Renamed Heartbeat to HeartBeat.

Added HeartBeatDecoder.
Added HeartBeatEncoder.
BinaryMessageDecoder now uses HeartBeatDecoder.
MockOutput now logs a warning if a heartBeat cannot be encoded.
Added HeartBeatDecoderTest.
issue #35 #36
#story[1095]

racevisionGame/src/main/java/mock/app/MockOutput.java

@@ -7,12 +7,9 @@ import network.Exceptions.InvalidMessageException;
 import network.MessageEncoders.RaceVisionByteEncoder;
 import network.Messages.*;
 import network.Messages.Enums.MessageType;
-import network.Messages.Enums.XMLMessageType;
 
 import java.io.DataOutputStream;
 import java.io.IOException;
-import java.net.ServerSocket;
-import java.net.Socket;
 import java.net.SocketException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -101,24 +98,25 @@ public class MockOutput implements Runnable
      * Generates the next heartbeat message and returns it. Increments the heartbeat sequence number.
      * @return The next heartbeat message.
      */
-    private Heartbeat createHeartbeatMessage() {
+    private HeartBeat createHeartbeatMessage() {
 
         //Create the heartbeat message.
-        Heartbeat heartbeat = new Heartbeat(this.heartbeatSequenceNum);
+        HeartBeat heartBeat = new HeartBeat(this.heartbeatSequenceNum);
         heartbeatSequenceNum++;
 
-        return heartbeat;
+        return heartBeat;
     }
 
     /**
      * Serializes a heartbeat message into a packet to be sent, and returns the byte array.
-     * @param heartbeat The heartbeat message to serialize.
+     * @param heartBeat The heartbeat message to serialize.
      * @return Byte array containing the next heartbeat message.
+     * @throws InvalidMessageException Thrown if the message cannot be encoded.
      */
-    private byte[] parseHeartbeat(Heartbeat heartbeat) {
+    private byte[] parseHeartbeat(HeartBeat heartBeat) throws InvalidMessageException {
 
         //Serializes the heartbeat message.
-        byte[] heartbeatMessage = RaceVisionByteEncoder.heartBeat(heartbeat);
+        byte[] heartbeatMessage = RaceVisionByteEncoder.encode(heartBeat);
 
         //Places the serialized message in a packet.
         BinaryMessageEncoder binaryMessageEncoder = new BinaryMessageEncoder(
@@ -213,7 +211,15 @@ public class MockOutput implements Runnable
     public void sendHeartBeat() throws IOException {
         //Sends a heartbeat every so often.
         if (timeSinceHeartbeat() >= heartbeatPeriod) {
-            outToVisualiser.write(parseHeartbeat(createHeartbeatMessage()));
+
+            HeartBeat heartBeat = createHeartbeatMessage();
+
+            try {
+                outToVisualiser.write(parseHeartbeat(heartBeat));
+            } catch (InvalidMessageException e) {
+                Logger.getGlobal().log(Level.WARNING, "Could not encode HeartBeat: " + heartBeat, e);
+            }
+
             lastHeartbeatTime = System.currentTimeMillis();
         }
     }

racevisionGame/src/main/java/network/BinaryMessageDecoder.java

@@ -133,9 +133,8 @@ public class BinaryMessageDecoder {
         switch(mType) {
             case HEARTBEAT:
                 //System.out.println("Decoding HeartBeat Message!");
-                //TODO maybe use HeartbeatDecoder.decode(message).
-                //TODO also, decoders for each message type should encapsulate the constructing of the object. E.g., return HeartbeatDecoder.decode(message);.
-                return new Heartbeat(bytesToLong(messageBody));
+                HeartBeatDecoder heartBeatDecoder = new HeartBeatDecoder(messageBody);
+                return heartBeatDecoder.getMessage();
 
             case RACESTATUS:
                 //System.out.println("Race Status Message");

