JavaWeb用户信息查看的登录、增删改查案例

冷不防 2023-09-23 15:40 160阅读 0赞

> 黑马JavaWeb案例整理记录

### 文章目录 ###

*  案例源码：
 *  一、需求
 *  二、设计
 *   *  1、技术选型
     *  2、数据库设计
 *  三、开发步骤
 *  四、详细过程
 *   *  1、创建web项目，部署tomcat，导入jar包
     *  2、编写首页index.jsp
     *  3、编写servlet、servie、daomain、dao
 *  五、案例升级实现
 *   *  1、实现内容
     *  2、list.jsp新增设计
     *  3、实现登录功能
     *   *  login.jsp设计
         *  LoginServlet编写
         *  UserDaoImpl语句
     *  4、实现添加功能
     *   *  add.jsp编写
         *  AddUserServlet编写
         *  userDaoImpl语句
     *  5、实现删除功能
     *   *  list.jsp修改
         *  DelUserServlet
         *  userDaoImpl增加语句
     *  6、修改功能实现
     *   *  list.jsp增加修改发送路径
         *  FindUserServlet编写
         *  update.jsp编写
         *  UpdateUserServlet编写
         *  UserServiceImpl实现方法
         *  UserDaoImpl实现方法
     *  7、删除选中功能
     *   *  list.jsp编写
         *  DelSelectServlet编写
         *  UserServiceImpl编写
         *  UserDaoImpl编写
     *  8、实现全选，全不选和提示是否删除框
     *   *  list.jsp编写实现
     *  9、分页查询功能（分页展示数据）
     *   *  改index.jsp路径
     *  10、多条件组合查询
 *  未完待续........

# 案例源码： #

# 一、需求 #

实现页面跳转和用户信息的增删改查操作

# 二、设计 #

## 1、技术选型 ##

Servlet+JSP+MySQL+JDBCTempleat+Duird+BeanUtilS+tomcat+BootStrap

## 2、数据库设计 ##

SQL语句

create database heima; -- 创建数据库
    			use heima; 			   -- 使用数据库
    			create table day17_user(   -- 创建表
    				id int primary key auto_increment,
    				name varchar(20) not null,
    				gender varchar(5),
    				age int,
    				address varchar(32),
    				qq	varchar(20),
    				email varchar(50)
    			);

# 三、开发步骤 #

1. 环境搭建
    		1. 创建数据库环境
    		2. 创建项目，导入需要的jar包
    
    2. 编码
    
    
    3. 测试
    4. 部署运维

**本笔记（不包含测试和运维）**

# 四、详细过程 #

![在这里插入图片描述][bec462af5f63470ca5f346b04c6e73a6.bmp]

## 1、创建web项目，部署tomcat，导入jar包 ##

jar包下载地址（里边有很多调出合适的）  
链接：https://pan.baidu.com/s/1V0X99u6U1zoDyFy2xm9Cyg  
提取码：h8sz  
![在这里插入图片描述][d91553eb120145cd8161b0d8b1434655.png]  
![在这里插入图片描述][6603c3e79939431b96880ef511044a84.png]  
![在这里插入图片描述][2dc1c7961cb748ceb11d8d851e7a57e6.png]

## 2、编写首页index.jsp ##

## 3、编写servlet、servie、daomain、dao ##

导入druid.properties，导入JDBCUtils类。源码都在源码链接中

# 五、案例升级实现 #

## 1、实现内容 ##

1.  列表查询
2.  登录
3.  添加
4.  删除
5.  修改

## 2、list.jsp新增设计 ##

按钮位置  
输入框  
分页条  
复选框

## 3、实现登录功能 ##

### login.jsp设计 ###

用到了checkCodeServlet，在我的其他博客写了，链接？？  
login.jsp点击切换验证码实现，如下图  
![在这里插入图片描述][cc12eec573b145f283d461d56e48edc7.png]

### LoginServlet编写 ###

@WebServlet(value = "/loginServlet")
    public class LoginServlet extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            this.doPost(request, response);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //1.设置编码
            request.setCharacterEncoding("utf-8");
            //2.获取数据
            //2.1获取用户填写验证码
            String verifycode = request.getParameter("verifycode");
            //3.验证码校验
            HttpSession session = request.getSession();
            String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
            session.removeAttribute("CHECKCODE_SERVER");
    
