Manipulate request body with Zuul - netflix-zuul

Question

We're using Zuul as edge server. I want to write a filter that replaces the multipart/form-data from an inbound request with an entity which has the first application/json part of that request.
So that for example the request with multiparts:
[multipart/form-data]
[Part 1] << Application/JSON (name="info")
[Part 2] << Binary (name="file")
is translated into:
[application/json]
[Contents of Part 1]
Would this be possible with Zuul filters, and what type of filter should I use?

Answer 1

I recently had to peek into the body to figure out how to route messages that were incoming. The code below shows how you can pull the body from the request and transform it into a JSON object. That might get you started.
public class ActivateServicePreFilter extends ZuulFilter {
#Override
public String filterType() {
return PRE_TYPE;
}
#Override
public int filterOrder() {
return 4;
}
#Override
public boolean shouldFilter() {
HttpServletRequest request = RequestContext.getCurrentContext().getRequest();
return "POST".equals(request.getMethod()) && request.getRequestURI().contains("uri-string");
}
#Override
public Object run() {
HttpServletRequest request = RequestContext.getCurrentContext().getRequest();
StringBuffer jb = new StringBuffer();
String line = null;
try {
BufferedReader reader = request.getReader();
while ((line = reader.readLine()) != null)
jb.append(line);
} catch (Exception e) { /*report an error*/ }
try {
JSONObject jsonObject = new JSONObject(jb.toString());
String jsonField = jsonObject.getString("jsonFieldKey");
System.out.println(jsonField);
} catch (JSONException e) {
// crash and burn
}
return null;
}