Created AC35 Streaming server

- Sends heartbeat messages every 5 seconds
- Sends XML at beginning

Tags: #story[29]

src/main/java/seng302/server/messages/Header.java

@@ -0,0 +1,71 @@
+package seng302.server.messages;
+
+import java.nio.ByteBuffer;
+
+public class Header {
+    // From API spec
+    private final int syncByte1 = 0x47;
+    private final int syncByte2 = 0x83;
+
+    private MessageType messageType;
+    private int timeStamp;
+    private int sourceId;
+    private short messageLength;
+    private static final int MESSAGE_LEN = 15;
+
+    /**
+     * Message Header from section 3.2 of the AC35 Streaming
+     * Data spec
+     * @param messageType The type of the message following this header
+     * @param sourceId The message source (as defined in the spec)
+     * @param messageLength The length of the message following this header
+     */
+    public Header(MessageType messageType, int sourceId, Short messageLength){
+        this.messageType = messageType;
+        this.sourceId = sourceId;
+        this.messageLength = messageLength;
+        timeStamp = (int) (System.currentTimeMillis() / 1000L);
+    }
+
+    /**
+     * @return a ByteBuffer containing the message header
+     */
+    public ByteBuffer getByteBuffer(){
+        ByteBuffer buff = ByteBuffer.allocate(15);
+
+        // Sync Byte 1, 1 byte
+        buff.put(ByteBuffer.allocate(1).put((byte)syncByte1).array());
+        buff.position(1);
+
+        // Sync Byte 2, 1 byte
+        buff.put(ByteBuffer.allocate(1).put((byte)syncByte2).array());
+        buff.position(2);
+
+        // Message Type, 1 byte
+        buff.put(ByteBuffer.allocate(1).put((byte)messageType.getCode()).array());
+        buff.position(3);
+
+        // Timestamp, 6 bytes
+        int x = ((int) Integer.toUnsignedLong(6));
+        buff.put(ByteBuffer.allocate(6).putInt(timeStamp).array());
+        buff.position(9);
+
+        // Source ID, 4 bytes
+        buff.put(ByteBuffer.allocate(4).putInt(sourceId).array());
+        buff.position(13);
+
+        // Message Length, 2 bytes
+        buff.put(ByteBuffer.allocate(2).putShort(messageLength).array());
+        buff.position(15);
+
+        return buff;
+    }
+
+    /**
+     * Returns the size of this message
+     * @return the size of the message
+     */
+    public static Integer getSize(){
+        return MESSAGE_LEN;
+    }
+}