            //忽略大小写判断相等
            if (!checkcode_server.equalsIgnoreCase(verifycode)){
        
                //盐城吗不正确
                //提示信息
                request.setAttribute("login_msg", "验证码错误！");
                //跳转登录页面
                request.getRequestDispatcher("/login.jsp").forward(request,response);
    
                return;
            }
    
            Map<String, String[]> map = request.getParameterMap();
            //4.封装User对象
            User user = new User();
            try {
        
                BeanUtils.populate(user, map);
            }catch (IllegalAccessException e){
        
                e.printStackTrace();
            }catch (InvocationTargetException e){
        
                e.printStackTrace();
            }
    
            //5.调用Srvice查询
            UserService service = new UserServiceImpl();
            User loginUser = service.login(user);
    
            //6.判断是否登录成功
            if(loginUser != null){
        
                //登录成功
                //将用户存入session
                session.setAttribute("user",loginUser);
                //跳转页面
                response.sendRedirect(request.getContextPath()+"/index.jsp");
            }else{
        
                //登录失败
                //提示信息
                request.setAttribute("login_msg","用户名或密码错误！");
                //跳转登录页面
                request.getRequestDispatcher("/login.jsp").forward(request,response);
    
            }
        }
    }

### UserDaoImpl语句 ###

/**
         * 登录账号
         * @param username
         * @param password
         * @return
         */
        @Override
        public User findUserByUsernameAndPassword(String username, String password) {
        
    
            try {
        
                String sql = "select * from day17_user where username = ? and password= ?";
                User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), username, password);
                return user;
            } catch (Exception e) {
        
                e.printStackTrace();
                return null;
            }
        }

## 4、实现添加功能 ##

![在这里插入图片描述][3828b3ca0a54424baf1d41ee479e2648.bmp]

### add.jsp编写 ###

**源码在顶部链接**  
注意事项：提交路径  
![在这里插入图片描述][a14efae378034c4ba33bd95e080e96cb.png]

### AddUserServlet编写 ###

@WebServlet(value = "/addUserServlet")
    public class AddUserServlet extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            this.doPost(request, response);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //1.设置编码
            request.setCharacterEncoding("utf-8");
            //2.获取参数
            Map<String, String[]> map = request.getParameterMap();
            //3.封装对象
            User user = new User();
            try {
        
                BeanUtils.populate(user, map);
            } catch (IllegalAccessException e) {
        
                e.printStackTrace();
            } catch (InvocationTargetException e) {
        
                e.printStackTrace();
            }
            //4.调用Service保存
            UserService service = new UserServiceImpl();
            service.addUser(user);
    
            //5.跳转到userListServlet
            response.sendRedirect(request.getContextPath()+"/userListServlet");
        }
    }

### userDaoImpl语句 ###

/**
         * 添加user
         * @param user
         */
        @Override
        public void add(User user) {
        
            String sql = "insert into day17_user values(null,?,?,?,?,?,?,null,null)";
    //        template.update(sql, user.getName(), user.getGender(), user.getAge(), user.getAddress(), user.getQq(), user.getEmail());
            template.update(sql, user.getName(), user.getGender(), user.getAge(), user.getAddress(), user.getQq(), user.getEmail());
        }

## 5、实现删除功能 ##

![在这里插入图片描述][86e51692408642ecb6c93d320ff82d44.bmp]

### list.jsp修改 ###

![在这里插入图片描述][825b2dffdf954885840aa9b24ec09245.png]

### DelUserServlet ###

@WebServlet("/delUserServlet")
    public class DelUserServlet extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            this.doPost(request, response);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //1.获取id
            String id =request.getParameter("id");
            //2.调用service删除
            UserService service = new UserServiceImpl();
            service.deleteUser(id);
            //3.跳转到查询所有Servlet
            response.sendRedirect(request.getContextPath()+"/userListServlet");
    
        }
    }

### userDaoImpl增加语句 ###

/**
         * 根据id删除
         * @param id
         */
        @Override
        public void delete(int id) {
        
            String sql = "delete from day17_user where id = ?";
            template.update(sql,id);
        }

## 6、修改功能实现 ##

![在这里插入图片描述][afe7d996efe141c8a1fa5b52082a1304.bmp]  
注意：隐藏域提交id。下面内容会提到

### list.jsp增加修改发送路径 ###

![在这里插入图片描述][88a78ee6da03403e83d87537fa75250f.png]

