Not in GZIP format报错求助

[Oo风影我爱罗oO]

现在根据URLConnection访问时遇到了这样一个问题，运行程序时会偶尔报Not in GZIP format，这个问题不是经常出现，是偶尔会出现，而且没有规律。

代码如下：

public static Serializable sendRequest(String servlet_url, Serializable obj)  throws Exception  {
	URL url = new URL(servlet_url);
    
	HttpURLConnection con = (HttpURLConnection)url.openConnection();
    
	con.setDoInput(true);
	con.setDoOutput(true);
	con.setUseCaches(false);
	con.setRequestProperty("Content-Type", "application/octet-stream");

	writeZIPObject(con.getOutputStream(), obj);

	Serializable reply = null;
	reply = (Serializable)readZIPObject(con.getInputStream());

	con.disconnect();

	Serializable result = reply.getData();
	if (result instanceof Exception) {
		throw ((Exception)result);
	}

	...

  }

public static Serializable readZIPObject(InputStream in) throws IOException, ClassNotFoundException {
	BufferedInputStream buffer = new BufferedInputStream(in);
	GZIPInputStream gi = new GZIPInputStream(buffer);
	ObjectInputStream oi = new ObjectInputStream(gi);

	Serializable obj = (Serializable) oi.readObject();

	oi.close();
	gi.close();
	buffer.close();
	in.close();
	return obj;
}

public static void writeZIPObject(OutputStream out, Serializable obj) throws IOException {
	BufferedOutputStream buffer = new BufferedOutputStream(out);
	GZIPOutputStream go = new GZIPOutputStream(buffer);
	ObjectOutputStream oo = new ObjectOutputStream(go);

	oo.close();
	go.close();
	buffer.close();
	out.close();
}

现在在程序中报这样一个错：
java.io.IOException: Not in GZIP format
at java.util.zip.GZIPInputStream.readHeader(Unknown Source)
at java.util.zip.GZIPInputStream.<init>(Unknown Source)
at java.util.zip.GZIPInputStream.<init>(Unknown Source)
...

报错代码是GZIPInputStream gi = new GZIPInputStream(buffer);

我已经查了网上很多种解决方案可尝试后发现都没有解决，值得注意的是现在程序中传给servlet_url的是一个HTTPS的URL，以前为HTTP时貌似是没有问题的。

请教那位大神遇到过这种问题帮忙回答下

[huntor]

换HttpsURLConnection试试