项目实战系列三: 家居购项目 第二部分

本文主要是介绍项目实战系列三: 家居购项目 第二部分，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

🐇servlet合并

需求
1.如果处理一个请求, 就对应一个Servlet, 会造成Servlet文件太多, 不利于管理.
2.在项目开发中, 同一个业务(模块), 一般对应一个Servlet即可, 比如LoginServlet, RegisterServlet, 都是在处理和会员相关的业务, 应当合并.

🍎方案一: 隐藏域

1.给login和register表单增加hidden元素, 区分登录和注册.
2但信息提交到MemberServlet后, 获取action参数值
3.分发请求.

代码实现
1.修改web/views/member/login.jsp, 增加隐藏域, 修改请求url为memberServlet

2.新建src/com/zzw/furns/web/MemberServlet.java, 合并到MemberServlet

public class MemberServlet extends HttpServlet {private MemberService memberService = new MemberServiceImpl();@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String action = request.getParameter("action");if ("login".equals(action)) {login(request, response);} else if ("register".equals(action)) {register(request, response);} else {response.setContentType("text/html;charset=UTF-8");response.getWriter().write("<h1>404</h1>");}}protected void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String username = request.getParameter("username");String password = request.getParameter("password");Member member = new Member(null, username, password, null);if (member != null) {System.out.println("登录成功");request.getRequestDispatcher("/views/member/login_ok.jsp").forward(request, response);} else {System.out.println("登录失败");request.setAttribute("msg", "用户名或密码错误，请重新登录");request.setAttribute("username", username);request.getRequestDispatcher(request.getHeader("Referer")).forward(request, response);}}protected void register(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String username = request.getParameter("username");String password = request.getParameter("password");String email = request.getParameter("email");Member member = new Member(null, username, password, email);if (!memberService.isExistsByUsername(username)) {//用户名可用if (memberService.registerMember(member)) {//注册成功System.out.println("注册成功，请登录");request.getRequestDispatcher("/views/member/register_ok.jsp").forward(request, response);} else {//注册失败System.out.println("注册失败，请重新注册");request.getRequestDispatcher("/views/member/register_fail.jsp").forward(request, response);}} else {request.setCharacterEncoding("UTF-8");request.setAttribute("msg", "用户名已存在，请重新注册");request.setAttribute("username", username);request.setAttribute("active", "register_tab");request.getRequestDispatcher("/views/member/login.jsp").forward(request, response);}}
}

3.测试…

🍎方案二: 反射+模板设计模式+动态代理

1.新建BasicServlet类, 继承HttpServlet

public class BasicServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String action = req.getParameter("action");try {//1.得到子类对应的class对象Class<? extends BasicServlet> aClass = this.getClass();//2.创建对象Object o = aClass.newInstance();//3.得到action方法对象Method declaredMethod = this.getClass().getDeclaredMethod(action, HttpServletRequest.class, HttpServletResponse.class);declaredMethod.invoke(o, req, resp);} catch (Exception e) {throw new RuntimeException(e);}}
}

2.子类中没有doGet, doPost方法, 会调用父类的doGet, doPost.

🌳显示家居

需求分析
1.给后台管理提供独立登陆页面 [manage_login.jsp(已提供)
2.管理员(admin表)登陆成功后, 显示管理菜单页面
3.管理员点击家居管理, 显示所有家居信息

程序框架图

1.页面准备

2.新建admin表 👉 参考member表

-- 创建会员表
CREATE TABLE admin (id INT PRIMARY KEY AUTO_INCREMENT,username VARCHAR(32) NOT NULL DEFAULT '' UNIQUE,`password` VARCHAR(32) NOT NULL,email VARCHAR(64)
)CHARSET utf8 ENGINE INNODB;-- 插入数据
INSERT INTO admin VALUES(NULL, 'admin', MD5('admin'), '978964140@qq.com');
INSERT INTO admin VALUES(NULL, 'zhaozhiwei', MD5('zhaozhiwei'), '978964140@qq.com');
INSERT INTO admin(id, username, `password`, email) VALUES(NULL, 'tom', MD5('tom'), 'tom@sohu.com');-- 查询
SELECT * FROM admin;
SELECT id, username, `password`, email FROM admin WHERE username = 'admine'
SELECT id, username, `password`, email FROM admin WHERE username = 'admin123' AND `password` = MD5('123456');UPDATE admin SET `password`=MD5('admin') WHERE username='admin';

