DumpFilter

.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.util.FileCopyUtils;

@Component
public class DumpFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
            throws IOException, ServletException {
        // TODO Auto-generated method stub
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;

        HttpServletResponse response = (HttpServletResponse) servletResponse;
        System.out.println(httpRequest.getRequestURI());
        System.out.println(httpRequest.getRequestURI().toLowerCase().endsWith("/v2/api-docs"));
        ByteArrayPrinter pw = new ByteArrayPrinter();
        // here i create a response wrapper
        HttpServletResponse wrappedResp = new HttpServletResponseWrapper(response) {
            @Override
            public PrintWriter getWriter() {
                return pw.getWriter();
            }

            @Override
            public ServletOutputStream getOutputStream() {
                return pw.getStream();
            }

        };
        System.out.println("before chaingin");
        // i get the response data from the stream
        chain.doFilter(httpRequest, wrappedResp);
        byte[] bytes = pw.toByteArray();
        String respBody = new String(bytes);
        System.out.println("in if" + respBody);
        if (httpRequest.getParameter("group") != null) {

            // RequestWrapper wrappedRequest = new RequestWrapper(httpRequest);

            // wrappedRequest.addHeader("Accept", MediaType.APPLICATION_JSON_VALUE);
            // FileCopyUtils.copy(
            // new FileInputStream(new File(System.getProperty("user.dir") + "/static/swagger.json")),
            // response.getOutputStream());

            byte[] newByte = pw.toByteArray();
            String newString = new String(newByte);
            System.out.println("new string:" + newString);
            // i make a modification in the stream
            String s = newString.replaceAll("basePath", "Vijayy");
            System.out.println("printing s" + s);

            // here i try to write to a file with the modification
            try (FileOutputStream fos = new FileOutputStream(
                    new File(System.getProperty("user.dir") + "/static/openAPI.json"))) {
                System.out.println("comin in if");
                fos.write(s.getBytes());
                // after writing it I read the file data and output it
                // i actually modify the response data with just "basePath" as "Vijay" dyanmically.
                // so in the actual openAPI spec I can do the modification of <Json> element
                // this works actually. I will run it now

                FileCopyUtils.copy(
                        new FileInputStream(new File(System.getProperty("user.dir") + "/static/openAPI.json")),
                        response.getOutputStream());

            } catch (FileNotFoundException ex) {
                ex.printStackTrace();
            }
            // FileCopyUtils.copy(, out);

            // IOUtils.copy(new ByteArrayInputStream(newString.getBytes()), response.getOutputStream());

        } else {
            chain.doFilter(httpRequest, wrappedResp);
            response.setHeader("Content-Type", MediaType.APPLICATION_JSON_VALUE);
            response.setContentLength(respBody.length());
            response.getOutputStream().write(respBody.getBytes());
        }
        // List<String> s13 = Stream.of(respBody).filter((s1) -> s1.contains("<Json>"))
        // .map((sample) -> Arrays.asList(sample.split(" ")))
        // .flatMap((listString) -> {
        // StringBuffer sb = new StringBuffer();
        // listString.forEach(item -> {
        //
        // sb.append(item);
        //
        // });
        // return Stream.of(sb.toString().trim().replace("<Json>", "").replace("</Json>", ""));
        // }).collect(Collectors.toList());
        // s13.forEach(item -> System.out.println("items :" + item));
        // String s14 = String.join("", s13);

        return;
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // TODO Auto-generated method stub

    }

    @Override
    public void destroy() {
        // TODO Auto-generated method stub

    }

}