Java WD and Socket Communication

Hi,
Is it possible to use Java Socket Communication with Java Web Dynpro. Or if not what is the best approach to have a Java Socket program integrated with a Web Dynpro Communication.
Basically, I have an application which provides API for communication via Java Sockets.And this needs to be integrated in our SAP application.
Thanks,
CD

Hi,
You are currently using JCO to "Connect to a Remote System" - JCO will connect to a back-end with the main purpose of "executing BAPI's" in it.
When you move to WebDynpro, you have what SAP calls Adaptive RFC Model - this will create a "Model Entity" in you WD Project that will do the same thing your JCO does.
Assume your JCO now calls "BAPI_GET_FLIGHTS", to return the Flights that are currently available - In your newly create WDP Project, you will manually specify what back-end you wanna use when "Importing" and you will tell also the BAPI name. WDP will generate the class structure that you need in order to execute that function.
JCO is what SAP created to execute BAPI's. JCO can be used by any "Java" like application that needs to connect to the back-end. But when you move to WDP, you don't need to use this anymore - You will use WDP Models.
Youi will still need your JCO Destinations created in the Application Server, so behind the scenes WDP creates a "layer" so you don't need to code the JCO calls manually.
Regards,
Daniel

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a very simple C++ test applications the communictions work fine. Once more code gets added to the C++ application the portion of the socket that C++ listens to seems to close.
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a recv call the return value is a zero. Microsoft insists this is a sign the Java side has shut down the socket.
A correct implementation of recv should return the number of bytes received, or -1 for an error. A zero return indicates no bytes received not a socket closed/error. This sounds like FUD to me.
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I read some thread in the forum, and found somebody had the similar problem with me. Just want to know how to settle this problem.
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In the Client, using:
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outputToServer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
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hi
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Hi all,
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cheers
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P.S.
The server socket java application has two threads:
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I do not have the experience to offer advice. But I just happened to be reading today about Collections.synchronizedList.
import java.util.List;
import java.util.LinkedList;
import java.util.Collections;
public class Queue {
   private List queue;
   public Queue() {
      queue = Collections.synchronizedList(new LinkedList());
   public Object removeItem() throws InterruptedException {
      synchronized (queue) {
         while (queue.isEmpty())
            queue.wait();
         return queue.remove(0);
   public void addItem(Object item) {
      synchronized (queue) {
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class Test {
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      Runnable work = new Runnable() {
         public void run() {
            try {
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               //do something with item
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      worker.start();
}Reference: Java Thread Programming, Paule Hyde
Also, here is Doug Lea's library,
http://gee.cs.oswego.edu/dl/classes/EDU/oswego/cs/dl/util/concurrent/intro.html