3.新建furn表

-- 创建家居网购需要的数据库和表
-- 删除数据库
DROP DATABASE IF EXISTS home_furnishing;-- 删除表
DROP TABLE furn;-- 创建数据库
CREATE DATABASE home_furnishing;-- 切换
USE home_furnishing;-- id int(11) 11表示的是宽度
-- id int(2)  2表示的也是宽度
-- 66360 -> int(11)  00000066360
-- 66360 -> int(2)   66360
-- unsigned 无符号类型,表示的范围大一些-- 创建家居表
CREATE TABLE furn (id INT(10) UNSIGNED PRIMARY KEY AUTO_INCREMENT, -- id编号`name` VARCHAR(32) NOT NULL,-- 家居名business VARCHAR(32) NOT NULL,-- 商家price DECIMAL(10, 2) NOT NULL,-- 价格saleNum INT UNSIGNED NOT NULL,-- 销量inventory INT UNSIGNED NOT NULL,-- 库存image_path VARCHAR(256) NOT NULL -- 图片
)CHARSET utf8 ENGINE INNODB;-- 插入数据
insert into `furn` (`id`, `name`, `business`, `price`, `saleNum`, `inventory`, `image_path`) values('1','小台灯','南极人','35.50','3002','6998','assets/images/product-image/default.jpg');
insert into `furn` (`id`, `name`, `business`, `price`, `saleNum`, `inventory`, `image_path`) values('2','黑丝袜','南极人','25.50','4002','5998','assets/images/product-image/default.jpg');
insert into `furn` (`id`, `name`, `business`, `price`, `saleNum`, `inventory`, `image_path`) values('3','胸罩','南极人','45.50','5002','4998','assets/images/product-image/default.jpg');-- 查询数据
SELECT id, `name`, business, price, saleNum, inventory, image_path FROM furn WHERE `name` = '小台灯' LIMIT 1, 3;
SELECT id, `name`, business, price, saleNum, inventory, image_path FROM furn
SELECT COUNT(*) FROM furn WHERE `name` LIKE '%台%';-- 删除数据
DELETE FROM furn WHERE id = 32;-- 修改数据
UPDATE furn SET image_path = 'assets/images/product-image/default.jpg';
UPDATE furn SET `name`='手机', business='小米', price=3000, saleNum=9000, inventory=9000, image_path='zzw' WHERE id=37
UPDATE furn SET `name`='笔记本', business='戴尔', price=6000.00, saleNum=6500, inventory=5500 WHERE id=75;

4.新建Admin实体类 src/com/zzw/furns/entity/Admin.java

public class Admin {private Integer id;private String username;private String password;private String email;public Admin() {}
}

5.新建Furn实体类(无参构造器与set方法底层反射用, get方法前端EL表达式用) src/com/zzw/furns/entity/Furn.java

public class Furn {private String name;private String business;private BigDecimal price;//Decimal对应BigDecimalprivate Integer saleNum;private Integer inventory;private String imagePath;public Furn() {}
}

6.新建src/com/zzw/furns/dao/AdminDao.java

public interface AdminDAO {//根据用户名和密码查询数据库中有无对应的Admin对象public Admin queryAdminByUsernameAndPassword(String username, String password);
}

7.新建src/com/zzw/furns/dao/impl/AdminDaoImpl.java

public class AdminDAOImpl extends BasicDAO<Admin> implements AdminDAO {/*** 根据用户名和密码查询对应的Admin对象* @param username 用户名* @param password 密码* @return 对应的Admin对象, 如果没有 则返回null*/@Overridepublic Admin queryAdminByUsernameAndPassword(String username, String password) {String sql = "SELECT id, username, `password`, email FROM admin WHERE username = ? AND `password` = MD5(?)";Admin admin = querySingle(sql, Admin.class, username, password);return admin;}
}

8.测试, 新建src/com/zzw/furns/test/AdminDAOTest.java

public class AdminDAOTest {private AdminDAO adminDAO = new AdminDAOImpl();@Testpublic void queryAdminByUsernameAndPassword() {String username = "zhaozhiwei";String password = "123123";Admin admin = adminDAO.queryAdminByUsernameAndPassword(username, password);System.out.println(admin);}
}

9.新建src/com/zzw/furns/service/AdminService.java

public interface AdminService {/*** 根据传入的admin信息, 返回对应在DB中的admin对象* @param admin 是根据用户登录构建一个admin* @return 返回的是对应的DB中的admin对象, 如果不存在返回null*/public Admin login(Admin admin);
}

