接上一篇：

5 创建FavoriteServlet的父类BaseServlet

package cn.itcast.travel.web.servlet1.base;

import com.fasterxml.jackson.databind.ObjectMapper;

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 java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;


public class BaseServlet extends HttpServlet {

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        StringBuffer url = req.getRequestURL();
        System.out.println(url);
        String methodName = url.substring(url.lastIndexOf("/") + 1);
        System.out.println("methodName:"+methodName);

        try {
            Method method = this.getClass().getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        }catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }

    public String writeValueAstring(HttpServletResponse response,Object obj) throws IOException{
        ObjectMapper mapper=new ObjectMapper();
            return mapper.writeValueAsString(obj);


    }
    public void writeValue(HttpServletResponse response,Object obj) throws IOException{
        ObjectMapper mapper=new ObjectMapper();
        response.setContentType("application/json;charset=utf-8");
        mapper.writeValue(response.getOutputStream(),obj);
    }

}

6 创建FavoriteServlet调用service层，向前端返回数据

package cn.itcast.travel.web.servlet1;

import cn.itcast.travel.domain.PageBean;
import cn.itcast.travel.domain.Route;
import cn.itcast.travel.domain.User;
import cn.itcast.travel.service.FavoriteService;
import cn.itcast.travel.service.PageBeanService;
import cn.itcast.travel.service.impl.FavoriteServiceImp;
import cn.itcast.travel.service.impl.PageBeanServiceImp;
import cn.itcast.travel.web.servlet1.base.BaseServlet;

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 java.io.IOException;
import java.util.ArrayList;
import java.util.List;

@WebServlet("/favorite/*")
public class FavoriteServlet extends BaseServlet {
    FavoriteService favoriteService=new FavoriteServiceImp();

    public void favoriteOrder(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String cid="";
        String currentPage = request.getParameter("currentPage");
        String cname = request.getParameter("cname");
        String highPrice = request.getParameter("highPrice");
        String lowPrice = request.getParameter("lowPrice");
        String pageSize="8";
        PageBean pageBean=favoriteService.findRouteOrderPageBean(cid,currentPage,cname,highPrice,lowPrice,pageSize);
        writeValue(response,pageBean);
    }
    }