Problem with socket communications

I am trying to put together a client server socket communication pair.
I have one application that runs in the background acting as a server and another that can be started and stopped that acts as a client.
I can start the server and create a server socket with no problem.
I can start the client and it connects to the server.
The server acknowledges the connection and appears to go into a blocking state waiting for the client to send another message.
The server blocks at the line
parent.logit("Waiting for message from EVR..... ");
The problem is that when the client sends another message, the server doesn't hear it.
I am not sure if the problem is with the client or server communication code.
If anyone out there is a socket communication guru, I would appreciate it if you could tell me what I am doing wrong.
Thanks
Server code:
import java.io.*;
import java.net.*;
public class EVRServer
    extends Thread
EVRDataLoader parent = null;
ServerSocket serverSock = null;
Socket clientSock = null;
BufferedReader reader = null;
BufferedWriter writer = null;
int evrPort = 0;
int retryLimit = 10;
int retryCount = 0;
boolean alive = false;
boolean killSocket = false;
boolean evrConnected = false;
boolean retry = true;
EVRListener evrListener = null;
//=============================================================================
// Full constructor
//=============================================================================
   * Full constructor.
   * @param dl DataLoader - Parent application
   * @param port int Socket port
public EVRServer(EVRDataLoader dl, int port)
    parent = dl;
    evrPort = port;
//=============================================================================
// Run method - Main thread executed by start() method
//=============================================================================
   * Main thread executed by start() method
public void run()
    while (retry)
      if (retryCount > retryLimit)
        retry = false;
      parent.logit("Retry count = " + retryCount);
      // Create new server socket connection
      if (serverSock == null)
        try
          serverSock = new ServerSocket(evrPort);
          parent.logit("Created Server Socket for EVR on port " + evrPort);
          alive = true;
          killSocket = false;
          evrConnected = false;
        catch (Exception e)
          parent.logit(
              "ERROR - Could not create Server socket connection for EVR: " +
              e.toString());
          killSocket = true;
          alive = false;
      // Create new client socket connection
      if (clientSock == null)
        try
          parent.logit("Waiting for EVR to connect");
          clientSock = null;
          clientSock = serverSock.accept();
          retryCount = 0;
          evrConnected = true;
          killSocket = false;
          parent.logit("EVR connected on server Socket Port " + evrPort);
        catch (Exception e)
          parent.logit("ERROR - Error accepting EVR connection: " + e.toString());
          killSocket = true;
        try
          reader = new BufferedReader(new InputStreamReader(
              clientSock.getInputStream()));
          writer = new BufferedWriter(new OutputStreamWriter(
              clientSock.getOutputStream()));
          parent.logit( "Created reader "+reader);
          parent.logit( "Created writer "+writer);
        catch (Exception e)
          parent.logit(
              "ERROR - creating reader or writer to EVR: " + e.toString());
          killSocket = true;
      int nullCount = 0;
      while (killSocket == false)
        try
          parent.logit("Waiting for message from EVR..... ");
//          sendMessage("Data Controller connected on port " + evrPort);
          String s = reader.readLine();
          parent.logit("EVR - Received message: " + s);
          if (s != null)
            parent.processEvrMessage( s);
          else
            sleep(1000);
            nullCount++;
            if (nullCount > 10)
              parent.logit("Exceeded retry limit: ");
              killSocket = true;
        catch (Exception ex)
          parent.logit("Error Reading from EVR: " + ex.toString());
          killSocket = true;
      parent.logit( "After while loop");
      evrConnected = false;
      try
        retryCount++;
        parent.logit("Closing EVR connection. ");
        reader.close();
        writer.close();
        clientSock.close();
        writer = null;
        reader = null;
        clientSock = null;
        try
          sleep(1000);
        catch (Exception ee)
          parent.logit("Error after sleep " + ee.toString());
      catch (Exception e)
        parent.logit("Error closing EVR server socket");
//=============================================================================
// Call this method to kill the client socket connection.
//=============================================================================
   * Call this method to kill the client socket connection.
public void killConnection()
    killSocket = true;
//=============================================================================
// Return RTM connected state
//=============================================================================
   * Return RTM connected state
   * @return boolean - Returns true if RTM is connected to server, false if not.
public boolean isRtmConnected()
    return evrConnected;
//=============================================================================
// Returns state of server socket.
//=============================================================================
   * Returns state of server socket.
   * @return boolean - Returns true if server socket is enabled, false if not.
public boolean isServerSocketAlive()
    return alive;
//=============================================================================
// Send a message to the client socket.
//=============================================================================
     * Send a message to the client socket.
     * @param msg String - Message to send.
     * @return boolean - Returns true if message sent OK, false if not.
public boolean sendMessage(String msg)
    parent.logit(" In EVR Server - Send Message - got message: " + msg);
    if (evrConnected)
      try
        parent.logit("Sending message to EVR: " + msg);
        writer.write(msg + "\n");
        writer.flush();
        return true;
      catch (Exception e)
        parent.logit("ERROR - Error sending message to EVR: " + e.toString());
        return false;
    else
      parent.logit("EVR not connected, cannot send message: " + msg);
      return false;
}Client code:
package evrsimulator;
import java.net.*;
import java.io.*;
class PortConnector
      extends Thread
   ServerSocket serverSock = null;
   boolean isIP = false;
   InetAddress addr = null;
   Frame1 parent = null;
   byte[] rawIP;
    //   String initialMsg = "";
   public PortConnector( Frame1 f )
     parent = f;
   // This method is called when the thread runs
   public void run()
      if ( parent.hostName.indexOf( "." ) > 0 )
         isIP = true;
         byte[] rawIP = parent.getRawIP( parent.hostName );
      try
         System.out.println( "Connecting to host " +
                                        parent.hostName + " on port " +
                                        parent.socketPort );
         if ( isIP )
            addr = InetAddress.getByAddress( rawIP );
         else
            addr = InetAddress.getByName( parent.hostName );
         System.out.println( "Inet address = " + addr );
         SocketAddress sockaddr =
               new InetSocketAddress( addr, parent.socketPort );
         // Create an unbound socket
         parent.client = new Socket();
         // This method will block no more than timeoutMs.
         // If the timeout occurs, SocketTimeoutException is thrown.
         parent.client.connect( sockaddr, parent.socketTimeOut );
         parent.socketOut =
               new BufferedWriter( new OutputStreamWriter(
               parent.client.getOutputStream() ) );
         parent.socketIn = new BufferedReader( new InputStreamReader(
               parent.client.getInputStream() ) );
         parent.localName = parent.localName +
               parent.client;
         System.out.println( "Parent socketOut = "+parent.socketOut);
         System.out.println( "Parent socketIn = "+parent.socketIn);
      catch ( UnknownHostException uhe )
         System.out.println( "Unknown Host - " + uhe.getMessage() );
      catch ( SocketTimeoutException ste )
         System.out.println( "Socket time out - " + ste.getMessage());
      catch ( IOException ioe )
         System.out.println( "IO exception - " + ioe.getMessage() );
      // Listen on socket for message from host - thread should block.
      parent.portConnected = true;
      while ( parent.portConnected )
         try
            String msg = parent.socketIn.readLine();
            System.out.println( "Message from Host: " + msg );
            System.out.println( "Message from Host: |" + msg + "|" );
            if( msg.length() > 2)parent.processMessage( msg );
         catch ( IOException ioe )
            System.out.println( "Exception creating server socket." );
      try
         System.out.println(
               "PortConnection - Closing socket and IO connections" );
         parent.socketIn.close();
         parent.socketOut.close();
         parent.client.close();
         parent.clockRunning = false;
         if( parent.heartBeating) heartBeat.interrupt();
      catch ( IOException ioex )
         System.out.println( "Exception closing socket." );
}

