org.ngrinder.infra.spring.Redirect404DispatcherServlet.java Source code

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Here is the source code for org.ngrinder.infra.spring.Redirect404DispatcherServlet.java

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/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.ngrinder.infra.spring;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonObject;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.util.UrlPathHelper;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * NGrinder specialized Servlet Dispatcher.
 * <p/>
 * The default DispatcherServlet returns 404 error when the corresponding Handler is not found.
 * Then 404 was redirected to corresponding error page using web.xml error_page setting..
 * <p/>
 * This does not work when the 404 error occurs in the SVN path. It should directly return the 404 to the client.
 * So this class checked the path first and redirect the error_404 page directly when the /svn/ path is not included in the request's path info
 */
public class Redirect404DispatcherServlet extends DispatcherServlet {

    private static final String JSON_SUCCESS = "success";
    private static final String JSON_CAUSE = "message";
    private static final UrlPathHelper urlPathHelper = new UrlPathHelper();
    private static Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().setPrettyPrinting()
            .create();

    /**
     * Redirect to error 404 when the /svn/ is not included in the path.
     *
     * @param request  current HTTP requests
     * @param response current HTTP response
     * @throws Exception if preparing the response failed
     */
    protected void noHandlerFound(HttpServletRequest request, HttpServletResponse response) throws Exception {
        if (!request.getPathInfo().startsWith("/svn/")) {
            if (request.getPathInfo().contains("/api")) {
                response.setStatus(HttpServletResponse.SC_NOT_FOUND);
                response.setContentType("application/json; charset=UTF-8");
                String requestUri = urlPathHelper.getRequestUri(request);
                JsonObject object = new JsonObject();

                object.addProperty(JSON_SUCCESS, false);
                object.addProperty(JSON_CAUSE,
                        "API URL " + requestUri + " [" + request.getMethod() + "] does not exist.");
                response.getWriter().write(gson.toJson(object));
                response.flushBuffer();
            } else {
                if (pageNotFoundLogger.isWarnEnabled()) {
                    String requestUri = urlPathHelper.getRequestUri(request);
                    pageNotFoundLogger.warn("No mapping found for HTTP request with URI [" + requestUri
                            + "] in DispatcherServlet with name '" + getServletName() + "'");
                }
                response.sendRedirect("/error_404");
            }
        }
    }
}