Inflater/Deflater Question

Question

Hi
I was lookign into the java.util.zip package utilities - Inflator and Deflator apis and I am bit confused abt their usage - Lets take the scenario where I want to compress a byte[] of data - Ideally I would expect an API to like
public byte[] compress(byte[] dataToCompress)
Strangely enough the Deflator api does not have this - instead it has - setInput(byte[] dataToCompress) and then int deflate(byte[] buffer) - How on the world I will know the buffer size if I dont know what the compressed data size will be?? .
If anyone has really used Deflater - pls let me know how they have got around this problem. OR If there is any other better way to do that pls let me know.
TIA
Anamitra

Answer 1

Disclaimer: I have never used the Deflator class and this is meant to be a hand-waving example, it is not meant to be 'good' code. By no means should you use this code for anything important. You need to understand the class before you actually use it. I am just showing you the basic idea. From looking at the API there is clearly much more than this needed to use the class correctly. I haven't even tried to compile this.
Do something to the effect of:
ArrayList bufferList = new ArrayList;
byte[] input = getInput();
Deflator deflator = new Deflator();
int bytesReturned;
deflator.setInput(input);
do {
   byte[] buffer = new byte[1000]
   bytesReturned = deflator.deflate(buffer);
   bufferList.add(buffer);
} while (bytesReturned == 1000)