Your first problem is that you keep closing and recreating the ServerSocket. Do this once only in the lifetime of the server.
This is such a basic error that I haven't read the rest of the code. Before you go any further I suggest you read the Custom Networking trail of the Java Tutorial.

Socket communication problem

hello all,
i have written a small program to send a message to echo server and get back the response from the server.
it gives a error as
COULD NOT GET I/O FOR CONNECTION TO <ip address>
i am working on win nt version 4 service pack 4 installed on a home computer.
the code is as below:
import java.io.*;
import java.net.*;
public class net4a {
public static void main(String[] args) throws IOException{
Socket echoSocket = null;
DataOutputStream os = null;
DataInputStream is = null;
 DataInputStream stdIn = new DataInputStream(System.in);
 InetAddress host = InetAddress.getLocalHost();
try {
echoSocket = new Socket(host, 7);
os = new DataOutputStream(echoSocket.getOutputStream());
is = new DataInputStream(echoSocket.getInputStream());
} catch (UnknownHostException e) {
System.err.println("Don't know about host: " + host);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to: " + host);
if (echoSocket != null && os != null && is != null) {
try {
String userInput;
while ((userInput = stdIn.readLine()) != null) {
os.writeBytes(userInput);
os.writeByte('\n');
System.out.println("echo: " + is.readLine());
os.close();
is.close();
echoSocket.close();
} catch (IOException e) {
System.err.println("I/O failed on the connection to: " + host);
look forward to ur valuable tips on the same.

