Showing posts with label cilent-server. Show all posts
Showing posts with label cilent-server. Show all posts

Monday, August 20, 2012

Getting started with JAX-WS

JAX-WS stands for Java API for XML Web Services. It is a Java programming language API for creating web services and clients that communicate using XML. This post is a quick start for JAX-WS.

Prerequisites
GlassFish integrated with Eclipse.

Creating the JAX-WS Web Service
  1. In Eclipse create a Dynamic Web Project called "com.eviac.blog.jaxwsproj". Make GlassFish as the Target Runtime.
  2. Create a new class called "SampleWS" in the created project. This will be the implementation class of the web service.
    SampleWS.java
    package com.eviac.blog.jaxws.service;
    
    import javax.jws.WebMethod;
    import javax.jws.WebService;
    
    @WebService
    public class SampleWS {
    
     @WebMethod
     public int sum(int a, int b) {
      return a + b;
     }
    
     @WebMethod
     public int multiply(int a, int b) {
      return a * b;
     }
    
    }
    
    
  3. Open a terminal and navigate to the root of the project directory. Create a directory called wsdl inside WebContent/WEB-INF/. Use the following command to create web service artifacts. Make sure your JAVA_ HOME is set properly or this command will not work. Also make sure to build the project before running this command or it will complain class not found.
    wsgen -classpath build/classes/ -wsdl -r WebContent/WEB-INF/wsdl -s src -d build/classes/ com.eviac.blog.jaxws.service.SampleWS
    
  4. Refresh the project to discover created artifacts. Open the created WSDL-file inside wsdl folder. Search for REPLACE_WITH_ACTUAL_URL and replace it with the web service URL: http://localhost:8080/com.eviac.blog.jaxwsproj/SampleWSService, and save the file.
  5. Deploy the project in Glassfish by right-clicking the project, click Run As -> Run on Server and select the Glassfish server.
Creating the JAX-WS client
  1. Create a Java project in eclipse called "com.eviac.blog.jaxwsclientproj". Open up a new terminal and go to the project root. Use the following command to generate the classes you need to access the web service. Here you will need to use the URL of the WSDL file.
    wsimport -s src -d bin http://localhost:8080/com.eviac.blog.jaxwsproj/SampleWSService?wsdl
    
  2. Create a new class called "SampleWSClient" in the project.
    SampleWSClient.java
    package com.eviac.blog.jaxws.client;
    
    import javax.xml.ws.WebServiceRef;
    
    import com.eviac.blog.jaxws.service.SampleWS;
    import com.eviac.blog.jaxws.service.SampleWSService;
    
    public class SampleWSClient {
    
     @WebServiceRef(wsdlLocation = "http://localhost:8080/com.eviac.blog.jaxwsproj/SampleWSService?wsdl")
     private static SampleWSService Samplews;
    
     public static void main(String[] args) {
      SampleWSClient wsClient = new SampleWSClient();
      wsClient.run();
     }
    
     public void run() {
      Samplews = new SampleWSService();
      SampleWS port = Samplews.getSampleWSPort();
      System.out.println("multiplication Result= "+ port.multiply(10, 20));
      System.out.println("Addition Result= "+port.sum(10, 20));
     }
    
    }
    
  3. Right click on the project and click on Run As -> Java Application. This will result following.
    multiplication Result= 200
    Addition Result= 30
    

Sunday, January 2, 2011

Synchronous Cilent Server application in java

Client code

Client.java

This program creates a socket connection with the server running on port 9050 on localhost and gets the input stream from the socket by chaining the BufferedReader with the InputStreamReader.


package clientserver;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.net.UnknownHostException;

public class client {

 public static void main(String args[]) {

  try {
   Socket s = new Socket("127.0.0.1", 9050);

   InputStreamReader streamreader = new InputStreamReader(
     s.getInputStream());
   BufferedReader br = new BufferedReader(streamreader);

   String number = br.readLine();

   System.out.println("Today's number is " + number);
   br.close();

  } catch (UnknownHostException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }

 }

}



Server code

Server.java

This program makes a ServerSocket and waits for client Requests. When a client tries to connect the server creates a new socket in a random port(using accept() method), which knows about the ip address and the port number of the client and makes the connection to the client. Also here server uses PrintWriter to sned messages to client.


package mainserver;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;

public class Server {

 public static void main(String args[]) {

  try {
   ServerSocket serverSock = new ServerSocket(9050);

   while (true) {

    Socket sock = serverSock.accept();
    PrintWriter pw = new PrintWriter(sock.getOutputStream());
    String TodayNum = new Server().getNumber();
    pw.println(TodayNum);
    pw.close();
    System.out.println(TodayNum);

