Concatenate byte arrays

Question

I have a Socket that is sending data accross a connection. I want to keep reading more data into an array. Is there a way to add more data into an array, or do I have to create a new one every time.
I'd like to do something like this:
byte[] b = new byte[10];
istrm.read( b2);
b += b2; <----- I know this doesn't work
I have been writing it like this:
InputStream istrm = sock.getInputStream();
byte[] b = new byte[ istrm.available()];
istrtrm.read( b);
but I don't know if that gets all of the data. If it blocks for a while, does that mean more data will come down the stream? I just want to make sure the data all gets there and put into 1 byte array.
Thanks in advance.

Answer 1

You cannot alter the size of an array object. You must allocate another array and copy the contents from the original. A better way would probably be to have a list of arrays, keeping track of the total received. THen create a single array and copy the data from the smaller arrays. You could have this happen whenever the list length exceeds a chosen boundary to avoid having too many small array objects referenced in memory.
eg
byte[] b1 = new byte[100];
byte[] b2 = new byte[50];
List list = new LinkedList();
int totalSize = 0;
list.add(b1);
totalSize += b1.length();
list.add(b2);
totalSize += b2.length();
byte[] b = new byte[totalSize];
int currentPos = 0;
for(Iterator iterator = list.iterator(); iterator.hasNext(); )
byte[] temp = (byte[]) iterator.next();
for(int count = 0; count < temp.length; count++)
b[currentPos++] = temp[count];
or something like that... (untested)
Hope that helps...
Talden