项目实战：优化Servlet，把所有围绕Fruit操作的Servlet封装成一个Servlet

1、FruitServlet

• 这些Servlet都是围绕着Fruit进行的
• 把所有对水果增删改查的Servlet放到一个Servlet里面，让tomcat实例化一个Servlet对象

package com.csdn.fruit.servlet;
import com.csdn.fruit.dto.PageInfo;
import com.csdn.fruit.dto.PageQueryParam;
import com.csdn.fruit.dto.Result;
import com.csdn.fruit.pojo.Fruit;
import com.csdn.fruit.service.FruitService;
import com.csdn.fruit.service.impl.FruitServiceImpl;
import com.csdn.fruit.util.RequestUtil;
import com.csdn.fruit.util.ResponseUtil;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet("/fruit/*")
public class FruitServlet extends HttpServlet {private FruitService fruitService = new FruitServiceImpl();@Overrideprotected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//     /fruit/indexString uri = req.getRequestURI();uri = uri.substring(1);String[] split = uri.split("/");String methodName = split[1];switch (methodName) {case "index" ->index(req,resp);case "add"-> add(req, resp);case "del"->del(req,resp);case "edit"->edit(req,resp);case "getFname"-> getFname(req, resp);case "update"  -> update(req, resp);}}protected void index(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Integer pageNo = 1;String pageNoStr = req.getParameter("pageNo");if (pageNoStr != null && !"".equals(pageNoStr)) {pageNo = Integer.parseInt(pageNoStr);}String keyword = "";String keywordStr = req.getParameter("keyword");if (keywordStr != null) {keyword = keywordStr;}PageQueryParam pageQueryParam = new PageQueryParam(pageNo, 5, keyword);PageInfo<Fruit> pageInfo = fruitService.getFruitPageInfo(pageQueryParam);Result result = Result.OK(pageInfo);ResponseUtil.print(resp, result);}protected void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Fruit fruit = (Fruit) RequestUtil.readObject(req, Fruit.class);fruitService.addFruit(fruit);ResponseUtil.print(resp, Result.OK());}protected void del(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Integer fid = Integer.parseInt(req.getParameter("fid"));fruitService.delFruit(fid);ResponseUtil.print(resp, Result.OK());}protected void edit(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Integer fid = Integer.parseInt(req.getParameter("fid"));Fruit fruit = fruitService.getFruitById(fid);ResponseUtil.print(resp, Result.OK(fruit));}public void getFname(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String fname = req.getParameter("fname");Fruit fruit = fruitService.getFruitByFname(fname);ResponseUtil.print(resp, fruit == null ? Result.OK() : Result.Fail());}protected void update(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Fruit fruit = (Fruit) RequestUtil.readObject(req, Fruit.class);fruitService.updateFruit(fruit);ResponseUtil.print(resp, Result.OK());}
}

 2、修改js中axios中的url路径

 2.2、公共的common.js

function $(key){if(key){if(key.startsWith("#")){key = key.substring(1)return document.getElementById(key)}else{let nodeList = document.getElementsByName(key)return Array.from(nodeList)}}
}

2.2.1、index.js

let pageNo = 1;
let pageCount = 0;
let keyword=""//当页面加载完成，执行匿名函数
window.onload=function(){loadData();
}
function search() {keyword=$("#keyword").valueloadData(pageNo)
}function page(str) {if (str) {if (str == "first") {pageNo = 1;}else if (str == "pre") {pageNo = pageNo - 1;}else if (str == "next") {pageNo = pageNo + 1;}else if (str == "last") {pageNo = pageCount;}if (pageNo > pageCount) {pageNo=pageCount}if (pageNo <= 0) {pageNo=1}}loadData(pageNo)
}
loadData=function(pageNo=1){//pageNo这个参数有默认值，如果没有传值，则使用默认值 1axios({method: 'get',url: '/fruit/index',params: {pageNo: pageNo,keyword:keyword}}).then(response => {debuggerlet fruitList = response.data.data.listpageNo = response.data.data.pageNopageCount = response.data.data.pageCount// 此处使用的是axios，那么响应回来的数据自动就是json，// 不需要再进行parse(如果是原始的ajax操作，那么一定需要parse)// let fruitArr = JSON.parse(fruitList)let fruitArr = fruitList;let fruitTbl = $("#fruit_tbl")//向表格中添加行之前，先删除原来的行let rows=fruitTbl.rowsfor (let i = rows.length - 1; i >= 1; i--) {fruitTbl.deleteRow(i);}for (let i = 0; i < fruitArr.length; i++) {let tr = fruitTbl.insertRow();let fnameTD = tr.insertCell();let priceTD = tr.insertCell();let fcountTD = tr.insertCell();let operTD = tr.insertCell();let fruit = fruitArr[i];//fnameTD.innerText = fruit.fnamefnameTD.innerHTML = '<a href="edit.html?fid=' + fruit.fid + '">' + fruit.fname + '</a>';priceTD.innerText = fruit.price;fcountTD.innerText = fruit.fcount;operTD.innerHTML = "<img class=\"delImg\" src=\"imgs/del.png\" onclick=\"delFruit(" + fruit.fid + ")\"/>";}});
}delFruit = function (fid) {if (window.confirm('是否确认删除？')) {axios({method: 'get',url: '/fruit/del',params:{fid: fid,}}).then(response=>{if (response.data.flag) {window.location.reload();}});}
};

2.2.2、edit.js

let queryString = window.location.search.substring(1)
if(queryString){var fid = queryString.split("=")[1]window.onload=function(){loadFruit(fid)}loadFruit = function(fid){axios({method:'get',url:'/fruit/edit',params:{fid:fid}}).then(response=>{debuggerlet fruit = response.data.data$("#fid").value=fruit.fid$("#fname").value=fruit.fname$("#price").value=fruit.price$("#fcount").value=fruit.fcount$("#remark").value=fruit.remark})}update=function(){let fid = $("#fid").valuelet fname = $("#fname").valuelet price = $("#price").valuelet fcount = $("#fcount").valuelet remark = $("#remark").valueaxios({method:'post',url:"/fruit/update",data:{fid:fid,fname:fname,price:price,fcount:fcount,remark:remark}}).then(response=>{if(response.data.flag){window.location.href="index.html"}})}
}

2.2.3、add.js

function add(){let fname = $("#fname").valuelet price = $("#price").valuelet fcount = $("#fcount").valuelet remark = $("#remark").value//let fruit = {"fname":fname,"price":price,"fcount":fcount,"remark":remark}let fruit = {}fruit.fname=fnamefruit.price = pricefruit.fcount=fcountfruit.remark=remarkaxios({method:'post',url:'/fruit/add',data:fruit}).then(response=>{if(response.data.flag){window.location.href='index.html'}})
}function checkFname(fname){axios({method:'get',url:"/fruit/getFname",params:{fname:fname}}).then(response=>{let fnameSpan= $("#fnameSpan");if(response.data.flag){fnameSpan.innerText = '名称可添加'fnameSpan.style.color='green'}else{fnameSpan.innerText = '名称已存在'fnameSpan.style.color='red'}})
}