add TCP apps

TCP/TCPReceiver.java

+import java.io.*;
+import java.net.*;
+class TCPReceiver {
+    public static void main(String[] args) {
+        try {
+            ServerSocket ss = new ServerSocket(4322);
+            for (;;) {
+                try {
+                    Socket client = ss.accept();
+                    BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
+                    String line;
+                    while ((line = in .readLine()) != null) System.out.println(line + " received");
+                    client.close();
+                } catch (Exception e) {
+                    System.out.println("error " + e);
+                }
+            }
+        } catch (Exception e) {
+            System.out.println("error " + e);
+        }
+    }
+}

TCP/TCPSender.java

+import java.io.*;
+import java.net.*;
+class TCPSender {
+    public static void main(String[] args) {
+        try {
+            Socket socket = new Socket("isaac-VirtualBox", 4322);
+            PrintWriter out = new PrintWriter(socket.getOutputStream());
+            for (int i = 0; i < 10; i++) {
+                out.println("TCP message " + i);
+                out.flush();
+                System.out.println("TCP message " + i + " sent");
+                Thread.sleep(1000);
+            }
+        } catch (Exception e) {
+            System.out.println("error" + e);
+        }
+    }
+}