConnectionEvent event) {
            public void accept(ConnectionEvent event) {
                Connection uconn = event.getConnection();
                new User(uconn, perUser, idleTime);
        conn.listen(port);
        idleTimer.cancel();
    private void oneSec() {
        Collection<User> uc = perUser.values();
        for(User u : uc) {
            u.oneSec();
//================= User.java ==============================================//
package pkwnet.msgswitch;
import java.io.*;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Logger;
import java.util.logging.Level;
* defines the processing for a message switch user
* @author PKWooster
* @version 1.0 June 15,2004
public class User implements ConnectionListener {
    private ConcurrentHashMap<String, User> perUser;
    private String name;
    private String address;
    private boolean signedOn = false;
    private String[] targets;
    private AtomicInteger remainingTime;
    private int idleTime;
    Connection conn;
    Logger logger;
* construct a user, link it to its connection and put it in the perUser table
    User(Connection conn, ConcurrentHashMap<String,User>p, int idle) {
        this.conn = conn;
        logger = Logger.getLogger("msgswitch.user");
        conn.addConnectionListener(this);
        address = conn.getAddress();
        logger.info("creating user " + address);
        perUser = p;
        idleTime = idle;
        remainingTime = new AtomicInteger(idleTime);
        rename(address);
        targets = new String[0];
* process state changes
    public void stateChanged(ConnectionEvent event) {
        if(event.getState() == Connection.State.CLOSED) {
            close(false);
* data is available, process commands and forward other data.
    public void dataAvailable(ConnectionEvent event) {
        String msg = event.getData();
        if (msg.startsWith("$")) {
            doCommand(msg);
        } else {
            forward(msg);
        remainingTime.set(idleTime);
* do nothing for sendAllowed events
    public void sendAllowed(ConnectionEvent event) {
* do nothing for accept events
    public void accept(ConnectionEvent event) {
* called once per second by the server main thread.
    public void oneSec() {
        if(idleTime != 0 && 1 > remainingTime.decrementAndGet()) {
            close(true);
* send a message
    private void send(String msg) {
        conn.send(msg);
        remainingTime.set(idleTime);
* forward data messages to other users
* @param txt the message to send
    private void forward(String txt) {
        txt = name+": "+txt + "\n";
        if(0 < targets.length) {
            for(String target :targets) {
                User user = perUser.get(target);
                if(user != null) {
                    user.send(txt);
        } else {
            for (User user : perUser.values()) {
                if (user != this) {
                    user.send(txt);
* execute command messages, commands start with a $
* and contain arguments delimited by white space.
* @param command the command string
    private void doCommand(String command) {
        boolean good = false;
        command = command.substring(1).trim();
        if(command.length() > 0) {
            String [] args = command.split("\\s+");
            if(args[0].equals("on")) {
                good = signOn(args);
            } else if(args[0].equals("off")) {
                good = signOff(args);
            } else if(args[0].equals("list")) {
                good = listUsers(args);
            } else if(args[0].equals("to")) {
                good = setTargets(args,1);
            } else if(args[0].equals("idle")) {
                good = setIdle(args);
            if(!good) {
                send("invalid command=" + command + "\n");
* sign on command
    private boolean signOn(String [] args) {
        boolean good = false;
        if(args.length >1) {
            String nm = args[1];
            logger.info("signing on as: " + nm);
            if(rename(nm)) {
                conn.setName(name);
                send("Signed on as " + name + "\n");
                signedOn = true;
                good = true;
                setTargets(args,2);
            } else {
                send("name="+nm+" already signed on\n");
        return good;
* set forwarding targets
    private boolean setTargets(String [] args, int start) {
        if(start < args.length) {
            targets = new String[args.length-start];
            System.arraycopy(args, start, targets, 0, targets.length);
        String str = "to=";
        for(String target : targets) {
            str += (target + " ");
        send(str+"\n");