10.新建src/com/zzw/furns/service/AdminServiceImpl.java

public class AdminServiceImpl implements AdminService {private AdminDAO adminDAO = new AdminDAOImpl();/*** 判断用户名和密码是否存在* @param username 用户名* @param password 密码* @return*/@Overridepublic Admin login(Admin admin) {//返回一个对象return adminDAO.queryAdminByUsernameAndPassword(admin.getUsername(), admin.getPassword());}
}

11.测试, 新建src/com/zzw/furns/test/AdminServiceTest.java

public class AdminServiceTest {private AdminService adminService = new AdminServiceImpl();@Testpublic void login() {Admin admin = new Admin(null, "zhaozhiwei", "123123", null);Admin login = adminService.login(admin);System.out.println("login = " + login);}
}

12.新建src/com/zzw/furns/dao/FurnDao.java

public interface FurnDAO {//返回所有Furn对象public List<Furn> list();
}

13.新建src/com/zzw/furns/dao/impl/FurnDaoImpl.java
给字段起别名, 对应实体类的某一个属性

public class FurnDAOImpl extends BasicDAO<Furn> implements FurnDAO {@Overridepublic List<Furn> listAll() {String sql = "SELECT id, `name`, business, price, saleNum, inventory, image_path as imagePath FROM furn";List<Furn> furns = queryMany(sql, Furn.class);return furns;}
}

14.测试, 新建src/com/zzw/furns/test/FurnDaoTest.java

public class FurnDAOTest {private FurnDAO furnDAO = new FurnDAOImpl();@Testpublic void listAll() {List<Furn> furns = furnDAO.listAll();for (Furn furn : furns) {System.out.println(furn);}}
}

15.新建src/com/zzw/furns/service/FurnService.java

public interface FurnService {//显示家居public List<Furn> queryFurn();
}

16.新建src/com/zzw/furns/service/AdminServiceImpl.java

public class FurnServiceImpl implements FurnService {private FurnDAO furnDAO = new FurnDAOImpl();@Overridepublic List<Furn> queryFurn() {List<Furn> furns = furnDAO.listAll();return furns;}
}

17.测试, 新建src/com/zzw/furns/test/AdminServiceTest.java

public class FurnServiceTest {private FurnService furnService = new FurnServiceImpl();@Testpublic void queryFurn() {List<Furn> furns =  furnService.queryFurn();for (int i = 0; i < furns.size(); i++) {System.out.println(furns.get(i));}}
}

18.接通web层, 创建src/com/zzw/furns/web/AdminServlet.java, 管理员登录Servlet

public class AdminServlet extends BasicServlet {private AdminService adminService = new AdminServiceImpl();protected void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//如果在登陆界面用户没有输入内容, 后台接收到的是""String username = request.getParameter("username");String password = request.getParameter("password");Admin admin = new Admin(null, username, password, null);admin = adminService.login(admin);if (admin != null) {//用户存在DBSystem.out.println("管理员登陆成功...");request.getRequestDispatcher("/views/manage/manage_menu.jsp").forward(request, response);} else {//用户不存在System.out.println("该管理员用户不存在, 登陆失败");request.setAttribute("username", username);request.setAttribute("errorMsg", "用户名或密码不正确");request.getRequestDispatcher("/views/manage/manage_login.jsp").forward(request, response);}}
}

配置web.xml

<servlet><servlet-name>AdminServlet</servlet-name><servlet-class>com.zzw.furns.web.AdminServlet</servlet-class>
</servlet>
<servlet-mapping><servlet-name>AdminServlet</servlet-name><url-pattern>/adminServlet</url-pattern>
</servlet-mapping>

19.创建src/com/zzw/furns/web/FurnServlet.java, 家居显示Servlet

public class FurnServlet extends BasicServlet {private FurnService furnService = new FurnServiceImpl();protected void list(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {List<Furn> furns = furnService.queryFurn();//将结果保存到request域request.setAttribute("furns", furns);//请求转发到管理家具页面request.getRequestDispatcher("/views/manage/furn_manage.jsp").forward(request, response);}
}

配置web.xml

<servlet><servlet-name>FurnServlet</servlet-name><servlet-class>com.zzw.furns.web.FurnServlet</servlet-class>
</servlet>
<servlet-mapping><servlet-name>FurnServlet</servlet-name><url-pattern>/manage/furnServlet</url-pattern>
</servlet-mapping>