racevisionGame/src/main/java/network/MessageDecoders/HeartBeatDecoder.java

@@ -0,0 +1,53 @@
+package network.MessageDecoders;
+
+import network.Messages.Enums.BoatActionEnum;
+import network.Messages.HeartBeat;
+
+import static network.Utils.ByteConverter.bytesToLong;
+
+/**
+ * Decodes {@link network.Messages.HeartBeat} messages.
+ */
+public class HeartBeatDecoder {
+
+    /**
+     * The encoded message.
+     */
+    private byte[] encodedMessage;
+
+    /**
+     * The decoded message.
+     */
+    private HeartBeat message;
+
+
+
+    /**
+     * Constructs a decoder to decode a given message.
+     * @param encodedMessage The message to decode.
+     */
+    public HeartBeatDecoder(byte[] encodedMessage) {
+        this.encodedMessage = encodedMessage;
+
+        decode();
+    }
+
+
+    /**
+     * Decodes the contained message.
+     */
+    private void decode() {
+
+        message = new HeartBeat(bytesToLong(encodedMessage));
+    }
+
+
+    /**
+     * Returns the decoded message.
+     * @return The decoded message.
+     */
+    public HeartBeat getMessage() {
+        return message;
+    }
+
+}

racevisionGame/src/main/java/network/MessageEncoders/EncoderFactory.java

@@ -29,6 +29,8 @@ public class EncoderFactory {
 
         switch (type) {
 
+            case HEARTBEAT: return new HeartBeatEncoder();
+
             case BOATLOCATION: return new BoatLocationEncoder();
 
             case REQUEST_TO_JOIN: return new RequestToJoinEncoder();

racevisionGame/src/main/java/network/MessageEncoders/HeartBeatEncoder.java

@@ -0,0 +1,40 @@
+package network.MessageEncoders;
+
+
+import network.Messages.AC35Data;
+import network.Messages.HeartBeat;
+
+import java.nio.ByteBuffer;
+
+import static network.Utils.ByteConverter.intToBytes;
+import static network.Utils.ByteConverter.longToBytes;
+
+/**
+ * This encoder can encode a {@link HeartBeat} message.
+ */
+public class HeartBeatEncoder implements MessageEncoder {
+
+
+    /**
+     * Constructor.
+     */
+    public HeartBeatEncoder() {
+    }
+
+
+    @Override
+    public byte[] encode(AC35Data message) {
+
+        //Downcast.
+        HeartBeat heartbeat = (HeartBeat) message;
+
+        //Message is 4 bytes.
+        ByteBuffer heartBeat = ByteBuffer.allocate(4);
+        heartBeat.put(longToBytes(heartbeat.getSequenceNumber(), 4));
+
+        byte[] result = heartBeat.array();
+
+        return result;
+
+    }
+}

racevisionGame/src/main/java/network/MessageEncoders/RaceVisionByteEncoder.java

@@ -19,20 +19,7 @@ import java.util.List;
  */
 public class RaceVisionByteEncoder {
 
-    /**
-     * Serializes a heartbeat message.
-     * @param heartbeat Heartbeat message.
-     * @return Serialized message.
-     */
-    public static byte[] heartBeat(Heartbeat heartbeat) {
-
-        ByteBuffer heartBeat = ByteBuffer.allocate(4);
-        heartBeat.put(longToBytes(heartbeat.getSequenceNumber(), 4));
 
-        byte[] result = heartBeat.array();
-
-        return result;
-    }
 
     /**
      * Serializes a RaceStatus message.

racevisionGame/src/main/java/network/Messages/HeartBeat.java

@@ -6,7 +6,7 @@ import network.Messages.Enums.MessageType;
 /**
  * Represents a Heartbeat message.
  */
-public class Heartbeat extends AC35Data {
+public class HeartBeat extends AC35Data {
 
