Network programming help required

Question

Hi there.
I found an example of a radias calculator program that sends results to and from the client/multi threaded server.
I am trying to ammend it so I can send text to server, and echos that back to the client.
So far I am not having much luck at all trying to get this to work. I have seen examples in the tutorial, but I find them radically complicated.
If any experts out there could correct the below, that would be great!!
thanks
CLIENT
// Client.java: The client sends the input to the server and receives
// result back from the server
import java.io.*;
import java.net.*;
public class Client
// Main method
public static void main(String[] args)
try
     BufferedReader ar = null;
     BufferedWriter wr = null;
// Create a socket to connect to the server
Socket connectToServer = new Socket("localhost", 8000);
// Socket connectToServer = new Socket("bellamy.armstrong.edu", 8000);
          //ar = new BufferedReader(new InputStreamReader(new FileInputStream(UserName+ ".txt")));
// Create an input stream to receive data from the server
//DataInputStream isFromServer = new DataInputStream(connectToServer.getInputStream());
          ar = new BufferedReader(new InputStreamReader(connectToServer.getInputStream()));
// Create an output stream to send data to the server
//DataOutputStream osToServer = new DataOutputStream(connectToServer.getOutputStream());
wr = new BufferedWriter(new OutputStreamWriter(connectToServer.getOutputStream()));
// Continuously send radius and receive area from the server
while (true)
// Read the radius from the keyboard
System.out.print("Please enter a radius: ");
//double radius = 5574.5587;     //MyInput.readDouble();
String radius = "55745587";     //MyInput.readDouble();
// Send the radius to the server
//osToServer.write();
//osToServer.flush();
wr.write(radius);
wr.flush();
// Get area from the server
//String area = isFromServer.read("dsds");
String area = ar.read(" ");
// Print area on the console
System.out.println("Area received from the server is "
+ area);
catch (IOException ex)
System.err.println(ex);
MULTI THREADED SERVER
// MultiThreadsServer.java: The server can communicate with
// multiple clients concurrently using the multiple threads
import java.io.*;
import java.net.*;
public class MultiThreadServer
// Main method
public static void main(String[] args)
try
// Create a server socket
ServerSocket serverSocket = new ServerSocket(8000);
// To number a client
int clientNo = 1;
while (true)
// Listen for a new connection request
Socket connectToClient = serverSocket.accept();
// Print the new connect number on the console
System.out.println("Start thread for client " + clientNo);
// Find the client's hostname, and IP address
InetAddress clientInetAddress = connectToClient.getInetAddress();
System.out.println("Client " + clientNo + "'s hostname is "
+ clientInetAddress.getHostName());
System.out.println("Client " + clientNo + "'s IP Address is "
+ clientInetAddress.getHostAddress());
// Create a new thread for the connection
HandleAClient thread = new HandleAClient(connectToClient, clientNo);
// Start the new thread
thread.start();
// Increment clientNo
clientNo++;
catch(IOException ex)
System.err.println(ex);
// Define the thread class for handling a new connection
class HandleAClient extends Thread
private Socket connectToClient; // A connected socket
private int clientNo; // Indicate client no
// Construct a thread
public HandleAClient(Socket socket, int clientNo)
connectToClient = socket;
this.clientNo = clientNo;
// Implement the run() method for the thread
public void run()
try
// Create data input and output streams
// DataInputStream isFromClient = new DataInputStream(connectToClient.getInputStream());
// DataOutputStream osToClient = new DataOutputStream(connectToClient.getOutputStream());
     BufferedReader isFromClient = new BufferedReader(new InputStreamReader(connectToClient.getInputStream()));
BufferedWriter osToClient = new BufferedWriter(new OutputStreamWriter(connectToClient.getOutputStream()));
// Continuously serve the client
while (true)
// Receive radius from the client
String radius = "sss";
isFromClient.read();
System.out.println("radius received from client " +
clientNo + ": " + radius);
// Compute area
String area = radius;
// Send area back to the client
osToClient.write(area);
System.out.println("Area found: " + area);
catch(IOException ex)
System.err.println(ex);

Answer 1

Maybe I missed it, but I don't see a osToClient.flush() in the server. Without it the output will just build up.