Java Development

[tejaswini]

Hi,

I am compressing and decompressing data on Blackberry 8100 device using GZip algorithm.

I am using following code:

try {			GZIPOutputStream gCompress = null;			try {				ByteArrayOutputStream compressByte = new ByteArrayOutputStream();				gCompress = new GZIPOutputStream(compressByte,9);				gCompress.write(inputstring.getBytes());												//gCompress.flush();				compressedBytes = compressByte.toByteArray();				System.out.println("compressedBytes : "						+ new String(compressedBytes));				compressedString = new String(compressedBytes);							} catch (IOException ex) {				ex.printStackTrace();			}		} catch (Exception e) {			e.printStackTrace();		}

The server is not able to decompress data .

Please help.

Thanks a lot.

[RexDoug]

You probably have to explicitly state that the content is GZIP so that the server will recognize it and unzip the payload.

Try setting the "Content-Encoding" header to "gzip"

[peter_strange · Accepted solution]

I think you are doing a byte to String conversion which you should not be doing and which may be screwing up your data.  The output from a compression is not likely to be easily represented as Unicode characters and you actually want to transmit the bytes, so I think this is not needed.

Here is a reworked version of the sample in the API, which I believe to be inaccurate, anyway:  Give this a try and remember that you need to send the bytes, not the chars.

public static byte[] compress( byte[] data ) {    
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        GZIPOutputStream gzipStream = new GZIPOutputStream( baos, 
                                                            GZIPOutputStream.COMPRESSION_BEST, 
                                                            GZIPOutputStream.MAX_LOG2_WINDOW_LENGTH );
        gzipStream.write( data );
        gzipStream.close();
        return baos.toByteArray();
    }
    catch(IOException ioe) {
        return null;
    }
} 

[mihirpmehta]

Hi, using this i convert one audio file in to input stream and after compression the size of the return byte Array is actually more than what i give as parameter ...

any idea ?

[mihirpmehta]

How to write these Compressed data in files ... can anyone gice sample code for compressing a File ?