Java Servlet: 建立具有 Router 的功能

為了限制存取檔案，這個方法是將網址參數蓋過，並由此功能代理去尋找 "可存取" 的檔案，再回送給使用者。

建立總覆蓋路由

一旦我這麼做了，整個參數後面的路徑都會經過這個 Servlet 處理。

package com.permission;

import com.apostlescookies.ApostlesCookies;
import com.util.UB_AES;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URI;
import java.net.URLDecoder;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import javax.activation.MimetypesFileTypeMap;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.FilenameUtils;
import org.json.JSONObject;

/**
 *
 * @author Mac
 */
@WebServlet(urlPatterns = {"/administrator/*"})  //設定這個路徑
public class AdministratorRouting extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //response.setContentType("text/html;charset=UTF-8");
        try{
            /*這裡可以寫控管權限，像是撈出 Session, Cookie...etc*/
            
            String ext = FilenameUtils.getExtension(request.getPathInfo());
            if(ext.equals("css") || ext.equals("png") || ext.equals("js")){
                MimetypesFileTypeMap mimeMap = new MimetypesFileTypeMap();
                mimeMap.addMimeTypes("text/css css");
                mimeMap.addMimeTypes("text/javascript js");
                mimeMap.addMimeTypes("image/png png");
                mimeMap.addMimeTypes("text/html html");
                response.setContentType(mimeMap.getContentType(request.getPathInfo()));
            }
            //撈出本機目錄底下的資料夾檔案
            request.getRequestDispatcher("/WEB-INF/Administrator/"+request.getPathInfo()).include(request, response);
        }catch(Exception e){     //找不到就回傳 404
            System.out.println(e);
            response.setContentType("text/html;charset=UTF-8");
            response.getWriter().print("<h1>404 NOT FOUND</h1>");
            response.getWriter().close();
        }
    }
}