Edit ServletResponse body inside ZuulFilter

DummyFilter,java

package com.dummy.dummydata.filter;

import com.dummy.dummydata.pojo.*;
import com.google.gson.Gson;
import com.netflix.servo.jsr166e.ThreadLocalRandom;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import org.springframework.stereotype.Component;
import org.springframework.util.StreamUtils;

import javax.annotation.Nonnull;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.nio.charset.Charset;
import java.util.*;
import java.util.logging.Logger;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.POST_TYPE;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SEND_RESPONSE_FILTER_ORDER;

@Component
//Can be any filter
public class DummyFilter extends ZuulFilter {

    Logger logger = Logger.getLogger(getClass().getName());

    @Override
    public String filterType() {
        return POST_TYPE;
    }

    @Override
    public int filterOrder() {
        return SEND_RESPONSE_FILTER_ORDER - 1;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {

        RequestContext context = RequestContext.getCurrentContext();

        HttpServletRequest servletRequest = context.getRequest();
        HttpServletResponse servletResponse = context.getResponse();
        
        //Check if response is gzipped
        boolean stream = context.getResponseGZipped();

        if (stream) {
        InputStream inputStream = context.getResponseDataStream();
            try {
                GZIPInputStream gzipInputStream = new GZIPInputStream(inputStream);
                String body = StreamUtils.copyToString(gzipInputStream, Charset.defaultCharset());
                
                //Convert from json to POJO
                RandomPojo randomPojo = new Gson().fromJson(body, RandomPojo.class);
                
                //Do some editing here.
                // eg. randomPojo.setName("randomName");
                
                //Convert back to json
                String gsonResponse = new Gson().toJson(randomPojo);
                
                //Recompress json
                InputStream responseInputStream = new ByteArrayInputStream(gsonResponse.getBytes());
                InputStream gzippedResponse = compress(responseInputStream);

                context.setResponseDataStream(gzippedResponse);
                context.setResponseGZipped(true);

            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return null;
    }

    public InputStream compress(@Nonnull final InputStream inputStream) {
        InputStream zipInputStream = null;
        try {
            ByteArrayOutputStream bytesOutput = new ByteArrayOutputStream();
            GZIPOutputStream gzipOutput = new GZIPOutputStream(bytesOutput);

            try {
                byte[] buffer = new byte[10240];
                for (int length = 0; (length = inputStream.read(buffer)) != -1; ) {
                    gzipOutput.write(buffer, 0, length);
                }
            } finally {
                try {
                    inputStream.close();
                } catch (IOException ignore) {
                }
                try {
                    gzipOutput.close();
                } catch (IOException ignore) {
                }
            }

            zipInputStream = new ByteArrayInputStream(bytesOutput.toByteArray());
        } catch (IOException e) {
            e.printStackTrace();
        }

        return zipInputStream;
    }
}