        return true;
* set idle timeout
    private boolean setIdle(String[] args) {
        try {
            idleTime = new Integer(args[1]).intValue();
            remainingTime.set(idleTime);
            send("idle time set to "+idleTime+"\r\n");
            return true;
        } catch(NumberFormatException exc) {
            return false;
* sign off
    private boolean signOff(String [] args) {
        close(true);
        return true;
* list connected users
    private boolean listUsers(String [] args) {
        TreeSet<String> allUsers = new TreeSet<String>(perUser.keySet());
        HashSet<String> t = new HashSet<String>(Arrays.asList(targets));
        LinkedList<String> users;
        String response = "On,Target,Nickname\n";
        if(args.length < 2) {
            users = new LinkedList<String>(allUsers);
        } else {
            users = new LinkedList<String>();
            for (int i = 1; i < args.length; i++) {
                users.add(args);
for(String username : users) {
if(username.equals(name)) {
response += "*,";
} else {
response += (allUsers.contains(username) ? "y," : "n,");
response += (t.contains(username) ? "y," : "n,");
response += (username + "\n");
send(response);
return true;
* rename this user, first we attempt to add the new name then we remove
* the old one. Both names will be registered for a short while.
* @param newname the new name for this user
* @return true if the rename was successful
private boolean rename(String newname) {
boolean b = false;
logger.info("rename name="+name+" newname="+newname);
if (name != null && name.equals(newname)) {
b = true;
} else if (null == perUser.putIfAbsent(newname, this)) {
if (name != null) {
perUser.remove(name);
name = newname;
b = true;
return b;
* delete from perUser and close our connection
private void close(boolean disconnect) {
logger.info("closing user "+name);
perUser.remove(name);
if (disconnect) {
conn.disconnect();
//====================== Connection.java ===============================//
package pkwnet.msgswitch;
import java.util.HashSet;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.logging.Logger;
import java.util.logging.Level;
public abstract class Connection {
public enum State {CLOSED, OPENING, OPENED, CLOSING}
private HashSet<ConnectionListener> listeners = new HashSet<ConnectionListener>();
private State state = State.CLOSED;
private String host = "127.0.0.1";
private int port = 6060;
private String name = "unconnected";
public Connection() {
public abstract void listen(int port);
public abstract void connect(String address);
public abstract void disconnect();
public abstract void send(String message);
public void addConnectionListener(ConnectionListener listener) {
listeners.add(listener);
public void removeConnectionListener(ConnectionListener listener) {
listeners.remove(listener);
protected void fireDataAvailable(String data) {
for (ConnectionListener listener : listeners) {
listener.dataAvailable(new ConnectionEvent(this, state, data));
private void fireStateChanged() {
for (ConnectionListener listener : listeners) {
listener.stateChanged(new ConnectionEvent(this, state));
protected void fireSendAllowed() {
for (ConnectionListener listener : listeners) {
listener.sendAllowed(new ConnectionEvent(this, state));
protected void fireAccept(Connection conn) {
for (ConnectionListener listener : listeners) {
listener.accept(new ConnectionEvent(this, conn));
protected void setState(State state) {
if (this.state != state) {
this.state = state;
fireStateChanged();
public State getState() {
return state;
protected void setAddress(String address) {
          int n = address.indexOf(':');
          String pt = null;
setName(address);
if(n == 0) {
               host = "127.0.0.1";
               pt = address.substring(1);
          else if(n < 0) {
               host = address;
               port = 5050;
          } else {
host = address.substring(0,n);
               pt = address.substring(n+1);
if (pt != null) {
try {
port = Integer.parseInt(pt);
} catch (NumberFormatException e) {
port = -1;
public String getName() {
return name;
public void setName(String value) {
name = value;
public String getAddress() {
return host + ":" + port;
public String getHost() {
return host;
public void setPort(int value) {
port = value;
public int getPort() {
return port;
//=================== ConnectionEvent.java ================================//
package pkwnet.msgswitch;
public class ConnectionEvent extends java.util.EventObject {
private final String data;
private final Connection.State state;
private final Connection conn;
