Optimize performance :Passing large JSON from Servlet to JSP - json

Question

I have to pass a json array consisting of json objects from the servlet to the jsp page. This data transfer slows down page responsiveness. Is there any way to optimize performance while passing large json from servlet to jsp.
code looks like:
request.setAttribute("jsonStringForDataTable", jsonArrayForDataTable);
response.setContentType("text/plain");
response.setContentLength(jsonArrayForDataTable.toString().getBytes().length);
ServletOutputStream out=response.getOutputStream();
out.print(jsonArrayForDataTable.toString().replace('_',' '));
out.close();
...
Any help is highly appreciated

Answer 1

You're using ajax, right? It's hard to tell since you're setting that request attribute, as if about to forward to a jsp, but then you're writing directly to the response. If this is ajax, you can compress the response with gzip if the client accepts it. You'll have to try it to know if it will speed things up in your situation. You'll be reducing the size of the response by a ratio that depends on the original content, but you'll be increasing the amount of processor work on the server (and on the client, which has to decompress the response).
ServletOutputStream out = response.getOutputStream();
response.setContentType("application/json");
String strVal = jsonArrayForDataTable.toString().replace('_',''));
if (request.getHeader("Accept-Encoding") != null && request.getHeader("Accept-Encoding").contains("gzip"))
{
ByteArrayOutputStream baos = new ByteArrayOutputStream(strVal.length());
GZipOutputStream gzip = new GZIPOutputStream(baos);
gzip.write(strVal.getBytes());
gzip.close();
response.setHeader("Content-Encoding", "gzip");
out.write(baos.toByteArray());
baos.close();
}
else
{
out.print(strVal);
}
On the client side, you have to be prepared for a gzipped response by setting the Accept-Encoding XMLHttpRequest header to gzip. The browser will decompress it into the json string.