Hello,
Long time java programmer, first time forum user.
Looks like you looking to looking to get a java applet/program communicating with a web server. This is not an extremely difficult task and I have successfully got apache communicating CGI transactions to and from an applet with no drama�s.
This is very useful as it is restrictive to have to open up extra sockets across a network as many networks today restrict socket communication often for security or business/organization policies.
An alternative is to use HTTP request using the POST command to talk to a web server with the web server replying to the request. For example, you may need to ask a database to pull out all customer names from a server-side database. The applet need only send a URLEncoded request to the server, the webserver invokes the CGI process (I use Java to handle the CGI requests but other methods/languages can be used) which returns the result of the transaction.
I have listed some code that included the a �ping-pong� request to a server. It included the applet function that calls the webserver, the CGI batch script (for win NT/XP) to invoke the java program, the cgi-lib to simply parse the URL request (many thanks to the author) and the server-side java program that responds to the request.
I hope you find this useful. The download for apache, the webserver, is available at
http://www.apache.org/
and is a pretty simple install. Make sure you fix up the httpd.conf file to suit your system.
Good luck.
Dale Miller
CLIENT-SIDE (Java Applet Snippit)
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 private String server;
 private URL toServer;
 private URLConnection uRLConnection;
 private DataOutputStream dataOutputStream;
 private StringBuffer output;
 private BufferedReader dataInputStream;
 private String result;
 private int resultsLast;
 private String results[] = new String[100];
 private int firstTU;
 //this function starts in its own thread and takes care
 //of logins and there re-tries, the messaging.
 //Please see the actual function for better details
 //private LoginWatcher loginWatcher;
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 System.out.println("loaded Comm class!");
 //First thing we need to do is set up the login watcher
 //loginWatcher = new LoginWatcher();
 this.output = new StringBuffer();
 this.server = serverAddress;
 try {
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 } catch (MalformedURLException e) {
 System.out.println("ERROR : in contacting the server");
 System.out.println("Server : " + server);
 System.out.println("NOT FOUND!!");
 try {
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 } catch (IOException e) {
 System.out.println("ERROR : Connection to server refused");
 this.uRLConnection.setUseCaches(false);
 this.uRLConnection.setDoInput(true);
 this.uRLConnection.setDoOutput(true);
 this.uRLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
 try {
 this.dataOutputStream = new DataOutputStream(uRLConnection.getOutputStream());
 } catch (IOException e) {
 System.out.println("ERROR : opening dataoutputstream");
 this.output.setLength(0);
 output.append("first=" + URLEncoder.encode("I am", "UTF-8"));
 output.append("&last=" + URLEncoder.encode("number 1", "UTF-8"));
 try {
 dataOutputStream.writeBytes(new String(output));
 } catch (IOException e) {
 System.out.println("ERROR : Sending string to cgi ping.cgi");
 try {
 this.dataInputStream = new BufferedReader(new InputStreamReader(uRLConnection.getInputStream()));
 } catch (IOException e) {
 System.out.println("ERROR : Setting up input stream");
 String grab = new String();
 System.out.print("Searching for server..");
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import java.util.*;
import java.io.*;
* cgi_lib.java
* 
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* variables must be passed from the script into the Java application
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* CGI script:
* <pre>
* (testcgi.sh)
* #!/bin/sh
* java \
* -Dcgi.content_type=$CONTENT_TYPE \
* -Dcgi.content_length=$CONTENT_LENGTH \
* -Dcgi.request_method=$REQUEST_METHOD \
* -Dcgi.query_string=$QUERY_STRING \
* -Dcgi.server_name=$SERVER_NAME \
* -Dcgi.server_port=$SERVER_PORT \
* -Dcgi.script_name=$SCRIPT_NAME \
* -Dcgi.path_info=$PATH_INFO \
* cgi_lib
* </pre>
* Question and comments can be sent to [email protected].
* @version 1.0
* @author Pat L. Durante
class cgi_lib
* Parse the form data passed from the browser into
* a Hashtable. The names of the input fields on the HTML form will
* be used as the keys to the Hashtable returned. If you have a form
* that contains an input field such as this,
* <pre>
* &ltINPUT SIZE=40 TYPE="text" NAME="email" VALUE="[email protected]"&gt
* </pre>
* then after calling this method like this,
* <pre>
* Hashtable form_data = cgi_lib.ReadParse(System.in);
* </pre>
* you can access that email field as follows:
* <pre>
