删除功能分析和代码实现

删除功能分析

list.jsp:

<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>

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

<!DOCTYPE html>
<!-- 网页使用的语言 -->
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>

    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
    <%-- 删除指定id   --%>
    <script>
        function deleteUser(id) {
            //用户安全提示
            if (confirm("确定要删除吗?")){
                //访问路径
                location.href = "${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }
    </script>

</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left">

        <form class="form-inline">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" class="form-control" id="exampleInputName2" placeholder="李四">
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">籍贯</label>
                <input type="email" class="form-control" id="exampleInputEmail2" placeholder="北京">
            </div>

            <div class="form-group">
                <label for="exampleInputEmail3">邮箱</label>
                <input type="email" class="form-control" id="exampleInputEmail3" placeholder="">
            </div>

            <button type="submit" class="btn btn-default">查询</button>
        </form>

    </div>

    <div style="float: right; margin: 5px">

            <td colspan="8" align="center"><a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a></td>
            <td colspan="8" align="center"><a class="btn btn-primary" href="add.html">删除选中</a></td>

    </div>


    <table border="1" class="table table-bordered table-hover">
        <tr class="success">
            <th><input type="checkbox"></th>
            <th>编号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>籍贯</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>

        <c:forEach items="${users}" var="user" varStatus="s">
            <tr>
                <td><input type="checkbox"></td>
                <td>${s.count}</td>
                <td>${user.name}</td>
                <td>${user.gender}</td>
                <td>${user.age}</td>
                <td>${user.address}</td>
                <td>${user.qq}</td>
                <td>${user.email}</td>
                <td>
                    <a class="btn btn-default btn-sm" href="update.html">修改</a> 

                    <%--<a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/delUserServlet?id=${user.id}">删除</a>--%>
                    <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id})">删除</a>

                </td>
            </tr>
        </c:forEach>
    </table>
    <div>

        <nav aria-label="Page navigation">
            <ul class="pagination">
                <li>
                    <a href="#" aria-label="Previous">
                        <span aria-hidden="true">«</span>
                    </a>
                </li>
                <li><a href="#">1</a></li>
                <li><a href="#">2</a></li>
                <li><a href="#">3</a></li>
                <li><a href="#">4</a></li>
                <li><a href="#">5</a></li>
                <li>
                    <a href="#" aria-label="Next">
                        <span aria-hidden="true">»</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px">
                    共15条记录，共4页

                </span>
            </ul>
        </nav>
    </div>


</div>
</body>
</html>

UserDao接口：

package com.example.dao;

import com.example.domain.User1;

import java.util.List;

/**
 * 用户操作的dao
 */
public interface UserDao {
    public List<User1> findAll();

    public User1 findUserByUsernameAndPassword(String username,String password);

    void add(User1 user1);


    void delete(int id);
}

UserDaoImpl类：

package com.example.dao.impl;

import com.example.dao.UserDao;
import com.example.domain.User1;
import com.example.util.JDBCUtils;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.List;

public class UserDaoImpl  implements UserDao {

    private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());

    @Override
    public List<User1> findAll() {
        //实现JDBC数据库操作
        //定义sql
        String sql = "select * from user1";
        List<User1> users = template.query(sql, new BeanPropertyRowMapper<User1>(User1.class));
        return users;

    }

    @Override
    public User1 findUserByUsernameAndPassword(String username, String password) {

        try {
            String sql = "select * from user1 where username = ? and password = ?";
            User1 user1 = template.queryForObject(sql, new BeanPropertyRowMapper<User1>(User1.class), username, password);
            return user1;
        } catch (DataAccessException e) {
            e.printStackTrace();
            return null;
        }
    }

    @Override
    public void add(User1 user1) {
        //1.定义sql
        String sql = "insert into user1 value(null,?,?,?,?,?,?,null,null)";
        //2.执行sql
        template.update(sql,user1.getName(),user1.getGender(),user1.getAge(),user1.getAddress(),user1.getQq(),user1.getEmail());
    }

    @Override
    public void delete(int id) {
        //1.定义sql
        String sql = "delete from user1 where id = ?";
        template.update(sql, id);
    }
}

UserService接口：

package com.example.service;

import com.example.domain.User1;

import java.util.List;

public interface UserService {
    /**
     * 查询方法
     * @return
     */
    public List<User1> findAll();

    /**
     * 登录方法
     * @param user1
     * @return
     */
    User1 login(User1 user1);

    /**
     * 添加User1
     * @param user1
     */
    void addUser(User1 user1);

    /**
     * 根据id删除User1
     * @param id
     */
    void deleteUser(String id);
}

UserServiceImpl类：

package com.example.service.impl;

import com.example.dao.UserDao;
import com.example.dao.impl.UserDaoImpl;
import com.example.domain.User1;
import com.example.service.UserService;

import java.util.List;

public class UserServiceImpl  implements UserService {

    public UserDao dao = new UserDaoImpl();

    @Override
    public List<User1> findAll() {
        //调用dao完成查询
        return dao.findAll();
    }

    @Override
    public User1 login(User1 user1) {
        return dao.findUserByUsernameAndPassword(user1.getUsername(),user1.getPassword());
    }

    @Override
    public void addUser(User1 user1) {
        dao.add(user1);
    }

    @Override
    public void deleteUser(String id) {
        dao.delete(Integer.parseInt(id));//转换为int类型
    }
}

DelUserServlet类：

package com.example.web.servlet;

import com.example.service.UserService;
import com.example.service.impl.UserServiceImpl;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet(name = "delUserServlet", value = "/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.获取参数，id
        String id = request.getParameter("id");
        //2.调用service删除
        UserService service = new UserServiceImpl();
        service.deleteUser(id);
        //3.跳转查询所有Servlet
        response.sendRedirect(request.getContextPath()+"/userListServlet");
    }
}