Java Very Simple Sever / Client Example

Java Very Simple Sever / Client Example

Some basic code to demonstrate the client/sever link up, this code can be simply modified in to a simple chat room application.

SERVER.java

import java.io.DataOutput;

import java.io.InputStreamReader;

import java.io.DataOutputStream;

import java.io.BufferedReader;

import java.net.ServerSocket;

import java.net.Socket;

class server

{

public static void main(String args[]) throws Exception

{

String clientSentence;

String capitalizedSentence;

ServerSocket welcome = new ServerSocket(6789);

while(true)

{

Socket connectionSocket = welcome.accept();

BufferedReader inFromClient =

               new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));

DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());

clientSentence = inFromClient.readLine();

System.out.println("Received : "+clientSentence);

capitalizedSentence=clientSentence.toUpperCase()+"\n";

outToClient.writeBytes(capitalizedSentence);

}

}

}

CLIENT.java

import java.io.DataOutput;

import java.io.InputStreamReader;

import java.io.DataOutputStream;

import java.io.BufferedReader;

import java.net.ServerSocket;

import java.net.Socket;

class client

{

 public static void main(String argv[]) throws Exception

 {

  String sentence;

  String modifiedSentence;

  

  BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));

  Socket clientSocket = new Socket("localhost", 6789);

  DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());

  BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

  

  sentence = inFromUser.readLine();

  outToServer.writeBytes(sentence + '\n');

  modifiedSentence = inFromServer.readLine();

  

  System.out.println("FROM SERVER: " + modifiedSentence);

  clientSocket.close();

 }

}