* String email_addr = (String)form_data.get("email");
* </pre>
* @param inStream The input stream from which the form data can be read.
* (Only used if the form data was posted using the POST method. Usually,
* you will want to simply pass in System.in for this parameter.)
* @return The form data is parsed and returned in a Hashtable
* in which the keys represent the names of the input fields.
public static Hashtable ReadParse(InputStream inStream)
Hashtable form_data = new Hashtable();
String inBuffer = "";
if (MethGet())
inBuffer = System.getProperty("cgi.query_string");
else
// TODO: I should probably use the cgi.content_length property when
// reading the input stream and read only that number of
// bytes. The code below does not use the content length
// passed in through the CGI API.
DataInput d = new DataInputStream(inStream);
String line;
try
while((line = d.readLine()) != null)
inBuffer = inBuffer + line;
catch (IOException ignored) { }
// Split the name value pairs at the ampersand (&)
StringTokenizer pair_tokenizer = new StringTokenizer(inBuffer,"&");
while (pair_tokenizer.hasMoreTokens())
String pair = urlDecode(pair_tokenizer.nextToken());
// Split into key and value
StringTokenizer keyval_tokenizer = new StringTokenizer(pair,"=");
String key = new String();
String value = new String();
if (keyval_tokenizer.hasMoreTokens())
key = keyval_tokenizer.nextToken();
else ; // ERROR - shouldn't ever occur
if (keyval_tokenizer.hasMoreTokens())
value = keyval_tokenizer.nextToken();
else ; // ERROR - shouldn't ever occur
// Add key and associated value into the form_data Hashtable
form_data.put(key,value);
return form_data;
* URL decode a string.
* Data passed through the CGI API is URL encoded by the browser.
* All spaces are turned into plus characters (+) and all "special"
* characters are hex escaped into a %dd format (where dd is the hex
* ASCII value that represents the original character). You probably
* won't ever need to call this routine directly; it is used by the
* ReadParse method to decode the form data.
* @param in The string you wish to decode.
* @return The decoded string.
public static String urlDecode(String in)
StringBuffer out = new StringBuffer(in.length());
int i = 0;
int j = 0;
while (i < in.length())
char ch = in.charAt(i);
i++;
if (ch == '+') ch = ' ';
else if (ch == '%')
ch = (char)Integer.parseInt(in.substring(i,i+2), 16);
i+=2;
out.append(ch);
j++;
return new String(out);
* Generate a standard HTTP HTML header.
* @return A String containing the standard HTTP HTML header.
public static String Header()
return "Content-type: text/html\n\n";
* Generate some vanilla HTML that you usually
* want to include at the top of any HTML page you generate.
* @param Title The title you want to put on the page.
* @return A String containing the top portion of an HTML file.
public static String HtmlTop(String Title)
String Top = new String();
Top = "<html>\n";
Top+= "<head>\n";
Top+= "<title>\n";
Top+= Title;
Top+= "\n";
Top+= "</title>\n";
Top+= "</head>\n";
Top+= "<body>\n";
return Top;
* Generate some vanilla HTML that you usually
* want to include at the bottom of any HTML page you generate.
* @return A String containing the bottom portion of an HTML file.
public static String HtmlBot()
return "</body>\n</html>\n";
* Determine if the REQUEST_METHOD used to
* send the data from the browser was the GET method.
* @return true, if the REQUEST_METHOD was GET. false, otherwise.
public static boolean MethGet()
String RequestMethod = System.getProperty("cgi.request_method");
boolean returnVal = false;
if (RequestMethod != null)
if (RequestMethod.equals("GET") ||
RequestMethod.equals("get"))
returnVal=true;
return returnVal;
* Determine if the REQUEST_METHOD used to
* send the data from the browser was the POST method.
* @return true, if the REQUEST_METHOD was POST. false, otherwise.
public static boolean MethPost()
String RequestMethod = System.getProperty("cgi.request_method");
boolean returnVal = false;
if (RequestMethod != null)
if (RequestMethod.equals("POST") ||
RequestMethod.equals("post"))
returnVal=true;
return returnVal;
* Determine the Base URL of this script.
* (Does not include the QUERY_STRING (if any) or PATH_INFO (if any).
* @return The Base URL of this script as a String.
public static String MyBaseURL()
String returnString = new String();
returnString = "http://" +
System.getProperty("cgi.server_name");
if (!(System.getProperty("cgi.server_port").equals("80")))
returnString += ":" + System.getProperty("cgi.server_port");
returnString += System.getProperty("cgi.script_name");
return returnString;
* Determine the Full URL of this script.
* (Includes the QUERY_STRING (if any) or PATH_INFO (if any).
* @return The Full URL of this script as a String.
public static String MyFullURL()
String returnString;
returnString = MyBaseURL();
returnString += System.getProperty("cgi.path_info");
String queryString = System.getProperty("cgi.query_string");
if (queryString.length() > 0)