public ConnectionEvent(Object source, Connection.State state, String data, Connection conn) {
super(source);
this.state = state;
this.data = data;
this.conn = conn;
public ConnectionEvent(Object source, Connection.State state, String data) {
this(source, state, data, null);
public ConnectionEvent(Object source, Connection.State state) {
this(source, state, null, null);
public ConnectionEvent(Object source, Connection conn) {
this(source, conn.getState(), null, conn);
public Connection.State getState() {
return state;
public String getData() {
return data;
public Connection getConnection() {
return conn;
//============================ ConnectionListener.java ===================//
package pkwnet.msgswitch;
public interface ConnectionListener extends java.util.EventListener {
public void stateChanged(ConnectionEvent event);
public void dataAvailable(ConnectionEvent event);
public void sendAllowed(ConnectionEvent event);
public void accept(ConnectionEvent event);
//============================ StreamConnection.java ===================//
package pkwnet.msgswitch;
import java.net.Socket;
import java.net.ServerSocket;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.IOException;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.logging.Logger;
import java.util.logging.Level;
* provides stream socket i/o of character strings
* @author PKWooster
* @version 1.0 September 1, 2005
public class StreamConnection extends Connection {
private Socket sock;
private BufferedReader in;
private BufferedWriter out;
private Thread recvThread = null;
private Thread sendThread = null;
protected LinkedBlockingQueue<String> sendQ;
Logger logger;
public StreamConnection() {
super();
logger = Logger.getLogger("msgswitch.stream");
sendQ = new LinkedBlockingQueue<String>();
* open a socket and start i/o threads
public void connect(String ipAddress) {
setAddress(ipAddress);
try {
sock = new Socket(getHost(), getPort());
connect(sock);
} catch (IOException e) {
logger.log(Level.SEVERE, "Connection failed to=" + ipAddress, e);
private void connect(Socket sock) {
this.sock = sock;
String ipAddress = getAddress();
try {
in = new BufferedReader(new InputStreamReader(sock.getInputStream()));
out = new BufferedWriter(new OutputStreamWriter(sock.getOutputStream()));
recvThread = new Thread(new Runnable() {
public void run() {
doRecv();
},"Recv." + getName());
sendThread = new Thread(new Runnable() {
public void run() {
doSend();
},"Send."+getName());
sendThread.start();
recvThread.start();
setState(State.OPENED);
} catch(IOException e) {
logger.log(Level.SEVERE, "Connection failed to="+ipAddress, e);
public void listen(int port) {
StreamConnection sconn;
setPort(port);
try {
ServerSocket ss = new ServerSocket(port);
while(true) {
Socket us = ss.accept();
sconn = new StreamConnection();
String ipAddress = us.getInetAddress() + ":" + us.getPort();
sconn.setAddress(ipAddress);
sconn.connect(us);
fireAccept(sconn);
} catch(Exception e) {
logger.log(Level.SEVERE, "listen failed", e);
* close the socket connection
public void disconnect() {
logger.fine("disconnect sock=" + sock + " state="+ getState());
if(getState() == State.OPENED) {
setState(State.CLOSING);
try {
sock.shutdownOutput();
} catch(IOException ie) {
logger.log(Level.SEVERE, "showdown failed", ie);
} else if(getState() != State.CLOSED) {
try {
sock.close();
} catch(Exception e) {
logger.log(Level.SEVERE, "close failed", e);
if (sendThread.isAlive()) {
sendThread.interrupt();
sendQ.clear();
setState(State.CLOSED);
public void send(String message) {
if (getState() == State.OPENED) {
try {
sendQ.put(message);
} catch(InterruptedException e) {
logger.log(Level.SEVERE, "sendQ put interrupted", e);
setState(State.CLOSING);
disconnect();
* sets the public name of this connection
public void setName(String name) {
super.setName(name);
if (sendThread != null) {
try {
recvThread.setName("recv." + name);
sendThread.setName("send." + name);
} catch(Exception e) {
logger.log(Level.SEVERE, "nameing threads failed", e);
* the main loop for the send thread
private void doSend() {
String msg;
boolean running = true;
while (running) {
if (sendQ.size() == 0) {
fireSendAllowed();
try {
msg = sendQ.take();
out.write(msg);
out.flush();
} catch(Exception e) {
if (getState() == State.OPENED) {
logger.log(Level.SEVERE, "write failed", e);
setState(State.CLOSING);
disconnect();
running = false;
* the main loop for the receive thread
private void doRecv() {
String inbuf;
while (getState() == State.OPENED) {
try {
inbuf = in.readLine();
} catch(Exception e) {
if (getState() == State.OPENED) {
logger.log(Level.SEVERE, "readline failed", e);
inbuf = null;
if(inbuf == null) {
logger.fine("null received on: " + getAdd

