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The message encoders and decoders now catch exceptions, and throw InvalidMessageException.

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Removed the big switch statement from BinaryMessageDecoder - it now uses the decoder factory instead.
issue #35 #36
#story[1095]
This commit is contained in:
fjc40
2017-08-06 22:25:43 +12:00
parent 9c64b678e3
commit 134586f407
34 changed files with 879 additions and 719 deletions
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racevisionGame/src/main/java/network/BinaryMessageDecoder.java
+55 -96
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@@ -17,42 +17,71 @@ import java.util.zip.CRC32;
*/
public class BinaryMessageDecoder {
///Length of the header.
/**
* Length of the header.
*/
private static final int headerLength = 15;
///Length of the CRC.
private static final int CRCLength = 4;//TODO these should probably be static defined somewhere else to be shared.
/**
* Length of the CRC.
*/
private static final int CRCLength = 4;
///The value the first sync byte should have.
/**
* The value the first sync byte should have.
*/
private static final byte syncByte1 = (byte) 0x47;
//The value the second sync byte should have.
/**
* The value the second sync byte should have.
*/
private static final byte syncByte2 = (byte) 0x83;
///The full message.
/**
* The full message.
*/
private byte[] fullMessage;
///The messageHeader.
/**
* The messageHeader.
*/
private byte[] messageHeader;
///The messageBody.
/**
* The messageBody.
*/
private byte[] messageBody;
///The sync bytes from the header..
/**
* The sync bytes from the header.
*/
private byte headerSync1;
private byte headerSync2;
///The message type from the header.
/**
* The message type from the header.
*/
private byte headerMessageType;
///The timestamp from the header.
/**
* The timestamp from the header.
*/
private long headerTimeStamp;
///The source ID from the header.
/**
* The source ID from the header.
*/
private int headerSourceID;
///The message body length from the header.
/**
* The message body length from the header.
*/
private int messageBodyLength;
///CRC value read from message header.
/**
* CRC value read from message header.
*/
private long messageCRCValue;
///Calculated CRC value from message.
/**
* Calculated CRC value from message.
*/
private long calculatedCRCValue;
@@ -114,104 +143,34 @@ public class BinaryMessageDecoder {
//Check the message body length.
throw new InvalidMessageException("MessageBody length in header does not equal the messageBody length. MessageBody length in header is: " + messageBodyLength + ", should be: " + messageBody.length);
}else if (headerSync1 != syncByte1) {
} else if (headerSync1 != syncByte1) {
//Check the first sync byte.
throw new InvalidMessageException("Sync byte 1 is wrong. Sync byte is: " + headerSync1 + ", should be: " + syncByte1);
}else if (headerSync2 != syncByte2) {
} else if (headerSync2 != syncByte2) {
//Check the second sync byte.
throw new InvalidMessageException("Sync byte 2 is wrong. Sync byte is: " + headerSync2 + ", should be: " + syncByte2);
}else if (calculatedCRCValue != messageCRCValue) {
} else if (calculatedCRCValue != messageCRCValue) {
//Check the CRC value.
throw new InvalidMessageException("CRC value is wrong. The calculated value is: " + calculatedCRCValue + ", should be: " + messageCRCValue);
}
//Now we create the message object based on what is actually in the message body.
MessageType mType = MessageType.fromByte(headerMessageType);
MessageType messageType = MessageType.fromByte(headerMessageType);
/*MessageDecoder decoder = null;
MessageDecoder decoder = null;
try {
decoder = DecoderFactory.create(mType);
decoder = DecoderFactory.create(messageType);
} catch (InvalidMessageTypeException e) {
throw new InvalidMessageException("Could not create decoder for MessageType: " + mType, e);
}
return decoder.decode(messageBody);*/
switch(mType) {
case HEARTBEAT:
//System.out.println("Decoding HeartBeat Message!");
HeartBeatDecoder heartBeatDecoder = new HeartBeatDecoder();
return heartBeatDecoder.decode(messageBody);
case RACESTATUS:
//System.out.println("Race Status Message");
RaceStatusDecoder rsdecoder = new RaceStatusDecoder();
return rsdecoder.decode(messageBody);
case DISPLAYTEXTMESSAGE:
//System.out.println("Display Text Message");
//No decoder for this.
//throw new InvalidMessageException("Cannot decode DISPLAYTEXTMESSAGE - no decoder.");
case XMLMESSAGE:
//System.out.println("XML Message!");
XMLMessageDecoder xmdecoder = new XMLMessageDecoder();
return xmdecoder.decode(messageBody);
case RACESTARTSTATUS:
//System.out.println("Race Start Status Message");
RaceStartStatusDecoder rssDecoder = new RaceStartStatusDecoder();
return rssDecoder.decode(messageBody);
case YACHTEVENTCODE:
//System.out.println("Yacht Action Code!");
//No decoder for this.
//throw new InvalidMessageException("Cannot decode YACHTEVENTCODE - no decoder.");
case YACHTACTIONCODE:
//System.out.println("Yacht Action Code!");
//No decoder for this.
//throw new InvalidMessageException("Cannot decode YACHTACTIONCODE - no decoder.");
case CHATTERTEXT:
//System.out.println("Chatter Text Message!");
//No decoder for this.
//throw new InvalidMessageException("Cannot decode CHATTERTEXT - no decoder.");
case BOATLOCATION:
//System.out.println("Boat Location Message!");
BoatLocationDecoder blDecoder = new BoatLocationDecoder();
return blDecoder.decode(messageBody);
case MARKROUNDING:
//System.out.println("Mark Rounding Message!");
MarkRoundingDecoder mrDecoder = new MarkRoundingDecoder();
return mrDecoder.decode(messageBody);
case COURSEWIND:
//System.out.println("Course Wind Message!");
CourseWindsDecoder cwDecoder = new CourseWindsDecoder();
return cwDecoder.decode(messageBody);
case AVGWIND:
//System.out.println("Average Wind Message!");
AverageWindDecoder awDecoder = new AverageWindDecoder();
return awDecoder.decode(messageBody);
case BOATACTION:
BoatActionDecoder baDecoder = new BoatActionDecoder();
return baDecoder.decode(messageBody);
default:
//System.out.println("Broken Message!");
//throw new InvalidMessageException("Broken message! Did not recognise message type: " + headerMessageType + ".");
return null;
throw new InvalidMessageException("Could not create decoder for MessageType: " + messageType, e);
}
return decoder.decode(messageBody);
}