     /**
      * Sequence number of the heartbeat.
@@ -17,7 +17,7 @@ public class Heartbeat extends AC35Data {
      * Ctor.
      * @param sequenceNumber Sequence number of the heartbeat.
      */
-    public Heartbeat(long sequenceNumber) {
+    public HeartBeat(long sequenceNumber) {
         super(MessageType.HEARTBEAT);
         this.sequenceNumber = sequenceNumber;
     }

racevisionGame/src/main/java/visualiser/app/VisualiserInput.java

@@ -1,26 +1,13 @@
 package visualiser.app;
-import javafx.application.Platform;
 import network.BinaryMessageDecoder;
 import network.Exceptions.InvalidMessageException;
 import network.Messages.*;
-import org.xml.sax.SAXException;
-import shared.dataInput.BoatXMLReader;
-import shared.dataInput.RaceXMLReader;
-import shared.dataInput.RegattaXMLReader;
-import shared.exceptions.InvalidBoatDataException;
-import shared.exceptions.InvalidRaceDataException;
-import shared.exceptions.InvalidRegattaDataException;
-import shared.exceptions.XMLReaderException;
-
-import javax.xml.parsers.ParserConfigurationException;
+
 import java.io.DataInputStream;
 import java.io.IOException;
 import java.net.Socket;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.concurrent.ArrayBlockingQueue;
 
 import static network.Utils.ByteConverter.bytesToShort;
 
@@ -213,12 +200,12 @@ public class VisualiserInput implements Runnable {
 
                 //Heartbeat.
                 case HEARTBEAT: {
-                    Heartbeat heartbeat = (Heartbeat) message;
+                    HeartBeat heartBeat = (HeartBeat) message;
 
                     //Check that the heartbeat number is greater than the previous value, and then set the last heartbeat time.
-                    if (heartbeat.getSequenceNumber() > this.lastHeartbeatSequenceNum) {
+                    if (heartBeat.getSequenceNumber() > this.lastHeartbeatSequenceNum) {
                         lastHeartbeatTime = System.currentTimeMillis();
-                        lastHeartbeatSequenceNum = heartbeat.getSequenceNumber();
+                        lastHeartbeatSequenceNum = heartBeat.getSequenceNumber();
                         //System.out.println("HeartBeat Message! " + lastHeartbeatSequenceNum);
                     }
 

racevisionGame/src/test/java/network/MessageDecoders/HeartBeatDecoderTest.java

@@ -0,0 +1,74 @@
+package network.MessageDecoders;
+
+import network.Exceptions.InvalidMessageException;
+import network.MessageEncoders.RaceVisionByteEncoder;
+import network.Messages.BoatAction;
+import network.Messages.Enums.BoatActionEnum;
+import network.Messages.HeartBeat;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+
+/**
+ * Test for the HeartBeat encoder and decoder
+ */
+public class HeartBeatDecoderTest {
+
+
+    /**
+     * Encodes and decodes a given message.
+     * @param message Message to encode/decode.
+     * @return The decoded message.
+     */
+    private HeartBeat encodeDecodeMessage(HeartBeat message) throws InvalidMessageException {
+
+        //Encode.
+        byte [] testEncodedMessage = RaceVisionByteEncoder.encode(message);
+
+        //Decode.
+        HeartBeatDecoder testDecoder = new HeartBeatDecoder(testEncodedMessage);
+        HeartBeat decodedMessage = testDecoder.getMessage();
+
+        return decodedMessage;
+    }
+
+
+    /**
+     * Tests if a heartbeat message with a given sequence number can be encoded and decoded correctly.
+     * @param sequenceNumber The sequenceNumber to use.
+     */
+    private void heartBeatTest(long sequenceNumber) throws Exception {
+
+        //Prepare message.
+        HeartBeat beforeMessage = new HeartBeat(sequenceNumber);
+
+
+        //Encode/decode it.
+        HeartBeat afterMessage = encodeDecodeMessage(beforeMessage);
+
+
+        //Compare.
+        assertEquals(beforeMessage.getSequenceNumber(), afterMessage.getSequenceNumber());
+
+    }
+
+
+    /**
+     * Tests if a heartbeat message with a sequence number of zero can be encoded and decoded correctly.
+     */
+    @Test
+    public void heartBeatZeroTest() throws Exception {
+        heartBeatTest(0);
+    }
+
+    /**
+     * Tests if a heartbeat message with a sequence number of 1234512 can be encoded and decoded correctly.
+     */
+    @Test
+    public void heartBeatNonZeroTest() throws Exception {
+        heartBeatTest(1234512);
+    }
+
+
+}