   }

  } catch (IOException e) {
   e.printStackTrace();
  }

 }

 public String getNumber() {

  Random rg = new Random();
  int num = rg.nextInt(100);
  String numb = Integer.toString(num);
  return numb;

 }

}



Output

Sunday, December 5, 2010

Asynchronous Client Server in C#

AsynchronousSocketListener.cs

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using StateObjectns;


namespace AsynchronousSocketListenerns
{

    public class AsynchronousSocketListener
    {
        // Thread signal.
        public static ManualResetEvent allDone = new ManualResetEvent(false);

        public AsynchronousSocketListener()
        {
        }

        public static void StartListening()
        {
            // Data buffer for incoming data.
            byte[] bytes = new Byte[1024];

            // Establish the local endpoint for the socket.
            // The DNS name of the computer
            // running the listener is "host.contoso.com".
            IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
            IPAddress ipAddress = ipHostInfo.AddressList[0];
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);

            // Create a TCP/IP socket.
            Socket listener = new Socket(AddressFamily.InterNetwork,
                SocketType.Stream, ProtocolType.Tcp);

            // Bind the socket to the local endpoint and listen for incoming connections.
            try
            {
                listener.Bind(localEndPoint);
                listener.Listen(100);

                while (true)
                {
                    // Set the event to nonsignaled state.
                    allDone.Reset();

                    // Start an asynchronous socket to listen for connections.
                    Console.WriteLine("Waiting for a connection...");
                    listener.BeginAccept(
                        new AsyncCallback(AcceptCallback),
                        listener);

                    // Wait until a connection is made before continuing.
                    allDone.WaitOne();
                }

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }

            Console.WriteLine("\nPress ENTER to continue...");
            Console.Read();

        }

        public static void AcceptCallback(IAsyncResult ar)
        {
            // Signal the main thread to continue.
            allDone.Set();

            // Get the socket that handles the client request.
            Socket listener = (Socket)ar.AsyncState;
            Socket handler = listener.EndAccept(ar);

            // Create the state object.
            StateObject state = new StateObject();
            state.workSocket = handler;
            handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReadCallback), state);
        }

        public static void ReadCallback(IAsyncResult ar)
        {
            String content = String.Empty;

            // Retrieve the state object and the handler socket
            // from the asynchronous state object.
            StateObject state = (StateObject)ar.AsyncState;
            Socket handler = state.workSocket;

            // Read data from the client socket. 
            int bytesRead = handler.EndReceive(ar);

            if (bytesRead > 0)
            {
                // There  might be more data, so store the data received so far.
                state.sb.Append(Encoding.ASCII.GetString(
                    state.buffer, 0, bytesRead));

                // Check for end-of-file tag. If it is not there, read 
                // more data.
                content = state.sb.ToString();
                if (content.IndexOf("<eof>") > -1)
                {
                    // All the data has been read from the 
                    // client. Display it on the console.
                    Console.WriteLine("Read {0} bytes from socket. \n Data : {1}",
                        content.Length, content);
                    // Echo the data back to the client.
                    Send(handler, content);
                }
                else
                {
                    // Not all data received. Get more.
                    handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReadCallback), state);
                }
            }
        }

        private static void Send(Socket handler, String data)
        {
            // Convert the string data to byte data using ASCII encoding.
            byte[] byteData = Encoding.ASCII.GetBytes(data);

            // Begin sending the data to the remote device.
            handler.BeginSend(byteData, 0, byteData.Length, 0,
                new AsyncCallback(SendCallback), handler);
        }

        private static void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = handler.EndSend(ar);
                Console.WriteLine("Sent {0} bytes to client.", bytesSent);

                handler.Shutdown(SocketShutdown.Both);
                handler.Close();

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        public void init()
        {
           

                StartListening();
            
        }
        
    }
}


AsynchronousClient.cs

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Text;
using StateObjectns;

namespace AsynchronousClientns
{

    public class AsynchronousClient
    {
        // The port number for the remote device.
        private const int port = 11000;

        // ManualResetEvent instances signal completion.
        private static ManualResetEvent connectDone =
            new ManualResetEvent(false);
        private static ManualResetEvent sendDone =
            new ManualResetEvent(false);
        private static ManualResetEvent receiveDone =
            new ManualResetEvent(false);

        // The response from the remote device.
        private static String response = String.Empty;

        private static void StartClient()
        {
            // Connect to a remote device.
            try
            {
                // Establish the remote endpoint for the socket.
                // The name of the 
                // remote device is "host.contoso.com".
                IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
                IPAddress ipAddress = ipHostInfo.AddressList[0];
                IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);

                // Create a TCP/IP socket.
                Socket client = new Socket(AddressFamily.InterNetwork,
                    SocketType.Stream, ProtocolType.Tcp);

