java data structure for growing data?

[nooneinparticular314159]

I need to transmit some information over a network. The data is a
message of arbitrary length. I can include information in the header
about the size of the message. But I need a java object to store the
data in that can grow as needed to store more information, but can also
be made exactly the size of the message once I know how big the message
is. ie. If my message is 52342 bytes, I want to store an int saying
it is 52342 bytes, followed by exactly 52342 bytes of data. Is there
an object that is appropriate for this?

Thanks!

 

[Alan Krueger]

I need to transmit some information over a network. The data is a
message of arbitrary length. I can include information in the header
about the size of the message. But I need a java object to store the
data in that can grow as needed to store more information, but can also
be made exactly the size of the message once I know how big the message
is. ie. If my message is 52342 bytes, I want to store an int saying
it is 52342 bytes, followed by exactly 52342 bytes of data. Is there
an object that is appropriate for this?

ByteArrayOutputStream out = new ByteArrayOutputStream();
// ...write stuff to out...
int size = out.size();
networkStream.write( out.toByteArray() );

 

[Roedy Green]

I need to transmit some information over a network. The data is a
message of arbitrary length. I can include information in the header
about the size of the message. But I need a java object to store the
data in that can grow as needed to store more information, but can also
be made exactly the size of the message once I know how big the message
is. ie. If my message is 52342 bytes, I want to store an int saying
it is 52342 bytes, followed by exactly 52342 bytes of data. Is there
an object that is appropriate for this?

You serialise the object to a ByteArrayStream then to a byte[].

See http://mindprod.com/applets/fileio.html for how to create it and
how to ship it over a socket.