20.前端页面, web/views/manage/manage_login.jsp, 管理员登录页面

<span class="errorMsg"style="float: right; font-weight: bold; color: lightgray; font-size: 20pt; margin-left: 10px;">${msg}</span>
<%--管理员登陆--%>
<form action="adminServlet" method="post"><input type="hidden" name="action" value="login"/><input type="text" name="username" value="${username}" placeholder="Username"/><input type="password" name="password" placeholder="Password"/><div class="button-box"><div class="login-toggle-btn"><input type="checkbox"/><a class="flote-none" href="javascript:void(0)">Remember me</a><a href="#">Forgot Password?</a></div><button type="submit"><span>Login</span></button></div>
</form>

21.修改manage_menu.jsp, 家居菜单页面

22.修改furn_manage.jsp, 家居显示页面

<thead>
<tr><th>家居名</th><th>商家</th><th>价格</th><th>销量</th><th>库存</th><th>图片</th><th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${furns}" var="furn"><tr><td class="product-thumbnail"><a href="#"><img class="img-responsive ml-3"src="assets/images/product-image/1.jpg"alt=""/></a></td><td class="product-name"><a href="#">${furn.name}</a></td><td class="product-name"><a href="#">${furn.business}</a></td><td class="product-price-cart"><span class="amount">${furn.price}</span></td><td class="product-quantity">${furn.saleNum}</td><td class="product-quantity">${furn.inventory}</td><td class="product-remove"><a href="#"><i class="icon-pencil"></i></a><a href="#"><i class="icon-close"></i></a></td></tr>
</c:forEach>
</tbody>

23.测试

1)管理员登录

🌳添加家居

思路分析
1.请求添加家居, 请求FurnServlet的add方法, 将前端提交的数据封装到Furn对象
2.调用FurnService.add(Furn furn)方法
3.跳转到显示家居的页面

程序框架图

1.修改com.zzw.furns.FurnDAO

//添加Furn对象
public boolean add(Furn furn);

2.修改com.zzw.furns.impl.FurnDaoImpl

@Override
public boolean add(Furn furn) {String sql = "INSERT INTO furn(id, `name`, business, price, saleNum, inventory, image_path) " +"VALUES(NULL, ?, ?, ?, ?, ?, ?)";int updateRows = update(sql, furn.getName(), furn.getBusiness(), furn.getPrice(),furn.getSaleNum(), furn.getInventory(), furn.getImagePath());return updateRows > 0;
}

3.测试, 修改FurnDaoTest

@Test
public void add() {BigDecimal price = new BigDecimal(32.2);String imagePath = "assets/images/product-image/4.jpg";Furn furn =new Furn(null, "桌子", "南极人", price, 4500, 8000, imagePath);System.out.println(furnDAO.add(furn) ? "添加成功" : "添加失败");
}

4.修改com.zzw.furns.FurnService

//添加家居
public boolean addFurn(Furn furn);

/*** 添加家居** @param furn 前端传来的Furn对象* @return 返回布尔值*/
@Override
public boolean addFurn(Furn furn) {return furnDAO.add(furn);
}

5.修改com.zzw.furns.impl.FurnServiceImpl

/*** 添加家居** @param furn 前端传来的Furn对象* @return 返回布尔值*/
@Override
public boolean addFurn(Furn furn) {return furnDAO.add(furn);
}

6.测试,修改com.zzw.furns.impl.FurnServiceTest

/*** 添加家居** @param furn 前端传来的Furn对象* @return 返回布尔值*/
@Override
public boolean addFurn(Furn furn) {return furnDAO.add(furn);
}

7.工具类src/com/zzw/furns/utils/DataUtils.java

public class DataUtils {public static int parseInt(String str, Integer defaultValue) {try {int num = Integer.parseInt(str);return num;} catch (NumberFormatException e) {return defaultValue;}}
}

8.web层, 修改FurnServlet, 添加方法add

protected void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String name = req.getParameter("name");String business = req.getParameter("business");BigDecimal price = new BigDecimal(req.getParameter("price"));int saleNum = DataUtils.parseInt(req.getParameter("saleNum"), 0);int inventory = DataUtils.parseInt(req.getParameter("inventory"), 0);Furn furn = new Furn(null, name,business, price, saleNum, inventory, "assets/images/product-image/default.jpg");if (furnService.add(furn) > 0) {System.out.println("添加成功, 请求转发到list");//req.getRequestDispatcher("/manage/furnServlet?action=list")//        .forward(req, resp);resp.sendRedirect(req.getContextPath() + "/manage/furnServlet?action=list");} else {System.out.println("添加失败, 返回到添加页面");req.getRequestDispatcher("views/manage/furn_add.jsp").forward(req, resp);}
}

9.解决中文乱码问题
在BasicServlet中设置utf-8.

