Mybatis整合Servlet项目

今天药忘吃喽~ 2023-10-02 16:15 20阅读 0赞

**总目录 (最下面 Mybatis分页 扩展内容)**

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1. 如下图所式文件夹需要在**Mybatis逆向工程**中生成,有时间再说说Mybatis逆向工程

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2. **什么是 Open Session In View**

2.1 Open Session In View 模式：  
Open Session In View 是将一个数据库会话对象绑定到当前请求线程中，在请求期间一直  
保持数据库会话对象处于 Open 状态，使数据库会话对象在请求的整个期间都可以使用。直  
到产生响应后关闭当前的数据库会话对象。

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2.2 创建 OpenSqlSessionInViewFilter

package com.tong.web.filter;
    
    import com.tong.utils.MybatisUtils;
    import org.apache.ibatis.session.SqlSession;
    
    import javax.servlet.*;
    import javax.servlet.annotation.WebFilter;
    import java.io.IOException;
    
    /***
     * 在filter中打开一个SqlSession
     */
    @WebFilter("/*")
    public class OpenSqlSessionInViewFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
    
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            SqlSession sqlSession = MybatisUtils.getSqlSession();
            try
            {
                filterChain.doFilter(servletRequest, servletResponse);
                sqlSession.commit();
            }catch (Exception e)
            {
                e.printStackTrace();
                sqlSession.rollback();
            }finally{
                MybatisUtils.closeSqlSession();
            }
        }
    
        @Override
        public void destroy() {
    
        }
    }

**3. 完成业务操作**

**3.1添加用户**  
 **3.1.1 修改 index.jsp**

<%--
      Created by IntelliJ IDEA.
      User: 童蕴锐
      Date: 2021/7/29
      Time: 20:28
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
      <head>
        <title>首页</title>
      </head>
      <body>
         <a href="addUsers.jsp">添加用户</a>
      </body>
    </html>

**3.1.2 创建 addUsers.jsp**

<%--
      Created by IntelliJ IDEA.
      User: 童蕴锐
      Date: 2021/8/1
      Time: 19:50
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>添加用户</title>
    </head>
    <body>
        <form action="usersServlet.do" method="post">
            <input type="hidden" name="flag" value="addUsers"/>
            用户姓名:  <input type="text" name="username"/><br/>
            用户性别: <input type="text" name="userage"/><br>
            <input type="submit" value="OK"/>
        </form>
    </body>
    </html>

**3.1.3 创建 UsersServlet**

package com.tong.web.servlet;
    
    import com.tong.pojo.Users;
    import com.tong.service.UsersService;
    import com.tong.service.impl.UsersServiceImpl;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    
    @WebServlet("/usersServlet.do")
    public class UsersServlet extends HttpServlet {
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            this.doPost(req, resp);
        }
    
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            String flag = req.getParameter("flag");
            if("addUsers".equals(flag)){
                this.addUsers(req,resp);
            }
        }
        /**
         * 处理添加用户请求
         */
        private void addUsers(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
            Users users = this.createUsers(req);
            UsersService usersService = new UsersServiceImpl();
            usersService.addUsers(users);
            resp.sendRedirect("ok.jsp");
        }
        /**
         * 获取提交数据
         */
        private Users createUsers(HttpServletRequest req){
            String username = req.getParameter("username");
            String userage = req.getParameter("userage");
            Users users = new Users();
            users.setUsername(username);
            users.setUserage(Integer.valueOf(userage));
            return users;
        }
    
    }

**3.1.4 创建业务层**

package com.tong.service;
    
    import com.tong.pojo.Users;
    
    /**
     * @author 童蕴锐
     */
    public interface UsersService {
    
        void addUsers(Users users);
    }

package com.tong.service.impl;
    
    import com.tong.mapper.UsersMapper;
    import com.tong.pojo.Users;
    import com.tong.utils.MybatisUtils;
    import com.tong.service.UsersService;
    import org.apache.ibatis.session.SqlSession;
    
    public class UsersServiceImpl implements UsersService {
    
        /***
         * 添加用户
         * @param users
         */
        @Override
        public void addUsers(Users users) {
            SqlSession sqlSession = MybatisUtils.getSqlSession();
            UsersMapper usersMapper = sqlSession.getMapper(UsersMapper.class);
            usersMapper.insertSelective(users);
        }
    }

**3.1.5 创建成功页面**

<%--
      Created by IntelliJ IDEA.
      User: 童蕴锐
      Date: 2021/8/1
      Time: 20:36
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>Title</title>
    </head>
    <body>
         操作成功！！！
    </body>
    </html>

**3.2查询用户**  
**3.2.1 修改 index.jsp**

<%--
      Created by IntelliJ IDEA.
      User: 童蕴锐
      Date: 2021/8/1
      Time: 20:40
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
       <head>
            <title>$Title$</title>
       </head>
    <body>
    <a href="addUsers.jsp">添加用户</a>     <a href="findUsers.jsp">查询用户</a>
      </body>
    </html>

**3.2.2 创建 findUsers.jsp**

<%--
      Created by IntelliJ IDEA.
      User: 童蕴锐
      Date: 2021/8/1
      Time: 20:45
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
    <title>查询用户</title>
    </head>
    <body>
    <form action="usersServlet.do" method="post">
    <input type="hidden" name="flag" value="findUsers"/>
    用户姓名： <input type="text" name="username"/><br/>
    用户性别：<input type="text" name="usersex"/><br/>
    <input type="submit" value="OK"/>
    </form>
    </body>
    </html>

