Wicket 6 MyAppPageBuffer

package mywebapp;

import org.apache.wicket.Page;
import org.apache.wicket.ThreadContext;
import org.apache.wicket.core.request.handler.PageProvider;
import org.apache.wicket.core.request.handler.RenderPageRequestHandler;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.protocol.http.WebSession;
import org.apache.wicket.protocol.http.mock.MockHttpServletRequest;
import org.apache.wicket.protocol.http.mock.MockHttpServletResponse;
import org.apache.wicket.protocol.http.mock.MockHttpSession;
import org.apache.wicket.protocol.http.servlet.ServletWebRequest;
import org.apache.wicket.protocol.http.servlet.ServletWebResponse;
import org.apache.wicket.request.Url;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.cycle.RequestCycleContext;
import org.apache.wicket.request.handler.render.PageRenderer;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletContext;
import java.util.ArrayList;
import java.util.Arrays;


/**

 */
public class MyAppPageBuffer {

    private static final Logger LOGGER = LoggerFactory.getLogger(MyAppPageBuffer.class);

    private String buffer;

    WebApplication myApp;




    public MyAppPageBuffer (WebApplication myApp) {
        this.myApp = myApp;
    }


    public String getBuffer() {
        return buffer;
    }

    public boolean isEmpty() {
        return buffer == null || buffer.isEmpty();
    }





    public synchronized String renderPage() {
        LOGGER.debug("RenderPagex init");

        ThreadContext.setApplication(null);
        ThreadContext.setSession(null);
        ThreadContext.setRequestCycle(null);

        // Context data
        String contextPath = "";
        String filterPath = "";

        // Url of page to render
        Url url = new Url(Arrays.asList("mypage"), new ArrayList<Url.QueryParameter>());
        String filterPrefix = contextPath + filterPath;

        WebApplication webApplication = isdefeWebApp;
        ServletContext context = isdefeWebApp.getServletContext();

        // Page to reder
        final Class<? extends Page> pageClass = MyPage.class;
        PageParameters parameters = new PageParameters();


        MockHttpSession servletSession = new MockHttpSession(context);
        servletSession.setTemporary(true);

        MockHttpServletRequest mockServletRequest = new MockHttpServletRequest(isdefeWebApp, servletSession, context);
        MockHttpServletResponse mockServletResponse = new MockHttpServletResponse(mockServletRequest);

        //initialize request and response
        mockServletRequest.initialize();
        mockServletResponse.initialize();


        // Wicket servlet and response
        ServletWebRequest webRequest = new ServletWebRequest(mockServletRequest, filterPrefix, url);
        ServletWebResponse webResponse = new ServletWebResponse(webRequest, mockServletResponse);
        WebSession webSession = new WebSession(webRequest);

        // Create request cycle
        RequestCycleContext requestCycleContext = new RequestCycleContext(webRequest, webResponse, webApplication.getRootRequestMapper(), webApplication.getExceptionMapperProvider().get());

        RequestCycle requestCycle = new RequestCycle(requestCycleContext);

        // Se to thread
        ThreadContext.setApplication(webApplication);
        ThreadContext.setSession(webSession);
        ThreadContext.setRequestCycle(requestCycle);

        final RenderPageRequestHandler handler = new RenderPageRequestHandler(new PageProvider(pageClass, parameters), RenderPageRequestHandler.RedirectPolicy.NEVER_REDIRECT);
        final PageRenderer pageRenderer = webApplication.getPageRendererProvider().get(handler);


        try {
            requestCycle.scheduleRequestHandlerAfterCurrent(null);
            requestCycle.getUrlRenderer().setBaseUrl(webRequest.getUrl());
            pageRenderer.respond(requestCycle);
            buffer = mockServletResponse.getDocument();
        } catch (Exception e) {
            buffer = null;
            LOGGER.error("Error renderPage", e);
        } finally {
            requestCycle.detach();
            ThreadContext.setApplication(null);
            ThreadContext.setSession(null);
            ThreadContext.setRequestCycle(null);
        }
        if (buffer != null && buffer.isEmpty()) buffer = null;
        LOGGER.debug("RenderPage buffer " + (buffer!= null?(""+buffer.length()):"null"));
        return buffer;
    }


}