2021.3.10--3.14JavaEE2 JSP 笔记 - 《Java学习笔记---武伟》

《学习内容》：

//========学习内容=========
购物系统练习
自己扩展了内容

《知识点—笔记》
//=========================

《代码内容》：

主要思路—->通过这个购物系统的项目，自己加上扩展了2给页面，可以在最后结算的时候，在下面加了一个
button按钮，然后把当前的总金额存在request对象作用域中，请求转发到付款页面，上面是接收结算的金额
下方是自己的微信二维码。

login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %>
<html lang="en">
<head>
    <title>购物系统登录</title>
    <script type="text/javascript">
        window.onload = function () {
            var regist = document.getElementById("regist")
            regist.onclick = function () {
                window.location.href = "regist.html";
            }
        }
    </script>
</head>
        <%
            String loginResult = (String)session.getAttribute("loginResult");
            if (loginResult != null){
                out.write(loginResult+"<br>");
            }
        %>
<body>
<H2>购物系统 请您登录！</H2>
<table>
    <form action="login" method="post">
        <tr>
            <td>用户名：</td>
            <td><input type="text" name="uname" value=""></td>
        </tr>
        <tr>
            <td>密码：</td>
            <td><input type="password" name="upassword" value=""></td>
        </tr>
        <tr>
            <td><input type="submit" value="登录"></td>
            <td><input type="button" id="regist" value="注册" ></td>
        </tr>
    </form>
</table>
</body>
</html>

LoginCont**roller**

package com.atanmo.gwxt.controller;
import com.atanmo.gwxt.service.UserService;
import com.atanmo.gwxt.util.MySpring;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
public class LoginController extends HttpServlet {
    private static UserService service = MySpring.getBean("com.atanmo.gwxt.service.UserService");
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //拿到账号 密码 调用业务层 判断登录
        request.setCharacterEncoding("UTF-8");
        String uname = request.getParameter("uname");
        String loginResult = service.login(uname, request.getParameter("upassword"));
        //把登录的结果 是否成功存进一次请求中
        request.setAttribute("loginResult",loginResult);
        if ("登录成功".equals(loginResult)){
            //将用户名 存入一次会话中
            HttpSession session = request.getSession();
            session.setAttribute("uname",uname);
            //重定向发起请求
            response.sendRedirect("selectAllKind");
        }else {
            request.getRequestDispatcher("login.jsp").forward(request,response);
        }
    }
}

kind.jsp

<%@ page import="java.util.ArrayList" %>
<%@ page import="com.atanmo.gwxt.domain.Kind" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>购物系统-选择商品类别</title>
    <script type="text/javascript">
        window.onload = function () {
            var KindSelect = document.getElementById("KindSelect");
            KindSelect.onchange = function () {
                window.location.href = "selectCommodity?kid="+this.value
            }
        }
    </script>
</head>
<body>
        <h2>欢迎来到---不坑死你才怪---购物系统</h2>
            <select id="KindSelect" name="kid">
                <option>===请选择===</option>
                <%
                    ArrayList<Kind> arrayList = (ArrayList<Kind>) session.getAttribute("allKind");
                    for (Kind kind : arrayList){
                        out.write("<option value='"+kind.getKID()+"'>"+kind.getKNAME()+"</option>");
                    }
                %>
            </select>
</body>
</html>

CloseMoney.js**p**

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>付款</title>
</head>
<body>
        <table border="5" align="center" width="40%" height="40%">
            <tr fo>
                <th>请付款 总计：<%=session.getAttribute("sumMoney")%></th>
            </tr>
            <tr>
                <th>
                    <img src="static/img/closeMoneyjpg.jpg">
                </th>
            </tr>
        </table>
</body>
</html>

