com.centurylink.mdw.hub.servlet.RootServlet Maven / Gradle / Ivy

Go to download
/*
 * Copyright (C) 2017 CenturyLink, Inc.
 *
 * 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 com.centurylink.mdw.hub.servlet;

import java.io.File;
import java.io.IOException;
import java.util.Scanner;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.centurylink.mdw.common.MdwException;
import com.centurylink.mdw.hub.context.ContextPaths;
import com.centurylink.mdw.hub.context.WebAppContext;
import com.centurylink.mdw.util.file.FileHelper;

@WebServlet(urlPatterns={"/index.html"}, loadOnStartup=1)
public class RootServlet extends HttpServlet {

    private static ContextPaths contextPaths = new ContextPaths();

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String path = request.getServletPath();
        if (path.equals("/") || path.equals("/index.html")) {
            response.setCharacterEncoding("UTF-8"); // why oh why does servlet spec default to ISO-8859-1?
            if (new File(WebAppContext.getMdw().getOverrideRoot() + "/index.html").isFile()) {
                request.getRequestDispatcher("/customContent/index.html").forward(request, response);
            }
            else {
                // standard index.html -- read and process (never cached since asset injection may change)
                response.setContentType("text/html");
                String realPath = request.getSession().getServletContext().getRealPath("/index.html");

                try {
                    String contents;
                    if (realPath == null)  {
                        // read from classpath
                        contents = new String(FileHelper.readFromResourceStream(getClass().getClassLoader().getResourceAsStream("index.html")));
                    }
                    else {
                        if (!new File(realPath).isFile() && getClass().getClassLoader().getResource("/org/springframework/web/servlet/ResourceServlet.class") != null) {
                            // spring-boot client app
                            try (Scanner scanner = new Scanner(getClass().getClassLoader().getResourceAsStream("mdw/index.html"), "utf-8")) {
                                contents = scanner.useDelimiter("\\Z").next();
                            }
                        }
                        else {
                            contents = FileHelper.readFromFile(realPath);
                        }
                    }

                    response.getWriter().println(contextPaths.processIndex(contents));
                }
                catch (IOException ex) {
                    // TODO: logging
                    ex.printStackTrace();
                    throw ex;
                }
                catch (MdwException ex) {
                    // TODO: logging
                    ex.printStackTrace();
                    throw new IOException(ex.getMessage(), ex);
                }
            }
        }
    }
}