                // Connect to the remote endpoint.
                client.BeginConnect(remoteEP,
                    new AsyncCallback(ConnectCallback), client);
                connectDone.WaitOne();

                // Send test data to the remote device.
                Send(client, "This is a test<eof>");
                sendDone.WaitOne();

                // Receive the response from the remote device.
                Receive(client);
                receiveDone.WaitOne();

                // Write the response to the console.
                Console.WriteLine("Response received : {0}", response);

                // Release the socket.
                client.Shutdown(SocketShutdown.Both);
                client.Close();

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        private static void ConnectCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;

                // Complete the connection.
                client.EndConnect(ar);

                Console.WriteLine("Socket connected to {0}",
                    client.RemoteEndPoint.ToString());

                // Signal that the connection has been made.
                connectDone.Set();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        private static void Receive(Socket client)
        {
            try
            {
                // Create the state object.
                StateObject state = new StateObject();
                state.workSocket = client;

                // Begin receiving the data from the remote device.
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        private static void ReceiveCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the state object and the client socket 
                // from the asynchronous state object.
                StateObject state = (StateObject)ar.AsyncState;
                Socket client = state.workSocket;

                // Read data from the remote device.
                int bytesRead = client.EndReceive(ar);

                if (bytesRead > 0)
                {
                    // There might be more data, so store the data received so far.
                    state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                    // Get the rest of the data.
                    client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                        new AsyncCallback(ReceiveCallback), state);
                }
                else
                {
                    // All the data has arrived; put it in response.
                    if (state.sb.Length > 1)
                    {
                        response = state.sb.ToString();
                    }
                    // Signal that all bytes have been received.
                    receiveDone.Set();
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        private static void Send(Socket client, String data)
        {
            // Convert the string data to byte data using ASCII encoding.
            byte[] byteData = Encoding.ASCII.GetBytes(data);

            // Begin sending the data to the remote device.
            client.BeginSend(byteData, 0, byteData.Length, 0,
                new AsyncCallback(SendCallback), client);
        }

        private static void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = client.EndSend(ar);
                Console.WriteLine("Sent {0} bytes to server.", bytesSent);

                // Signal that all bytes have been sent.
                sendDone.Set();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        public void init()
        {
            

                StartClient();
            
        }
    }
}




StateObject.cs

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

namespace StateObjectns
{

    // State object for reading client/server data asynchronously
    public class StateObject
    {
        // Client  socket.
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 1024;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
        // Received data string.
        public StringBuilder sb = new StringBuilder();
    }
}


MainRun.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using StateObjectns;
using AsynchronousClientns;
using System.Threading;
using AsynchronousSocketListenerns;


namespace MainRunns
{
    class Program
    {
        static void Main(string[] args)
        {
            Thread servertr = new Thread(new AsynchronousSocketListener().init);
            Thread clienttr = new Thread(new AsynchronousClient().init);

            servertr.Start();
            clienttr.Start();

            Console.ReadLine();

        }
    }
}
AsynchronousSocketListenerns.cs creates a server that receives connection requests from clients. The server is built with an asynchronous socket, so execution of the server application is not suspended while it waits for a connection from a client. The application receives a string from the client, displays the string on the console, and then echoes the string back to the client. The string from the client must contain the string "<eof>" to signal the end of the message.

AsynchronousClient.cs creates a client that connects to a server. As client is built with an asynchronous socket, execution of the client application is not suspended while the server returns a response. The application sends a string to the server and then displays the string returned by the server on the console.

StateObject.cs is used for reading client/server data asynchronously.

MainRunns.cs is used to start a server thread and a client thread.

OutputScreen

references : http://msdn.microsoft.com/

Thursday, December 2, 2010

Synchronous Client Server Application in C#

TCP Based Server

  • Establish the local end point for the socket
  • Open a socket using Socket()
  • Name the socket using Bind()
  • Listen for incoming connections using Listen(), parameter inside the method specifies the maximu number of pending connections
  • Accept client connections using Accept(), a new socket is created here but the original socket keeps listen
  • Send, Receive data using Send() and Receive()
  • Close Socket using Close()

Server.cs

   using System; 
   using System.Net.Sockets; 
   using System.Net; 
   using System.Text; 

   public class SocketServer 
   { 
      public static void Main(string [] args) 
      { 

         // establish the local end point for the socket 
         IPHostEntry ipHost = Dns.Resolve("localhost"); 
         IPAddress ipAddr = ipHost.AddressList[0]; 
         IPEndPoint ipEndPoint = new IPEndPoint(ipAddr, 11000); 

         // create a Tcp/Ip Socket 
         Socket sListener = new Socket(AddressFamily.InterNetwork, 
                                       SocketType.Stream, ProtocolType.Tcp); 