Here are three of them:
NIO server
NIO client
Multithreaded server
The stream based client example seems to have been deleted, probably lost in the troll wars. I also posted a new Simple multithreaded server that uses the same protocol. As the client is missing, I'll repost it.

Running unix command using java shows error

Hi All,
I am trying to run UNIX move command using Java exec method but its throwing error, unable to rename. Here below is the code i am trying to run to move all files from one directory to another directory. source and destination directory exists.
public class Demo
    public static void main(String args[])
        try
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec("mv /home/demo1/* /home/demo2");
            int exitVal = proc.waitFor();
            System.out.println("Process exitValue: " + exitVal);
        } catch (Throwable t)
            t.printStackTrace();
}if i give "mv /home/demo1 /home/demo2" in exec method, its working, with * character its giving problem.
Please help me in resolving the problem.
Thank you

Characters like *, >, &, |, etc. are interpreted by the command shell--that is by the bash, zsh, etc. programs. When you execute a command with ProcessBuilder or Runtime.exec, you're not going through one of those shells, so their interpretation of those characters is not available.
In your code, the character * is being delivered directly to the mv command (which doesn't think * is anything special), as opposed to being turned into a list of files and directories as it would be when it's interpreted by the shell. The mv command doesn't know anything about the * character being special.
If you want to have those shell interpretations, you need to execute the command through a shell. One example is like so, but a) you'll want to read up on the methods in exec() that take arrays of String, and b) you'll want to read up on ProcessBuilder, and c) you'll need to check your shell's man pages to see the exact syntax and arguments.
runtime.exec("/bin/bash -c 'mv x/* y'");

Dynamic Programming Using Java

hiiii...anyone knows how to use a dynamic programming to compare a mouse movement using java??? i hope some one can help me......

This was just an idea. I do not know of any program
implementing this. I will not help you store coordinates
into a database, but I can explain my suggestion in
more detail.
Since the characters might be more dependent on the page
then the user, you must make a sub character for each page.
Your table row must then contain following fields:
user, time, page, x-cord, and y-cord.
Now assume following
- we will use the characters 'average speed' and
'centre of gravity of movement'.
- we have two sessions of data, that is two sets of table
rows as described above. Every set belongs to different
users.
- the sessions are spread on a set of pages.
Now we will compute the distance between these users. There
are a lot of distance metrics but let us choose the most
common one. Let P be a set of points in R^n and p.n
be the n coordinate of the point p in P. Then for any p1
and p2 in P, define the distance metric to be
D(p1,p2) = summa_{over n} (p1.n-p2.n)^2
Define the average speed for a certain user and page to be
Speed(user, page) (in) R. Further more let
Gravity(user, page) (in) R^2 be the centre of gravity of
movement for a user and page.
Then the total distance is
D(user_1, user_2) = summa_{over all pages} k1*D(Gravity(user_1, page), Gravity(user_2, page)) + k2*D(Speed(user_1, page), Speed(user_2, page))
where k1 and k2 are constants determines the importance
you want to assign the two characters.

Code for reading the and placing the file using java webservice

Hi All,
Can anybody can guide me on how to read a file and place the file using java.
Let me know if any code is available which has been completed using java.
Regards,
Rahul

Hi,
The "square" symbol that you are referring to is probably a CRLF (Carriage Return - Life Feed) Control Character.
This is more commonly known as a "Enter" at the end of a line / sentence.
To clean this character from strings in Java, please use:
String patternStr = "(?m)$^|[\\r\\n]+\\z";
String replaceStr = " ";
Pattern pattern = Pattern.compile(patternStr);
Matcher matcher = pattern.matcher(inputStr);
return matcher.replaceAll(replaceStr);
Hope that helps.
Thanks.
p256960.

OCR (Optical Character Recognition)

I have just bought this new printer/scanner.I am trying to use the OCR (Optical Character Recognition) text converter that came with my old printer. When I scan as a photo the output comes as several pictures and all the text is missing. When I scan as a document the output is in PDF. And the OmniPage text converter is of no use.Does anyone have any suggestion. Or should I just buy a new ink cartridge for my old Canon, and return this HP to Costco?Many thanks.

Your answer is much appreciated. I'll get round to trying the solution when I can whip up enough enthusiam. Right now I'm a bit fed up with trying to get the machine sorted out! Probably not so much the machine as the operator, it's way too hot here today. 33 deg celcius.I am a bit unsure if it will do the trick, but it's the best aswer so far!Thank you

Optical character recognition--how do I scan a document to text I can edit.

Optical character recognition--how do I scan a document to text I can edit?

You first scan the document to a PDF. Then you run OCR from within Acrobat. Depending on your setup, the OCR may be run automatically.
If you want to edit so the changes show on the screen, you will need to use ClearScan. The other two searchable options put the OCR text in a layer behind the image of your original document.

Character recognition using java

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