diff --git a/CourseExamples/src/TcpExamples/TcpExample3Client.java b/CourseExamples/src/TcpExamples/TcpExample3Client.java
new file mode 100644
index 0000000000000000000000000000000000000000..87e44dae4ce5de6b80532253e6d2c109ad20e121
--- /dev/null
+++ b/CourseExamples/src/TcpExamples/TcpExample3Client.java
@@ -0,0 +1,55 @@
+package TcpExamples;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * Before, we always used telnet to connect to the server. Here we are now
+ * writing our own program to do the connection.
+ *
+ * As you will see, when we run this after we start the server we will see the
+ * same string telnet printed, sent by the server. The output at the server will
+ * show different socket pairs for each time we ran it.
+ *
+ * @author mcgredo
+ */
+public class TcpExample3Client {
+
+ // IPv6 String constant for localhost address, similarly IPv4 127.0.0.1
+ public final static String LOCALHOST = "0:0:0:0:0:0:0:1";
+
+ public static void main(String[] args) {
+ try {
+ while (true) {
+ System.out.println("TcpExample3Client creating socket...");
+
+ // We request an IP to connect to ("localhost") and
+ // port number at that IP (2317). This establishes
+ // a connection to that IP in the form of the Socket
+ // object; the server uses a ServerSocket to wait for
+ // connections.
+ Socket socket = new Socket(LOCALHOST, 2317); // locohost?
+
+ // Now hook everything up (i.e. set up the streams), Java style:
+ InputStream is = socket.getInputStream();
+ InputStreamReader isr = new InputStreamReader(is);
+ BufferedReader br = new BufferedReader(isr);
+
+ // Read the single line written by the server. We'd
+ // do things a bit differently if many lines to be read
+ // from the server, instead of one only.
+ String serverMessage = br.readLine();
+ System.out.println("==================================================");
+ System.out.println("Now we're talking!");
+ System.out.println("The message the server sent was " + serverMessage);
+ // socket gets closed, either automatically/silently this code (or possibly by server)
+ } // end while(true)
+ }
+ catch (IOException e) {
+ System.out.println("Problem with client: "); // describe what is happening
+ System.out.println(e);
+ }
+ // program exit: tell somebody about that
+ System.out.println("client exit");
+ }
+}
diff --git a/CourseExamples/src/TcpExamples/TcpExample3Server.java b/CourseExamples/src/TcpExamples/TcpExample3Server.java
new file mode 100644
index 0000000000000000000000000000000000000000..d1da0e1d6be36bdfdc540923f0e5719e11549835
--- /dev/null
+++ b/CourseExamples/src/TcpExamples/TcpExample3Server.java
@@ -0,0 +1,80 @@
+package TcpExamples;
+
+import java.io.*;
+import java.net.*;
+
+/**
+ * Very slightly more complex than example1. A complete copy of example 2. The
+ * only thing this does differently is introduce a loop into the response, so
+ * you don't have to restart the program after one response. Also, it prints out
+ * the socket pair the server sees. Run the program via telnet several times and
+ * compare the socket pairs.
+ *
+ * telnet localhost 2317
+ *
+ * If you're sophisticated you can contact the instructor's computer while
+ * running this program.
+ *
+ * telnet [ipNumberOfServerLaptop] 2317
+ *
+ * And have him display the socket pairs he got.
+ *
+ * @author mcgredo
+ */
+public class TcpExample3Server {
+
+ @SuppressWarnings("ConvertToTryWithResources")
+ public static void main(String[] args)
+ {
+ try {
+ // ServerSocket waits for a connection from a client.
+ // Notice that it is outside the loop; ServerSocket
+ // needs to be made only once.
+
+ System.out.println("TcpExample3Server has started..."); // it helps debugging to put this on console first
+ ServerSocket serverSocket = new ServerSocket(2317);
+
+ // Server is up and waiting (i.e. "blocked" or paused)
+ // Loop, infinitely, waiting for client connections.
+ // Stop the program somewhere else.
+ while (true)
+ {
+ Socket clientConnection = serverSocket.accept(); // block until connected to a client
+
+ // Now hook everything up (i.e. set up the streams), Java style:
+ OutputStream os = clientConnection.getOutputStream();
+ PrintStream ps = new PrintStream(os);
+
+ ps.println("This was written by the server"); // this goes back to client!
+
+ // Print some information locally about the Socket
+ // connection. This includes the port and IP numbers
+ // on both sides (the socket pair.)
+ InetAddress localAddress = clientConnection.getLocalAddress();
+ InetAddress remoteAddress = clientConnection.getInetAddress();
+
+ int localPort = clientConnection.getLocalPort();
+ int remotePort = clientConnection.getPort();
+
+ // My socket pair connection looks like this, to localhost:
+ // Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 54876 ))
+ // Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 54881 ))
+ //
+ // Why is the first IP/port the same, while the second set has
+ // different ports?
+ System.out.println("Socket pair: (( " + localAddress.toString() + ", " + localPort + " ), ( "
+ + remoteAddress.toString() + ", " + remotePort + " ))");
+
+ // Notice the use of flush() and close(). Without
+ // the close() to Socket object may stay open for
+ // a while after the client has stopped needing this
+ // connection. Close() explicitly ends the connection.
+ ps.flush();
+ clientConnection.close(); // like it or not, you're outta here!
+ }
+ }
+ catch (IOException e) {
+ System.out.println("problem with networking");
+ }
+ }
+}
diff --git a/CourseExamples/src/TcpExamples/TcpExample3TerminalLog.txt b/CourseExamples/src/TcpExamples/TcpExample3TerminalLog.txt
new file mode 100644
index 0000000000000000000000000000000000000000..94370eb8f371459a47ca9e4ccd95ae7caea67e18
--- /dev/null
+++ b/CourseExamples/src/TcpExamples/TcpExample3TerminalLog.txt
@@ -0,0 +1,24 @@
+run:
+TcpExample3Server has started...
+Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 49239 ))
+Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 49240 ))
+Socket pair: (( /0:0:0:0:0:0:0:1, 2317 ), ( /0:0:0:0:0:0:0:1, 49241 ))
+[etc.]
+
+
+run:
+TcpExample3Client creating socket...
+==================================================
+Now we're talking!
+The message the server sent was This was written by the server
+TcpExample3Client creating socket...
+==================================================
+Now we're talking!
+The message the server sent was This was written by the server
+TcpExample3Client creating socket...
+==================================================
+Now we're talking!
+The message the server sent was This was written by the server
+TcpExample3Client creating socket...
+==================================================
+[etc.]