         // bind the socket to the local endpoint and 
         // listen to the incoming sockets 

         try 
         { 
            sListener.Bind(ipEndPoint); 
            sListener.Listen(10); 

            // Start listening for connections 

            while (true) 
            { 
               Console.WriteLine("Waiting for a connection on port {0}",ipEndPoint); 

               // program is suspended while waiting for an incoming connection 
               Socket handler = sListener.Accept(); 

               string data = null; 

               // we got the client attempting to connect 
               while(true) 
               { 
                  byte[] bytes = new byte[1024]; 

                  int bytesRec = handler.Receive(bytes); 

                  data += Encoding.ASCII.GetString(bytes, 0, bytesRec); 

                  if (data.IndexOf("<theend>") > -1) 
                  { 
                     break; 
                  } 
               } 

               // show the data on the console 
               Console.WriteLine("Text Received: {0}",data); 

               string theReply = "Thank you for those " + data.Length.ToString() 
                               + " characters..."; 
               byte[] msg = Encoding.ASCII.GetBytes(theReply); 

               handler.Send(msg); 
               handler.Shutdown(SocketShutdown.Both); 
               handler.Close(); 
            } 
         } 
         catch(Exception e) 
         { 
            Console.WriteLine(e.ToString()); 
         } 

      } // end of Main 
   } 



TCP Based Client

  • Establish a remote endpoint
  • Open a socket using Socket()
  • Connect to the remote host using Connect
  • Send, receive data using Send() and Receive()
  • Close Socket using Close()

Client.cs

using System; 
using Systern.Net.Sockets; 
using Systern.Net; 
using Systern.Text; 

public class SocketClient 
{ 
   public static void Main(string [] args) 
   {

    // data buffer for incoming data 
    byte[] bytes = new byte[1024]; 

    // connect to a Remote device 
    try 
    { 
       // Establish the remote end point for the socket 
       IPHostEntry ipHost = Dns.Resolve("127.0.0.1"); 
       IPAddress ipAddr = ipHost.AddressList[0]; 
       IPEndPoint ipEndPoint = new IPEndPoint(ipAddr, 11000); 

       Socket sender = new Socket(AddressFamily.Internetwork, 
                                  SocketType.Stream, ProtocolType.Tcp); 

       // Connect the socket to the remote endpoint 

          sender.Connect(ipEndPoint); 

          Console.WriteLine("Socket connected to {0}", 
          sender.RemoteEndPoint.ToString()); 

          string theMessage = "This is a test"; 

          byte[] msg = Encoding.ASCII.GetBytes(theMessage+"<theend>"); 

          // Send the data through the socket 
          int bytesSent = sender.Send(msg); 

          // Receive the response from the remote device 
          int bytesRec = sender.Receive(bytes); 

          Console.WriteLine("The Server says : {0}", 
                            Encoding.ASCII.GetString(bytes,0, bytesRec)); 

          // Release the socket 
          sender.Shutdown(SocketShutdown.Both); 
          sender.Close(); 

    } 
    catch(Exception e) 
    { 
       Console.WriteLine("Exception: {0}", e.ToString()); 
    } 
  } 
} 



Fllowing image shows how client and server send and receive data

Saturday, November 27, 2010

Sockets

Sockets

  • Socket is one end of a two way communication link between two programs running on a network.
  • Data can be passed between different processes by connecting the two sockets together

Basic socket types

  • Stream Socket
    • Connection oriented sockets
    • Consists of a stream of bytes that can be bi-directional
    • Usage of stream sockets is a more reliable method than the usage of datagram sockets
  • Datagram sockets
    • AKA Connectionless sockets, no explicit connection is established
    • A message is sent to a specified socket and can be received appropriately from the specified socket
    • Usage of datagram sockets is reducing the overhead incurred by establishing an explicit connection

Row sockets

  • Generalized form of sockets called row sockets
  • Packet is passed directly to the application that needs it bypassing the mechanism by which the computer handles TCP/IP

Ports

  • Defined to solve the problem of communicating with multiple operations simultaneously

Sockets composed of
  • IP address of the machine
  • Port no used by TCP application

Socket numbers are unique across the entire internet as IP address is unique across the internet and the port no is unique on the individual machine. This enables process to communicate with another process across network based entirely on socket number.

Client Server applications uses sockets

  • Server waits for the connection from the client
  • Client initiates the connection with the server
  • Server should be already running before client tries to connect
  • Client must know the target address and the port no, tries to establish a connection with the server
  • Server accepts the connection
  • Server application creates a new socket to deal specifically with the connected client
  • Server and client communicate by reading from and writing to their respective sockets