**3.2.3 修改 UsersServlet**

@WebServlet("/usersServlet.do")
    public class UsersServlet extends HttpServlet {
            @Override
    
      protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws 
      ServletException, IOException {
    
                      this.doPost(req, resp);
    }
            @Override
    
     protected void doPost(HttpServletRequest req,HttpServletResponse resp) throws 
     ServletException, IOException {
                     String flag = req.getParameter("flag");
    
                     if("addUsers".equals(flag)){
    
                     this.addUsers(req,resp);
    
                      }else if("findUsers".equals(flag)){
    
                        this.findUsers(req,resp);
    
                      }
    }
    
                   /**
                     * 处理添加用户请求
                   */
    
       private void addUsers(HttpServletRequest req, HttpServletResponse resp) throws 
       ServletException, IOException{
    
                   Users users = this.createUsers(req);
    
                   UsersService usersService = new UsersServiceImpl();
    
                   usersService.addUsers(users);
    
                   resp.sendRedirect("ok.jsp");
    }
    
                  /**
                    * 获取提交数据
                  */
    
       private Users createUsers(HttpServletRequest req){
    
                 String username = req.getParameter("username");
    
                 String usersex = req.getParameter("usersex");
    
                 Users users = new Users();
    
                 users.setUsername(username);
    
                 users.setUsersex(usersex);
    
                 return users;
    }
    
                 /**
                   * 查询用户
                 */
    
    private void findUsers(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
    
                    Users users = this.createUsers(req);
    
                    String pageIndex = req.getParameter("pageIndex");
    
                    int page = 1;
    
                    if(pageIndex != null && pageIndex.length() > 0){
    
                    page = Integer.parseInt(pageIndex);
    
                    }
    
                  UsersService usersService = new UsersServiceImpl();
    
                  PageInfo<Users> pageInfo = usersService.findUsers(page,users);
    
                  req.setAttribute("pageInfo",pageInfo);
    
                  req.setAttribute("users",users);
    
                  req.getRequestDispatcher("showUsers.jsp").forward(req,resp);
              }
    }

**3.2.4 修改业务层**

PageInfo<Users> findUsers(int page,Users users);

/**
                   * 查询用户
                   *
                 */
    
           @Override
    
        public PageInfo<Users> findUsers(int page, Users users) {
    
               SqlSession sqlSession = MybatisUtils.getSqlSession();
    
               UsersMapper usersMapper = sqlSession.getMapper(UsersMapper.class);
    
               UsersExample usersExample = this.createUsersExample(users);
    
               PageHelper.startPage(page,2);
    
               List<Users> list = usersMapper.selectByExample(usersExample);
    
               PageInfo<Users> pageInfo = new PageInfo<>(list);
    
               return pageInfo;
    }
    
                 /**
                   * 生成查询条件
                  */
           private UsersExample createUsersExample(Users users){
    
                 UsersExample usersExample = new UsersExample();
    
                 UsersExample.Criteria criteria = usersExample.createCriteria();
    
                if(users.getUsername() != null && users.getUsername().length() >0){
    
                         criteria.andUsernameEqualTo(users.getUsername());
    
                    }
    
                if(users.getUsersex() != null && users.getUsersex().length() > 0){
    
                        criteria.andUsersexEqualTo(users.getUsersex());
    
                    }
                         return usersExample;
    }

##  **扩 展 分 页** ##

**3.3.2 添加 taglib 指令标签**

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

**3.3.3 创显示查询结果页面**

<%--
      Created by IntelliJ IDEA.
      User: 童蕴锐
      Date: 2021/8/2
      Time: 20:45
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
    <html>
       <head>
              <title>显示查询结果</title>
        <script>
           function subForm(pageIndex){
                   document.getElementById("pageIndex").value=pageIndex;
                   document.forms[0].submit();
    }
        </script>
      </head>
    <body>
             <form action="usersServlet.do" method="post">
                  <input type="hidden" name="flag" value="findUsers"/>
                  <input type="hidden" name="pageIndex" id="pageIndex"/>
                  <input type="hidden" name="username" value="${users.username}"/>
                  <input type="hidden" name="usersex" value="${users.usersex}"/>
             </form>
    
    <table align="center" border="1" width="40%">
            <tr>
               <th>用户 ID</th>
               <th>用户姓名</th>
               <th>用户性别</th>
            </tr>
       <c:forEach items="${pageInfo.list}" var="users">
           <tr>
              <td>${users.userid}</td>
              <td>${users.username}</td>
              <td>${users.usersex}</td>
          </tr>
       </c:forEach>
    <tr>
        <td colspan="3" align="center">
        <c:if test="${pageInfo.pageNum > 1}">
           <a href="#" onclick="subForm(${pageInfo.pageNum - 1})">上一页</a>
        </c:if>
        <c:forEach begin="1" end="${pageInfo.pages}" varStatus="st">
       <c:choose>
            <c:when test="${pageInfo.pageNum eq st.count}">
              <a style="color: red" href="#" onclick="subForm(${st.count})">${st.count}</a>
            </c:when>
       <c:otherwise>
             <a href="#" onclick="subForm(${st.count})">${st.count}</a>
       </c:otherwise>
      </c:choose>
     </c:forEach>
    <c:if test="${pageInfo.pageNum < pageInfo.pages}">
    <a href="#" onclick="subForm(${pageInfo.pageNum + 1})">下一页</a>
                </c:if>
    
             </td>
    
          </tr>
    
       </table>
    
      </body>
    
    </html>

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