returnString += "?" + queryString;
return returnString;
* Neatly format all of the CGI environment variables
* and the associated values using HTML.
* @return A String containing an HTML representation of the CGI environment
* variables and the associated values.
public static String Environment()
String returnString;
returnString = "<dl compact>\n";
returnString += "<dt>CONTENT_TYPE <dd>:" +
System.getProperty("cgi.content_type") +
": \n";
returnString += "<dt>CONTENT_LENGTH <dd>:" +
System.getProperty("cgi.content_length") +
": \n";
returnString += "<dt>REQUEST_METHOD <dd>:" +
System.getProperty("cgi.request_method") +
": \n";
returnString += "<dt>QUERY_STRING <dd>:" +
System.getProperty("cgi.query_string") +
": \n";
returnString += "<dt>SERVER_NAME <dd>:" +
System.getProperty("cgi.server_name") +
": \n";
returnString += "<dt>SERVER_PORT <dd>:" +
System.getProperty("cgi.server_port") +
": \n";
returnString += "<dt>SCRIPT_NAME <dd>:" +
System.getProperty("cgi.script_name") +
": \n";
returnString += "<dt>PATH_INFO <dd>:" +
System.getProperty("cgi.path_info") +
": \n";
returnString += "</dl>\n";
return returnString;
* Neatly format all of the form data using HTML.
* @param form_data The Hashtable containing the form data which was
* parsed using the ReadParse method.
* @return A String containing an HTML representation of all of the
* form variables and the associated values.
public static String Variables(Hashtable form_data)
String returnString;
returnString = "<dl compact>\n";
for (Enumeration e = form_data.keys() ; e.hasMoreElements() ;)
String key = (String)e.nextElement();
String value = (String)form_data.get(key);
returnString += "<dt>" + key + " <dd>:" +
value +
": \n";
returnString += "</dl>\n";
return returnString;
* The main routine is included here as a test CGI script to
* demonstrate the use of all of the methods provided above.
* You can use it to test your ability to execute a CGI script written
* in Java. See the sample UNIX script file included above to see
* how you would invoke this routine.
* Please note that this routine references the member functions directly
* (since they are in the same class), but you would have to
* reference the member functions using the class name prefix to
* use them in your own CGI application:
* <pre>
* System.out.println(cgi_lib.HtmlTop());
* </pre>
* @param args An array of Strings containing any command line
* parameters supplied when this program in invoked. Any
* command line parameters supplied are ignored by this routine.
public static void main( String args[] )
// This main program is simply used to test the functions in the
// cgi_lib class.
// That said, you can use this main program as a test cgi script. All
// it does is echo back the form inputs and enviroment information to
// the browser. Use the testcgi UNIX script file to invoke it. You'll
// notice that the script you use to invoke any Java application that
// uses the cgi_lib functions MUST pass all the CGI enviroment variables
// into it using the -D parameter. See testcgi for more details.
// Print the required CGI header.
System.out.println(Header());
// Create the Top of the returned HTML
// page (the parameter becomes the title).
System.out.println(HtmlTop("Hello World"));
System.out.println("<hr>");
// Determine the request method used by the browser.
if (MethGet())
System.out.println("REQUEST_METHOD=GET");
if (MethPost())
System.out.println("REQUEST_METHOD=POST");
System.out.println("<hr>");
// Determine the Base URL of this script.
System.out.println("Base URL: " + MyBaseURL());
System.out.println("<hr>");
// Determine the Full URL used to invoke this script.
System.out.println("Full URL: " + MyFullURL());
System.out.println("<hr>");
// Print all the CGI environment variables
// (usually only used while testing CGI scripts).
System.out.println(Environment());
System.out.println("<hr>");
// Parse the form data into a Hashtable.
Hashtable form_data = ReadParse(System.in);
// Print out each of the name/value pairs
// from sent from the browser.
System.out.println(Variables(form_data));
System.out.println("<hr>");
// Access a particular form value.
// (This assumes the form contains a "name" input field.)
String name = (String)form_data.get("name");
System.out.println("Name=" + name);
System.out.println("<hr>");
// Create the Bottom of the returned HTML page - which closes it cleanly.
System.out.println(HtmlBot());
SERVER-SIDE PROGRAM TO RETURN PING
import java.util.*;
import java.io.*;
class ping
 public static void main(String args[]) {
 System.out.println(cgi_lib.Header());
 Hashtable form_data = cgi_lib.ReadParse(System.in);
 String one = (String)form_data.get("first");
 String two = (String)form_data.get("last");
 boolean test;
 test = false;
 if (one.equals("I am")) {
 if (two.equals("number 1")) {
 test = true;
 if (test == true) {
 System.out.println("pass");
 } else {
 System.out.println("fail");
 //Datavasee
ENJOY :)