### FindUserServlet编写 ###

@WebServlet(value = "/findUserServlet")
    public class FindUserServlet extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            this.doPost(request, response);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //1.获取id
            String id = request.getParameter("id");
            //2.调用Service查询
            UserService service = new UserServiceImpl();
            User user = service.findUserBuId(id);
            //3.将user存入request
            request.setAttribute("user",user);
            //4.转发到update.jsp
            request.getRequestDispatcher("/update.jsp").forward(request,response);
        }
    }

![在这里插入图片描述][5dda3ed067c74c819f019b029cd368f0.png]

### update.jsp编写 ###

id提交隐藏域如下  
![在这里插入图片描述][9dcdb31ed016458787a3a162a0058ff1.png]  
以下注意地点举例，具体请查看开篇源码链接。  
![在这里插入图片描述][d855b0400068485790ea4790036273fd.png]  
![在这里插入图片描述][95fb88fe557b469fbdfd72de65677370.png]  
![在这里插入图片描述][0980f3b65c084ff5a8b12d7a5bd16fcd.png]

### UpdateUserServlet编写 ###

@WebServlet(value = "/updateUserServlet")
    public class UpdateUserServlet extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            this.doPost(request, response);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //1.设置编码
            request.setCharacterEncoding("utf-8");
            //2.获取map
            Map<String, String[]> map = request.getParameterMap();
            //3.封装对象
            User user  = new User();
            try {
        
                BeanUtils.populate(user, map);
            } catch (IllegalAccessException e) {
        
                e.printStackTrace();
            } catch (InvocationTargetException e) {
        
                e.printStackTrace();
            }
            //4.调用Service修改
            UserService service = new UserServiceImpl();
            service.updateUser(user);
            //5.跳转到查询所有Servlet
            response.sendRedirect(request.getContextPath()+"/userListServlet");
        }
    }

### UserServiceImpl实现方法 ###

![在这里插入图片描述][7715e40257b347cbbfd12474a92cf981.png]

### UserDaoImpl实现方法 ###

![在这里插入图片描述][e9808083e599429fb38cbfc15a1d7e19.png]

## 7、删除选中功能 ##

![在这里插入图片描述][44461412a612444daec068d532e1cae2.bmp]

### list.jsp编写 ###

![在这里插入图片描述][55fb06134edb4225abb390164881f7ea.png]  
![在这里插入图片描述][7e8cf25c9d3f40e59bfca713c0972877.png]

### DelSelectServlet编写 ###

@WebServlet(value = "/delSelectServlet")
    public class DelSelectServlet extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            this.doPost(request, response);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //1.获取所有id
            String[] ids = request.getParameterValues("uid");
            //
            UserService service = new UserServiceImpl();
            service.delSelectUser(ids);
            //
            response.sendRedirect(request.getContextPath()+"/userListServlet");
        }
    }

### UserServiceImpl编写 ###

@Override
        public void delSelectUser(String[] ids) {
        
            //判断有东西才删除，否则会空指针异常
            if (ids != null && ids.length>0){
        
                //1.遍历数组
                for (String id : ids){
        
                    //2.2.调用dao删除
                    dao.delete(Integer.parseInt(id));
                }
            }
    
        }

### UserDaoImpl编写 ###

还是用之前写的，不过就是上一步的service将选中的id列表挨个遍历传进来，挨个删除，还是用以前的方法

## 8、实现全选，全不选和提示是否删除框 ##

### list.jsp编写实现 ###

![在这里插入图片描述][657dd842c9284a95895650ef52942948.png]  
有选中条目才提交删除  
![在这里插入图片描述][239f9913d9714d43af4120e802319910.png]  
同样Service中也要判断一下提交的里边有无内容，不判断的话有时候会空指针异常  
![在这里插入图片描述][66496eee63084f98876bb2339dc6fe18.png]

## 9、分页查询功能（分页展示数据） ##

![在这里插入图片描述][f6ac535f465d4c19971ef06a29a8e45a.bmp]  
![在这里插入图片描述][c0a17bd0119f4f99850e1f361a671108.bmp]

### 改index.jsp路径 ###

![在这里插入图片描述][55326ce9fab342f7973555128dd25c28.png]

## 10、多条件组合查询 ##

![在这里插入图片描述][4ed34671a0e048c7b4f8e0571da00100.bmp]

# 未完待续… #

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