ShowClose.js**p**

<%@ page import="java.util.ArrayList" %>
<%@ page import="com.atanmo.gwxt.domain.Commodity" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>购物账单结算</title>
    <script>
            window.onload = function () {
                var closeButton = document.getElementById("close")
                closeButton.onclick = function () {
                        window.location.href = "closeMoney"
                }
            }
    </script>
</head>
<body>
        <form action="closeShopping" method="post">
            <table border="6" align="center" width="60%" height="30">
                <tr>
                    <th>商品名称</th>
                    <th>商品价格</th>
                </tr>
                <%
                    Float sumMoney = 0f;
                    ArrayList<Commodity> shoppingCar = (ArrayList<Commodity>)session.getAttribute("shoppingCar");
                    for (Commodity commodity : shoppingCar) {
                        out.write("<tr>");
                        out.write("<td>"+commodity.getCNAME()+"</td>");
                        out.write("<td>"+commodity.getCPRINCE()+"</td>");
                        out.write("</tr>");
                        sumMoney += commodity.getCPRINCE();
                        session.setAttribute("sumMoney",sumMoney);
                    }
                %>
                <tr>
                    <th>总计：</th>
                    <th><%=sumMoney%></th>
                </tr>
            </table>
            <table border="1" align="center">
                <tr>
                    <td><input align="center" type="button" id="close" value="结算"></td>
                </tr>
            </table>
            <input type="hidden" name="sumMoney" value="<%=sumMoney%>">
        </form>
</body>
</html>

showCommodi**tys.jsp**

<%@ page import="java.util.ArrayList" %>
<%@ page import="com.atanmo.gwxt.domain.Commodity" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>商品列表</title>
    <style>
        td{
            text-align: center;
        }
    </style>
    <script>
        window.onload = function () {
                  var buttons =  document.getElementsByClassName("countinueButton")
                  for (var i = 0;i<buttons.length;i++){
                        buttons[i].onclick = function () {
                         var hidden = document.getElementById("hidden")
                            hidden.value = this.value
                            var submitForm = document.getElementById("submitForm")
                            submitForm.submit();
                        }
                  }
        }
    </script>
</head>
<body>
    <form id= 'submitForm' action="saveSelectedCommodity" method="post">
        <table border="5" align="center" width="60%" height="60%">
            <tr>
                <th>已选商品</th>
                <th>商品名称</th>
                <th>商品单价</th>
            </tr>
                <%
                    ArrayList<Commodity> commodities = (ArrayList<Commodity>) request.getAttribute("commodities");
                    for (Commodity commodity : commodities){
                        out.write("<tr>");
                        out.write("<td><input type= 'checkbox' name='cid' value='"+commodity.getCID()+"'></td>");
                        out.write("<td>"+commodity.getCNAME()+"</td>");
                        out.write("<td>"+commodity.getCPRINCE()+"</td>");
                        out.write("</tr>");
                    }
                %>
            <tr>
                <td colspan="3">
                    <input class= "countinueButton" type="button" value="继续购物">
                    &nbsp;&nbsp;||&nbsp;&nbsp;
                    <input class="countinueButton" type="button" value="结算清单">
                </td>
            </tr>
        </table>
        <input id='hidden' type="hidden" name="buttonValue" value="">
    </form>
</body>
</html>

CloseMoneyCon**troller**

package com.atanmo.gwxt.controller;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CloseMoneyController extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        String sumMoney = request.getParameter("sumMoney");
        request.getRequestDispatcher("CloseMoney.jsp").forward(request,response);
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doPost(request,response);
    }
}

SaveSelectedComm**oditysController**

package com.atanmo.gwxt.controller;
import com.atanmo.gwxt.domain.Commodity;
import com.atanmo.gwxt.service.CommodityService;
import com.atanmo.gwxt.util.MySpring;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.ArrayList;
public class saveSelectedCommodityController extends HttpServlet {
    private static CommodityService service = MySpring.getBean("com.atanmo.gwxt.service.CommodityService");
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        //获取前端的参数是 继续购物 还是 结算
        String buttonValue = request.getParameter("buttonValue");
        //获取前端的已选商品的参数
        String[] cids = request.getParameterValues("cid");
        HttpSession session = request.getSession();
        //到session中去拿这个集合
        ArrayList<Commodity> shoppingCar = (ArrayList<Commodity>)session.getAttribute("shoppingCar");
        if (shoppingCar == null){
            //调用service方法来通过
            shoppingCar = service.getSelectedCommodityList(cids);
            session.setAttribute("shoppingCar",shoppingCar);
        }
        //到此为止，已经把用户选择的商品全部存入了集合中  那么我们来判断他点的是继续购物还是 结算
        if ("继续购物".equals(buttonValue)){
            request.getRequestDispatcher("kind.jsp").forward(request,response);
        }else {
            request.getRequestDispatcher("ShowClose.jsp").forward(request,response);
        }
        System.out.println(buttonValue);
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