Using thread and socket connection with other machines

Hi all!
we are using weblgoic 5.1 SP9 JDK1.2.2
we already using java.net.Socket and java.lang.Thread
to communication TANDEM Machine on the weblogic.
the reason why we use to socket and thread even though it is not
recommanded is that below
1. once we connect Socket, then we using until server shutdown or
connection may has the problem, so we're using thread to wait
java.io.Inputstream to read from socket.(if I using EJB, It can't
wait socket inputstream indefinetly, because it has timeout)
2. we're logging Database date sent or received with TANDEM Machine.
so we need Database Access. so we using Database Access
thru Weblogic.
3. EJB Application using (other EJB Application - send Module)
to send data to TANDEM Machine. So "Send Module" should
be implemented EJB.
but. Now I see there might be problem this framework.
so, is there some way by just using J2EE spec, to implement this kind of
framework.
wait for your great help !!
regards.

Yes i've tried interrupt method and it doesn't have any effects on the thread... it stay in connect() method...
And for the timeouts, in fact i use an API : J2SSH, to connect with SSH protocol, and the setting of connection timeouts is not implemented yet... and the default timeout is about 4 minutes...
so i don't know how to solve this problem...

How to manage socket communications

i need to learn about how to manage socket communications. does any one has sample codes to share that illustrates how to manage sockets? Im going to create an application that listens over a socket. My socket listener should be able to read over the socket continuously without user intervention. If there's no data, it would wait until something comes in. If some data come in, the listener should be able to read it automatically, and save data in db.
Im thinking of an infinite loop here, but the problem
arises when the socket is waiting for data to come in. The application consumes 100% CPU resources. And im only running one instance of my socket listener. My solution here is to use threads and let the thread SLEEP for a while when no there's no data yet.
Any advise on this matter is very much appreciated. Thank you.

It sounds, that you are using non-blocking read from a socket inside a busy wait loop. You should do a blocking read, which means your process/thread will be suspended by OS untill something is available on your socket.
I'm new to Java and I can not say how actually to implement this, but look for "blocking/non-blocking read" in network interface documentation.
Zhenya.

Socket Communications

Socket communications over http-proxy.
Is this a failure of Sun Java?? Its an useful and compulsury nessacity for java programmers.
Any help is accepted

Thanx for your early advice. But I did the same what you told. It works fine with URLConnections.
But I'm using java.net.Socket and java.net.ServerSocket.
I need to use this plain socket for my communications. But connections over this socket with http-proxy fails.
Any help is welcomed..........

How to interchange data between Java Program and C++ Program

I constructed a java program using netbeans IDE that has ability to connect with a respective DLL; I want to connect and interchange data between my java program(.jar) and VSC++ program(.exe) through DLLs.JNI uses single Dll to invoke C/C++ function in native manner,In order to increase the efficiency I tried to connect and interchange primitive data types between Java program and C++ program using that DLL(JNI implemented).
Unfortunately C++ program cannot obtain data values that has been changed by Java Program.For example - If I declare a global int variable in DLL,java program can catch that int variable and can update it but If I run my C++ program(exe) loading same DLL simultaneously it cannot receive the updated value of that int variable declared in the DLL.
Therefore I need a solution to share/Interchange at least primitive data and their respective values between a JAVA and C++ Program using JNI (in spite of date transferring through Sockets).JAVA TO C/C++ & C/C++ to JAVA using DLLs.
(TWO WAY COMMUNICATION)
JAVA.jar <=> <JNI> <=> DLL <=> [Connector Program C/C++] <=> C/C++ .exe
PLEASE HELP ME!! THANK YOU

What in the are you trying to say? What does "filled into the servlet mean?" Is the map somewhere outside the servlet? In a different process? Are you asking how to extract data from a map? Something else?
Sorry, but your question makes no sense.

Java WD and Socket Communication

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