Find the size of the file inside a GZIP file

Question

Is there a way to find out the size of the original file which is inside a GZIP file in java?

As in, I have a file a.txt of 15 MB which has been GZipped to a.gz of s

Answer 1

public class ReadStream {

    public static void main(String[] args) {
        try {
            RandomAccessFile raf = new RandomAccessFile(new File("D:/temp/temp.gz"), "r");
            try {
                raf.seek(raf.length() - 4);

                int b4 = raf.read();
                int b3 = raf.read();
                int b2 = raf.read();
                int b1 = raf.read();
                int val = (b1 << 24) | (b2 << 16) + (b3 << 8) + b4;

                System.out.println(val);

                raf.close();
            } catch (IOException ex) {
                Logger.getLogger(ReadStream.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(ReadStream.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}