10.前端: furn_manage跳转到添加家居页面

<!-- Single Wedge Start -->
<div class="header-bottom-set dropdown"><a href="views/manage/furn_add.jsp">添加家居</a>
</div>

11.添加furn_add.jsp

<!--添加到table标签的下一行-->
<span class="errorMsg"style="float: right; font-weight: bold; color: lightgray; font-size: 20pt; margin-left: 10px;"></span>

12.测试

🍉解决重复添加

1.请求转发设置成重定向

🍉后端数据校验说明

后端方案一: 修改FurnServlet.java

String name = req.getParameter("name");
if (StringUtils.isEmpty(name)) {req.setAttribute("msg", "商品名不能为空");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}String business = req.getParameter("business");
if (StringUtils.isEmpty(business)) {req.setAttribute("msg", "商家不能为空");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}String saleNumTemp = req.getParameter("saleNum");
//不能为空
if (StringUtils.isEmpty(saleNumTemp)) {req.setAttribute("msg", "销量不能为空");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}String inventoryTemp = req.getParameter("inventory");
if (StringUtils.isEmpty(inventoryTemp)) {req.setAttribute("msg", "库存不能为空");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}String priceTemp = req.getParameter("price");
if (StringUtils.isEmpty(priceTemp)) {req.setAttribute("msg", "价格不能为空");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}Integer saleNum = null;
try {saleNum = Integer.parseInt(saleNumTemp);
} catch (NumberFormatException e) {req.setAttribute("msg", "销量格式错误");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}Integer inventory = null;
try {inventory = Integer.parseInt(inventoryTemp);
} catch (NumberFormatException e) {req.setAttribute("msg", "库存格式错误");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}BigDecimal price = null;
try {price = new BigDecimal(priceTemp);
} catch (NumberFormatException e) {req.setAttribute("msg", "价格格式错误");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);return;
}

前端数据校验, 修改web/views/manage/furn_add.jsp

<script src="script/jquery-3.6.0.min.js"></script>
<script type="text/javascript">window.onload = function () {$("input[type='submit']")[0].onclick = function () {if ($("input[name='name']").val() == "" || $("input[name='name']").val() == null) {alert("请输入家居名");return false;} else if ($("input[name='business']").val() == "" || $("input[name='business']").val() == null) {alert("请输入商家名");return false;} else if ($("input[name='price']").val() == "" || $("input[name='price']").val() == null) {alert("请输入价格");return false;} else if ($("input[name='saleNum']").val() == "" || $("input[name='saleNum']").val() == null) {alert("请输入销量");return false;} else if ($("input[name='inventory']").val() == "" || $("input[name='inventory']").val() == null) {alert("请输入库存");return false;}else if (!/^\d+(\.\d+)?$/.test($("input[name='price']").val())) {alert("价格格式不对");return false;} else if (!/^\d+$/.test($("input[name='saleNum']").val())) {alert("销量格式不对");return false;} else if (!/^\d+$/.test($("input[name='inventory']").val())) {alert("库存格式不对");return false;}}}
</script>

🍉BeanUtils自动封装Bean

1.引入jar包

2.修改src/com/zzw/furns/utils/DataUtils.java, 增加方法

//将方法, 封装到静态方法, 方便使用
public static <T> T copyParamToBean(Map value, T bean) {try {//req.getParameterMap() 将数据封装到furn对象// 底层使用反射封装数据// 前端的name属性值需要和javabean的属性名一致BeanUtils.populate(bean, value);} catch (Exception e) {throw new RuntimeException(e);}return bean;
}

