Netty ByteBuf First Time Implementation

Question

My Plan is to have a message protocol as outlined below:

• MessageLength : integer with total message length
• MessageID : integer with auto incrementing identifier
• MessageType : integer ( enum ) with the type of message
• Payload : byte[] with the Payload of the message (Serialised POJO)

At the moment I just am looking at making sure I create the ByteBuf in the correct and optimal way. At this stage I have the following:

io.netty.buffer.ByteBuf buf = Unpooled.buffer();

// Test Data Class
TestData test = new TestData("FirstName", "LastName", 40);

// Convert to Bytes is method to return the Byte Array (Serialised POJO)
byte[] payload = convertToBytes(test);

// Write 1 simulating MessageID 1
buf.writeInt(1);

// Write 2 simulating MessageType of 2
buf.writeInt(2);

// Write The Payload data<BR>
buf.writeBytes(payload);

The goal would be to them pass on to a LengthFieldPrepender and up the pipeline.

Is this the right way to create the ByteBuf ? Or is there a better way?

Answer 1

You should use the allocator to create the ByteBuf if possible as this may give you a pooled ByteBuf (depending on the configuration).

Something like:

Channel channel = ...
channel.alloc().buffer(expectedSize)

Also note that I passed in the expected size of the ByteBuf as this will ensure we not need to expand it later on when you fill it.