Reading and uncompressing gzipped file from an https site finishes prematurely

Question

What I am trying to do is to download a gzipped file and uncompress it on the fly, from an https site. For that, I have the following code. While the code does download and unzip on the fly, it does not do it for the whole file. The condition (readLine = br.readLine()) != null becomes false much before the end of the input is reached that is. What could be the problem? Any other way to do this, or solve it?

import java.net.*;
import java.io.*;
import javax.net.ssl.*; 
import java.util.zip.GZIPInputStream;
import java.nio.charset.StandardCharsets;
......

BufferedReader br = null;
PrintWriter pw = null;

try 
{       
    URL myurl = new URL(
 "https://dnanexus-rnd.s3.amazonaws.com/NA12878-xten/reads/NA12878D_HiSeqX_R1.fastq.gz");
    HttpsURLConnection con = (HttpsURLConnection)myurl.openConnection();
    GZIPInputStream gzis = new GZIPInputStream(con.getInputStream());
    br = new BufferedReader(new InputStreamReader(gzis, StandardCharsets.UTF_8));

    pw = new PrintWriter(new File("NA12878D_HiSeqX_R1.fastq"));
    String readLine;
    while ((readLine = br.readLine()) != null)
        pw.println(readLine);
} 
finally 
{
    pw.close();
    br.close();
}

Note that if I just download the gzipped file itself, that is, not also uncompress it, it downloads fine. So, it does not look like there is any problem with the server itself. Moreover, I don't get any exceptions.