Added CRC to Encoder

- Added CRC to Message Encoder
#story[778]

src/main/java/seng302/Networking/BinaryMesageEncoder.java

@@ -1,8 +1,10 @@
 package seng302.Networking;
 
+
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Arrays;
+import java.util.zip.CRC32;
 
 /**
  * Created by hba56 on 21/04/17.
@@ -11,7 +13,7 @@ public class BinaryMesageEncoder {
     private byte[] fullMessage;
     private byte[] header;
     private byte[] message;
-    private byte[] crc;
+    //private byte[] crc;
 
     private byte headerSync1 = (byte)0x47;
     private byte headerSync2 = (byte)0x83;
@@ -46,8 +48,15 @@ public class BinaryMesageEncoder {
         tempMessageByteBuffer.put(this.header);
         tempMessageByteBuffer.put(this.message);
 
-        //todo fix crc, currently just some int
-        tempMessageByteBuffer.put(intToBytes(1));
+        CRC32 crc = new CRC32();
+        crc.reset();
+        byte[] messageAndHeader = new byte[this.header.length + this.message.length];
+        System.arraycopy(this.header, 0, messageAndHeader, 0, this.header.length);
+        System.arraycopy(this.message, 0, messageAndHeader, this.header.length, this.message.length);
+        crc.update(messageAndHeader);
+        //System.out.println(Arrays.toString(messageAndHeader));
+
+        tempMessageByteBuffer.put(intToBytes((int) crc.getValue()));
         this.fullMessage = tempMessageByteBuffer.array();