SelectAllkindCon**troller**

package com.atanmo.gwxt.controller;

import com.atanmo.gwxt.domain.Kind;
import com.atanmo.gwxt.service.KindService;
import com.atanmo.gwxt.util.MySpring;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.ArrayList;

public class SelectAllKindController extends HttpServlet {

    private static KindService kindService = MySpring.getBean("com.atanmo.gwxt.service.KindService");


    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //调用业务层方法 查询全部的类别
            ArrayList<Kind> allKind = kindService.selectAllKind();
        HttpSession session = request.getSession();
        session.setAttribute("allKind",allKind);
        request.getRequestDispatcher("kind.jsp").forward(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doPost(request,response);
    }
}

SelectCommodityCont**roller**

package com.atanmo.gwxt.controller;

import com.atanmo.gwxt.dao.CommodityDao;
import com.atanmo.gwxt.domain.Commodity;
import com.atanmo.gwxt.service.CommodityService;
import com.atanmo.gwxt.util.MySpring;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;

public class SelectCommodityController extends HttpServlet {

    private static CommodityService service = MySpring.getBean("com.atanmo.gwxt.service.CommodityService");

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            request.setCharacterEncoding("UTF-8");
            String kid = request.getParameter("kid");
            //调用业务层去给我找这个kid对应的全部商品
        ArrayList<Commodity> commodities = service.selectAllCommmodity(Integer.parseInt(kid));
        request.setAttribute("commodities",commodities);
        request.getRequestDispatcher("showCommoditys.jsp").forward(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doPost(request,response);
    }
}

CommodityD**ao**

package com.atanmo.gwxt.dao;

import com.atanmo.gwxt.domain.Commodity;
import com.atanmo.gwxt.domain.Kind;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;

@SuppressWarnings("all")
public class CommodityDao {

    private String driver = "com.mysql.cj.jdbc.Driver";
    private String url = "jdbc:mysql://localhost:3306/shopping?serverTimezone=CST&characterEncoding=UTF-8";
    private String username = "root";
    private String password = "at123123";

    public ArrayList<Commodity> selectAllCommodity(Integer kid) {
        ArrayList<Commodity> kidOrmCommodity = new ArrayList<>();
        Kind kind = null;
        try {
            Class.forName(driver);
            Connection conn = DriverManager.getConnection(url, username, password);
            String sql = "SELECT CID,CNAME,CPRINCE,KID FROM T_COMMODITY WHERE KID = ?";
            PreparedStatement pstat = conn.prepareStatement(sql);
            pstat.setInt(1,kid);
            ResultSet rst = pstat.executeQuery();
            while (rst.next()){
                Commodity commodity = new Commodity(
                        rst.getInt("CID"),
                        rst.getString("CNAME"),
                        rst.getFloat("CPRINCE"),
                        kind = new Kind()
                );
                kind.setKID(kid);
                kidOrmCommodity.add(commodity);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        return kidOrmCommodity;
    }

    public Commodity selectSelectedCommoditys(Integer cid) {
        Commodity commodity = null;
        Kind kind = new Kind();
        try {
            Class.forName(driver);
            Connection conn = DriverManager.getConnection(url, username, password);
            String sql = "SELECT CID,CNAME,CPRINCE,KID FROM T_COMMODITY WHERE CID = ?";
            PreparedStatement pstat = conn.prepareStatement(sql);
            pstat.setInt(1,cid);
            ResultSet rst = pstat.executeQuery();
            if (rst.next()){
                kind.setKID(rst.getInt("KID"));
                commodity = new Commodity(
                        rst.getInt("CID"),rst.getString("CNAME"),
                        rst.getFloat("CPRINCE"),kind);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return commodity;
    }
}

