Create Framework for raw data or Binary read and write

I am working on one project in which data has to read in binary format but one can put into a structure format. In java Structure is not available. I have send the data in byte array. It also has some structure.

For Example

Packet

int length 
int sequence no
MessageData

MessageData MessageHeader MessageBody

MessageHeader int data1 long data2 char[] data3//2bytes char[] data4//3 bytes

Same for MessageBody

But data should be packed in byte array.

One can do in CPP as

#pragma(2) //for word alignment

struct Packet{
    int length 
    int sequence no
    MessageData msgdata

}

I have to implement in java.

for reading data I am using Preon library

But for writing data I am still using normal method for packaging data in byte array with help of 开发者_高级运维some function Anybody have work on same kind project or have better idea

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The current codebase does contain some bytes for writing data, however, it's not completed yet. Having said that, it might work for your current case:

Codec<Packet> codec = Codecs.create(Packet.class);
Packet packet = ...;
OutputStream out = ...;
codecs.encode(packet, codec, out);