Merge branch 'master' of github.com:pvcraven/networking_down_under

ReceiveMultipleMessages.java

@@ -15,12 +15,16 @@
 public class ReceiveMultipleMessages {
 
     public static void handleConnection() throws Exception {
+        // Modify this to match the computer you are connecting to
+        String ipAddress = "127.0.0.1";
+        int port = 10000;
+
         // Selector: multiplexor of SelectableChannel objects
         Selector channelSelector = Selector.open(); // selector is open here
 
         // ServerSocketChannel: selectable channel for stream-oriented listening sockets
         ServerSocketChannel myServerSocketChannel = ServerSocketChannel.open();
-        InetSocketAddress myAddress = new InetSocketAddress("127.0.0.1", 10000);
+        InetSocketAddress myAddress = new InetSocketAddress(ipAddress, port);
 
         // Binds the channel's socket to a local address and configures the socket to listen for connections
         myServerSocketChannel.bind(myAddress);
@@ -74,26 +78,28 @@ public static void handleConnection() throws Exception {
                 } else if (myKey.isReadable()) {
 
                     SocketChannel myClient = (SocketChannel) myKey.channel();
-                    ByteBuffer myBuffer = ByteBuffer.allocate(2048);
-                    myClient.read(myBuffer);
-                    String result = new String(myBuffer.array()).trim();
-                    fullMessage = fullMessage + result;
-
-                    // System.out.println("Message received: " + result);
-                    chunks += 1;
+                    ByteBuffer myBuffer = ByteBuffer.allocate(65536);
+                    int bytesRead = myClient.read(myBuffer);
+                    String result = new String(myBuffer.array());
+                    result = result.substring(0, bytesRead);
+                    if (result.length() > 0) {
+                        fullMessage = fullMessage + result;
+                        chunks += 1;
+                        System.out.println("Message received " + result.length() + " bytes: \"" + result + "\"");
+                    }
 
-                    if (result.endsWith("Z")) {
+                    if (result.endsWith("\n")) {
                         myClient.close();
-                        myServerSocketChannel.close();
-                        channelSelector.close();
                         done = true;
-                        System.out.println("It's time to close connection as we got a Z");
+                        System.out.println("It's time to close connection as we got a \\n");
                         endTime = System.currentTimeMillis();
                     }
                 }
                 keyIterator.remove();
             }
         }
+        myServerSocketChannel.close();
+        channelSelector.close();
         long totalTime = endTime - startTime;
         System.out.println("Done receiving " + fullMessage.length() + " in " + chunks + " chunks over " + totalTime + " ms.");
     }

ReceiveOneShot.java

@@ -40,8 +40,9 @@ public void setupSocket() throws Exception {
         System.out.println("\nStarting...");
 
     }
-    public void checkConnection() throws Exception {
-
+    public boolean checkConnection() throws Exception {
+        // Set to true when we have our whole message
+        boolean done = false;
 
         // Selects a set of keys whose corresponding channels are ready for I/O operations
         // For blocking I/O use a select with no data:
@@ -72,29 +73,33 @@ public void checkConnection() throws Exception {
                 // Tests whether this key's channel is ready for reading
             } else if (myKey.isReadable()) {
 
-                SocketChannel myClient = (SocketChannel) myKey.channel();
-                ByteBuffer myBuffer = ByteBuffer.allocate(2048);
-                myClient.read(myBuffer);
-                String result = new String(myBuffer.array()).trim();
-
-                System.out.println("Message received: " + result);
+                    SocketChannel myClient = (SocketChannel) myKey.channel();
+                    ByteBuffer myBuffer = ByteBuffer.allocate(65536);
+                    int bytesRead = myClient.read(myBuffer);
+                    String result = new String(myBuffer.array());
+                    result = result.substring(0, bytesRead);
+                    if (result.length() > 0) {
+                        System.out.println("Message received " + result.length() + " bytes: \"" + result + "\"");
+                    }
 
-                if (result.endsWith("Z")) {
+                if (result.endsWith("\n")) {
                     myClient.close();
-                    myServerSocketChannel.close();
-//                    channelSelector.close();
+                    done = true;
                     System.out.println("It's time to close connection as we got a Z");
                 }
             }
             keyIterator.remove();
         }
+        return done;
     }
 
     public static void main(String[] args) throws Exception {
         ReceiveOneShot receiveOneShot = new ReceiveOneShot();
 
         receiveOneShot.setupSocket();
-        while(true)
-            receiveOneShot.checkConnection();
+
+        boolean done = false;
+        while(!done)
+            done = receiveOneShot.checkConnection();
     }
 }

SendMultipleMessages.java

@@ -0,0 +1,55 @@
+import java.io.PrintWriter;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Socket;
+
+public class SendMultipleMessages {
+
+    private static void sendData(int totalBytes, int messageSizeInBytes)
+            throws IOException {
+
+        // Modify this to match to be THIS computer's address
+        String ipAddress = "127.0.0.1";
+        int serverPort = 10000;
+
+        InetAddress serverAddress = InetAddress.getByName(ipAddress);
+        int messagesToSend = totalBytes / messageSizeInBytes;
+
+        String myData = "";
+        for(int i = 0; i < messageSizeInBytes; i++) {
+            myData += "X";
+        }
+
+        Socket socket = new Socket(serverAddress, serverPort);
+
+        // Try changing this to false and see if it changes how packets are sent
+        boolean autoFlush = true;
+        PrintWriter out = new PrintWriter(socket.getOutputStream(), autoFlush);
+
+        for (int i = 0; i < messagesToSend; i++) {
+            out.print(myData);
+            // Try enabling this and see if it changes how packets are sent
+            // out.flush();
+        }
+        out.print("\n");
+
+        out.flush();
+
+        socket.close();
+    }
+    public static void main(String[] args) throws Exception {
+
+        // How many bytes to send
+        int totalBytes = 5000;
+
+        // How big each message will be
+        int messageSizeInBytes = 10;
+
+        System.out.println("Sending " + totalBytes + "bytes in " + messageSizeInBytes + " byte chunks.");
+
+        // Send the data
+        sendData(totalBytes, messageSizeInBytes);
+
+        System.out.println("Done sending message.");
+    }
+}

tcp_send_multiple_messages.py

@@ -4,6 +4,7 @@
 server_ip_address = '127.0.0.1'
 server_ip_port = 10000
 
+
 def send_data(total_bytes, message_size_in_bytes):
     """
     Send a bunch of messages that sum "total_bytes" of data. Break each
@@ -15,7 +16,7 @@ def send_data(total_bytes, message_size_in_bytes):
     # Message as a byte array. (Hence the b at the front.)
     # Send byte array with an X:   b"X"
     # Repeat this (message_size_in_bytes - 1) times.
-    my_message = b"X" * (message_size_in_bytes)
+    my_message = b"X" * (message_size_in_bytes - 1)
 
     # Open a socket
     my_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -36,6 +37,7 @@ def send_data(total_bytes, message_size_in_bytes):
 
     print("Done")
 
+
 def main():
     """ Main program. """
 
@@ -47,4 +49,5 @@ def main():
     print(f"Sending {total_bytes:,} bytes in {message_size_in_bytes} byte chunks.")
     send_data(total_bytes, message_size_in_bytes)
 
-main()
+
+main()