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

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

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

LoginServlet编写

@WebServlet(value = "/loginServlet")
public class LoginServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}@Overrideprotected 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 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sessionsession.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*/@Overridepublic 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.class), username, password);return user;} catch (Exception e) {e.printStackTrace();return null;}}

4、实现添加功能

add.jsp编写

源码在顶部链接
注意事项：提交路径

AddUserServlet编写

@WebServlet(value = "/addUserServlet")
public class AddUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1.设置编码request.setCharacterEncoding("utf-8");//2.获取参数Map 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userListServletresponse.sendRedirect(request.getContextPath()+"/userListServlet");}
}

userDaoImpl语句

/*** 添加user* @param user*/@Overridepublic 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

list.jsp修改

DelUserServlet

@WebServlet("/delUserServlet")
public class DelUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1.获取idString 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Servletresponse.sendRedirect(request.getContextPath()+"/userListServlet");}
}

userDaoImpl增加语句

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

6、修改功能实现

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

修改

FindUserServlet编写

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

update.jsp编写

id提交隐藏域如下

以下注意地点举例，具体请查看开篇源码链接。

UpdateUserServlet编写

@WebServlet(value = "/updateUserServlet")
public class UpdateUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1.设置编码request.setCharacterEncoding("utf-8");//2.获取mapMap 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Servletresponse.sendRedirect(request.getContextPath()+"/userListServlet");}
}

UserServiceImpl实现方法

UserDaoImpl实现方法

7、删除选中功能

list.jsp编写

DelSelectServlet编写

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

UserServiceImpl编写

 @Overridepublic 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

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

8、实现全选，全不选和提示是否删除框

list.jsp编写实现

有选中条目才提交删除

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

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…