added-tcp-server-and-client

TCPClient.java

@@ -0,0 +1,23 @@
+import java.io.*;
+import java.net.*;
+
+class TCPClient {
+	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", 4444); 
+
+	DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
+	BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+	System.out.println("Enter a message:");
+	sentence = inFromUser.readLine();
+	outToServer.writeBytes(sentence + '\n');
+	modifiedSentence = inFromServer.readLine();
+	System.out.println("FROM SERVER: " + modifiedSentence);
+	clientSocket.close();
+	} 
+} 

TCPServer.java

@@ -0,0 +1,42 @@
+import java.io.*; 
+import java.net.*; 
+class Thr extends Thread
+{
+	Socket s;
+
+	Thr(){s=null; }
+
+	Thr(Socket s1) { s=s1;}
+
+	public void run()
+	{
+		String clientSentence;
+		String capitalizedSentence;
+		try{
+			BufferedReader inFromClient =new BufferedReader(new InputStreamReader(s.getInputStream()));
+			DataOutputStream outToClient=new DataOutputStream(s.getOutputStream()); 
+			clientSentence = inFromClient.readLine();
+			System.out.println(clientSentence);
+			capitalizedSentence = clientSentence.toUpperCase() + '\n';
+			outToClient.writeBytes(capitalizedSentence);
+			s.close();
+			if(clientSentence.equals("exit"))
+				 System.exit(1);
+
+		} 
+		catch(Exception e){}
+		}
+
+		}
+		class TCPServer {
+			public static void main(String argv[]) throws Exception {
+
+			ServerSocket dataReceive = new ServerSocket(4444);
+
+			while(true) {
+			Socket connectionSocket = dataReceive.accept();
+			 Thr t=new Thr(connectionSocket);
+			 t.start();
+		} 
+	} 
+}