KindD**ao**

package com.atanmo.gwxt.dao;

import com.atanmo.gwxt.domain.Kind;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;

public class KindDao {

    private String driver = "com.mysql.cj.jdbc.Driver";
    private String url = "jdbc:mysql://localhost:3306/shopping?serverTimezone=CST&characterEncoding=UTF-8";
    private String username = "root";
    private String password = "at123123";

    public ArrayList<Kind> selectAllKind() {
        ArrayList<Kind> kindMap = new ArrayList<>();
        try {
            Class.forName(driver);
            Connection conn = DriverManager.getConnection(url,username,password);
            String sql = "SELECT KID,KNAME FROM T_KIND";
            PreparedStatement pstat = conn.prepareStatement(sql);
            ResultSet rst = pstat.executeQuery();
            while (rst.next()){
                Kind kind = new Kind(rst.getInt("KID"), rst.getString("KNAME"));
                kindMap.add(kind);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return kindMap;
    }
}

UserDa**o**

package com.atanmo.gwxt.dao;

import com.atanmo.gwxt.domain.User;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class  UserDao {

    private String driver = "com.mysql.cj.jdbc.Driver";
    private String url = "jdbc:mysql://localhost:3306/shopping?serverTimezone=CST&characterEncoding=UTF-8";
    private String username = "root";
    private String password = "at123123";


    public User checkLoginResult(String uname){
            User user = null;
        try {
            Class.forName(driver);
            Connection conn = DriverManager.getConnection(url, username, password);
            String sql = "SELECT * FROM T_USER WHERE UNAME = ?";
            PreparedStatement pstat = conn.prepareStatement(sql);
            if (uname != null) {
                pstat.setString(1, uname);
                ResultSet rst = pstat.executeQuery();
                if (rst.next()) {
                    user = new User();
                    user.setUID(rst.getInt("UID"));
                    user.setUNAME(rst.getString("UNAME"));
                    user.setUPASSWORD(rst.getString("UPASSWORD"));
                    user.setYULIU1(rst.getString("YULIU1"));
                    user.setYULIU2(rst.getString("YULIU2"));
                }
            }else {
                return user;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return user;
    }

}

Commo**dity**

package com.atanmo.gwxt.domain;

public class Commodity {

    private Integer CID;
    private String CNAME;
    private Float CPRINCE;
    private Kind kind;


    public Commodity() {}
    public Commodity(Integer CID, String CNAME, Float CPRINCE, Kind kind) {
        this.CID = CID;
        this.CNAME = CNAME;
        this.CPRINCE = CPRINCE;
        this.kind = kind;
    }

    public Integer getCID() {
        return CID;
    }

    public void setCID(Integer CID) {
        this.CID = CID;
    }

    public String getCNAME() {
        return CNAME;
    }

    public void setCNAME(String CNAME) {
        this.CNAME = CNAME;
    }

    public Float getCPRINCE() {
        return CPRINCE;
    }

    public void setCPRINCE(Float CPRINCE) {
        this.CPRINCE = CPRINCE;
    }

    public Kind getKind() {
        return kind;
    }

    public void setKind(Kind kind) {
        this.kind = kind;
    }

    @Override
    public String toString() {
        return "Commodity{" +
                "CID=" + CID +
                ", CNAME='" + CNAME + '\'' +
                ", CPRINCE=" + CPRINCE +
                ", kind=" + kind +
                '}';
    }
}

Kind

package com.atanmo.gwxt.domain;

public class Kind {
    private Integer KID;
    private String KNAME;

    public Kind() {}
    public Kind(Integer KID, String KNAME) {
        this.KID = KID;
        this.KNAME = KNAME;
    }

    public Integer getKID() {
        return KID;
    }

    public void setKID(Integer KID) {
        this.KID = KID;
    }

    public String getKNAME() {
        return KNAME;
    }

    public void setKNAME(String KNAME) {
        this.KNAME = KNAME;
    }

    @Override
    public String toString() {
        return "Kind{" +
                "KID=" + KID +
                ", KNAME='" + KNAME + '\'' +
                '}';
    }
}