3.修改src/com/zzw/furns/web/FurnServlet.java的add方法, 使用BeanUtils自动封装javabean

protected void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//这里我们使用第二种方式, 将前端提交的数据, 自动封装成Furn的Javabean对象//使用beanUtils完成javabean对象的自动封装Furn furn =DataUtils.copyParamToBean(req.getParameterMap(), new Furn());if (furnService.addFurn(furn)) {String pageNo = req.getParameter("pageNo");System.out.println("添加成功..");//req.getRequestDispatcher("/manage/furnServlet?action=list").forward(req, resp);resp.sendRedirect(req.getContextPath() + "/manage/furnServlet?action=list");} else {System.out.println("添加失败");req.setAttribute("errorMsg", "添加失败");req.getRequestDispatcher("/views/manage/furn_add.jsp").forward(req, resp);}}

debug小技巧👉

2.报错
原因: 由于前端没有传imagePath的字段, 所以后端在构建furn对象的时候, imagePath属性位null
解决方案👇

🌳删除家居

需求分析
1.管理员进入到家居管理页面
2.点击删除家居链接, 弹出确认窗口, 确认-删除, 取消-放弃

程序框架图

1.修改com.zzw.furns.FurnDAO

//根据id删除对应的furn对象
public boolean deleteFurnById(int id);

2.修改com.zzw.furns.impl.FurnDaoImpl

@Override
public boolean deleteFurnById(int id) {String sql = "DELETE FROM furn WHERE id = ?";int updateRows = update(sql, id);return updateRows > 0;
}

3.测试, 修改FurnDaoTest

@Test
public void deleteFurnById() {int id = 30;System.out.println("执行结果= " + furnDAO.deleteFurnById(id));
}

4.修改com.zzw.furns.FurnService

//根据id删除家居
public boolean deleteFurnById(int id);

5.修改com.zzw.furns.impl.FurnServiceImpl

@Override
public boolean deleteFurnById(int id) {return furnDAO.deleteFurnById(id);
}

6.测试,修改com.zzw.furns.impl.FurnServiceTest

@Test
public void deleteFurnById() {int id = 31;System.out.println("执行结果= " + furnService.deleteFurnById(id));
}

6.web层 - 修改src/com/zzw/furns/web/FurnServlet.java, 增加del方法

protected void del(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {int id = DataUtils.parseInt(req.getParameter("id"), 0);if (furnService.deleteFurnById(id) > 0) {System.out.println("删除成功");} else {System.out.println("删除失败");req.setAttribute("msg", "删除失败");}resp.sendRedirect(req.getContextPath() + "/manage/furnServlet?action=list");}

7.修改web/views/manage/furn_manage.jsp页面

<a furnName="${furn.name}" href="manage/furnServlet?action=del&id=${furn.id}"><i class="icon-close"></i>
</a>

jQuery操作父元素, 兄弟元素, 子元素, 请移步👉
js弹框请移步👉

<script src="scripts/jquery-3.6.0.js"></script>
<script type="text/javascript">window.onload = function () {$("a[furnName]").click(function () {var furnName = $(this).attr("furnName");//js弹框//1.window.confirm 方法会弹出一个确认窗口//2.点击确定, 返回true//3.点击取消, 返回falsevar b = window.confirm("你确认要删除 " + furnName+ " 家居信息吗?");if (!b) {return false;}//简便写法return window.confirm("你确认要删除 " + furnName+ " 家居信息吗?");//最终写法return confirm("你确定要删除 " + furnName + " 家居信息嘛?");});}
</script>

🌳修改家具

思路分析
1.管理员进入家居管理页面furn_manage.jsp
2.点击修改家居链接, 回显该家居信息 furn_update.jsp
3.填写新的信息, 点击修改家居按钮
4.修改成功后, 显示刷新后的家居列表

程序框架图

1.修改com.zzw.furns.FurnDAO

//根据id查询furn对象
public Furn queryFurnById(int id);//将传入的furn对象, 更新到数据库
public boolean updateFurn(Furn furn);

2.修改com.zzw.furns.impl.FurnDaoImpl

/*** 根据传来的id查询对应的Furn对象** @param id 参数* @return 返回查询到的Furn对象*/
@Override
public Furn queryFurnById(int id) {String sql = "SELECT id, `name`, business, price, saleNum, inventory, " +"image_path as imagePath FROM furn WHERE id = ?";Furn furn = querySingle(sql, Furn.class, id);return furn;
}/*** 根据id修改furn表对应的记录* @param furn 要修改的内容* @return 返回true或false*/
@Override
public boolean updateFurn(Furn furn) {String sql = "UPDATE furn SET `name`=?, business=?, price=?, saleNum=?, inventory=?, image_path=? WHERE id=?";int updateRows =update(sql, furn.getName(), furn.getBusiness(), furn.getPrice(), furn.getSaleNum(),furn.getInventory(), furn.getImagePath(), furn.getId());return updateRows > 0;
}

3.测试, 修改FurnDaoTest

@Test
public void queryFurnById() {int id = 75;Furn furn = furnDAO.queryFurnById(id);System.out.println(furn);
}@Test
public void updateFurn() {Furn furn = new Furn(5, "手机", "小米", new BigDecimal(3000), 6000, 9000, "zzw");furnDAO.updateFurn(furn);System.out.println();
}

4.修改com.zzw.furns.FurnService

//根据id查询家居
public Furn queryFurnById(int id);//根据id修改家居信息
public boolean updateFurn(Furn furn);

5.修改com.zzw.furns.impl.FurnServiceImpl

/*** 根据前端传来的id查询家居** @param id 参数* @return 返回查询到的家居*/
@Override
public Furn queryFurnById(int id) {Furn furn = furnDAO.queryFurnById(id);return furn;
}/*** 根据id修改家居信息** @param furn 要修改的内容* @return 返回true或false*/
@Override
public boolean updateFurn(Furn furn) {return furnDAO.updateFurn(furn);
}

6.测试,修改com.zzw.furns.impl.FurnServiceTest

@Test
public void queryFurnById() {int id = 75;Furn furn = furnService.queryFurnById(id);System.out.println(furn);
}@Test
public void updateFurn() {Furn furn = new Furn(75, "耳麦", "苹果", new BigDecimal(500),5000, 7000, "");System.out.println(furnService.updateFurn(furn));
}

7.web层 - 修改src/com/zzw/furns/web/FurnServlet.java, 增加display方法和update方法

protected void display(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {int id = DataUtils.parseInt(req.getParameter("id"), 0);Furn furn = furnService.queryFurnById(id);if (furn != null) {//将furn对象放入request域req.setAttribute("furn", furn);req.getRequestDispatcher("/views/manage/furn_update.jsp").forward(req, resp);} else {System.out.println("查询不到该信息");req.getRequestDispatcher("/manage/furnServlet?action=list").forward(req, resp);}
}protected void update(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Furn furn =DataUtils.copyParamToBean(req.getParameterMap(), new Furn());if (furnService.updateFurn(furn) > 0) {System.out.println("更新成功");resp.sendRedirect(req.getContextPath() + "/manage/furnServlet?action=list");} else {req.setAttribute("msg", "更新失败");req.getRequestDispatcher("/manage/furnServlet?action=display&id=" + furn.getId()).forward(req, resp);}
}

8.前端, 修改web/views/manage/furn_manage.jsp页面, 点击修改,发出请求

<a href="manage/furnServlet?action=display&id=${furn.id}"><i class="icon-pencil"></i>
</a>

9.添加web/views/manage/furn_update.jsp页面, 在tr标签下面添加span标签

<span class="errorMsg"style="float: right; font-weight: bold; color: lightgray; font-size: 20pt; margin-left: 10px;">${msg}</span>

10.修改web/views/manage/furn_update.jsp页面， 数据校验

<script src="script/jquery-3.6.0.min.js"></script>
<script type="text/javascript">window.onload = function () {$("input[type='submit']")[0].onclick = function () {if ($("input[name='name']").val() == "" || $("input[name='name']").val() == null) {alert("请输入家居名");return false;} else if ($("input[name='business']").val() == "" || $("input[name='business']").val() == null) {alert("请输入商家名");return false;} else if ($("input[name='price']").val() == "" || $("input[name='price']").val() == null) {alert("请输入价格");return false;} else if ($("input[name='saleNum']").val() == "" || $("input[name='saleNum']").val() == null) {alert("请输入销量");return false;} else if ($("input[name='inventory']").val() == "" || $("input[name='inventory']").val() == null) {alert("请输入库存");return false;}else if (!/^\d+(\.\d+)?$/.test($("input[name='price']").val())) {alert("价格格式不对");return false;} else if (!/^\d+$/.test($("input[name='saleNum']").val())) {alert("销量格式不对");return false;} else if (!/^\d+$/.test($("input[name='inventory']").val())) {alert("库存格式不对");return false;}}}
</script>

11.测试，修改数据,点击提交

这篇关于项目实战系列三: 家居购项目 第二部分的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---