Us**er**

package com.atanmo.gwxt.domain;

import java.util.PrimitiveIterator;

public class User {

    private Integer UID;
    private String UNAME;
    private String UPASSWORD;
    private String YULIU1;
    private String YULIU2;

    public User() {}
    public User(Integer UID, String UNAME, String UPASSWORD, String YULIU1, String YULIU2) {
        this.UID = UID;
        this.UNAME = UNAME;
        this.UPASSWORD = UPASSWORD;
        this.YULIU1 = YULIU1;
        this.YULIU2 = YULIU2;
    }

    public Integer getUID() {
        return UID;
    }

    public void setUID(Integer UID) {
        this.UID = UID;
    }

    public String getUNAME() {
        return UNAME;
    }

    public void setUNAME(String UNAME) {
        this.UNAME = UNAME;
    }

    public String getUPASSWORD() {
        return UPASSWORD;
    }

    public void setUPASSWORD(String UPASSWORD) {
        this.UPASSWORD = UPASSWORD;
    }

    public String getYULIU1() {
        return YULIU1;
    }

    public void setYULIU1(String YULIU1) {
        this.YULIU1 = YULIU1;
    }

    public String getYULIU2() {
        return YULIU2;
    }

    public void setYULIU2(String YULIU2) {
        this.YULIU2 = YULIU2;
    }

    @Override
    public String toString() {
        return "User{" +
                "UID=" + UID +
                ", UNAME='" + UNAME + '\'' +
                ", UPASSWORD='" + UPASSWORD + '\'' +
                ", YULIU1='" + YULIU1 + '\'' +
                ", YULIU2='" + YULIU2 + '\'' +
                '}';
    }
}

Commodity**Service**

package com.atanmo.gwxt.service;

import com.atanmo.gwxt.dao.CommodityDao;
import com.atanmo.gwxt.domain.Commodity;
import com.atanmo.gwxt.util.MySpring;

import javax.swing.*;
import java.util.ArrayList;

public class CommodityService {

    private static CommodityDao dao = MySpring.getBean("com.atanmo.gwxt.dao.CommodityDao");

    public ArrayList<Commodity> selectAllCommmodity(Integer kid){
        //调用dao去读写数据库
        return dao.selectAllCommodity(kid);
    }

    public ArrayList<Commodity> getSelectedCommodityList(String[] cids) {
        ArrayList<Commodity> commodities = new ArrayList<>();
        //将前端获取的cid全部获取 然后通过cid去传给service方法来查出一组对象，放到集合中
        for (String cid : cids){
            //调用dao来查出全部的已选商品
            commodities.add(dao.selectSelectedCommoditys(Integer.parseInt(cid)));
        }
        return commodities;
    }
}

KindServi**ce**

package com.atanmo.gwxt.service;

import com.atanmo.gwxt.dao.KindDao;
import com.atanmo.gwxt.domain.Kind;
import com.atanmo.gwxt.util.MySpring;

import java.util.ArrayList;

public class KindService {

    private static KindDao kindDao = MySpring.getBean("com.atanmo.gwxt.dao.KindDao");

    public ArrayList<Kind> selectAllKind(){
        //调用Dao查询全部的Kind类别
       return kindDao.selectAllKind();
    }

}

UserSe**rvice**

package com.atanmo.gwxt.service;

import com.atanmo.gwxt.dao.UserDao;
import com.atanmo.gwxt.domain.User;
import com.atanmo.gwxt.util.MySpring;

public class UserService {

    private static UserDao userDao = MySpring.getBean("com.atanmo.gwxt.dao.UserDao");

    public String login(String uname,String upasssword){
        //调用dao查询一条记录
        User user = userDao.checkLoginResult(uname);
        System.out.println(user);
        if (user != null && user.getUPASSWORD().equals(upasssword)){
            return "登录成功";
        }
        return "用户名或密码错误";
    }

}

MySp**ring**

package com.atanmo.gwxt.util;

import java.util.HashMap;

public class MySpring {

    private static HashMap<String,Object> beanMap = new HashMap<>();

    public static <T> T getBean(String className){
            T obj = (T)beanMap.get(className);
            if (obj == null){
                try {
                    Class<?> clazz = Class.forName(className);
                    obj = (T)clazz.newInstance();
                    beanMap.put(className,obj);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
         return obj;
    }


}

学习总结：
学懂的：
我通过这次的购物系统的练习，觉得这不仅仅是锻炼了自己的面向独享思想，作用域对象的使用，
知识的巩固，更是提升编码能力和锻炼独立思维的练习
有问题的地方：
在saveSelectedCommodity中无法把选中的全部商品结算，我觉得是session对象的存储问题
正在排查.**