JavaEE三层结构——用户管理(添加用户)

以下操作只针对本案例，仅供参考！

一、数据库环境搭建

二、环境搭建

1、开发包

2、连接池配置文件

<c3p0-config>
   <!-- 使用默认的配置读取连接池对象 -->
   <default-config>
      <!--  1. 数据库的连接参数 -->
      <property name="driverClass">com.mysql.jdbc.Driver</property>
      <property name="jdbcUrl">jdbc:mysql:///casedemo</property>
      <property name="user">casedemo</property>
      <property name="password">123</property>

   </default-config>
</c3p0-config>

3、创建好所需要的包

在utils包里有一个C3p0Utils工具类

package cn.usermanager.utils;

import com.mchange.v2.c3p0.ComboPooledDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 数据源的工具类
 */
public class C3p0Utils {
    /**
     * 创建私有静态数据源成员变量
     */
    private static ComboPooledDataSource ds = new ComboPooledDataSource();

    /**
     * 创建公有的得到数据源的方法
     *
     * @return
     */
    public static DataSource getDataSource() {
        return ds;
    }

    /**
     * 创建得到连接对象的方法
     *
     * @return
     */
    public static Connection getConnection() {
        try {
            return ds.getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 创建释放资源的方法
     * @param conn
     * @param stmt
     * @param rs
     */
    public static void close(Connection conn, Statement stmt, ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void close(Connection conn, Statement stmt) {
        close(conn, stmt, null);
    }

    public static void main(String[] args) {
        System.out.println(getConnection());
    }


}

在domain包里创建实体类User

package cn.usermanager.domain;

public class User {
    private int id;
    private String name;
    private String sex;
    private String address;
    private String email;
    private String qq;
    private int age;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getQq() {
        return qq;
    }

    public void setQq(String qq) {
        this.qq = qq;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

3、导入所需要的页面原型

4、add.jsp form表单添加action="addUserServlet"

5、AddUserServlet.java接受表单用户信息

package cn.usermanager.web;

import cn.usermanager.domain.User;

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("/addUserServlet")
public class AddUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        //1、请求参数的封装  TO对象中
        String name = request.getParameter("name");
        String sex = request.getParameter("sex");
        String address = request.getParameter("address");
        String email = request.getParameter("email");
        String qq = request.getParameter("qq");
        String age = request.getParameter("age");
        User user = new User();
        user.setName(name);
        user.setSex(sex);
        user.setAddress(address);
        user.setEmail(email);
        user.setQq(qq);
        user.setAge(Integer.parseInt(age));

        //2、调用业务层
        UserService userService = new UserServiceImpl();
        User existUser = userService.addUser(user);

        //3、根据existUser ==null ？跳转到添加用户成功页面：添加页面+错误信息
        if (existUser == null) {
            response.sendRedirect("add_ok.jsp");
        }else{
            //email 冲突
            request.setAttribute("","邮箱已存在");
            request.getRequestDispatcher("/add.jsp").forward(request,response);
        }
    }
}

6、service接口和service实现类编写

package cn.usermanager.service.impl;

import cn.usermanager.domain.User;
import cn.usermanager.service.UserService;

public class UserServiceImpl implements UserService {
    private  UserDao userDao = new UserDaoImpl();
    @Override
    public User addUser(User user) {
        //业务逻辑 先根据邮箱查询 结果 再去做Insert操作
        User existUser = null;
        try {
            existUser =  userDao.findUserByEmail(user.getEmail());
        } catch (Exception e) {
            System.out.println("可以注册......dao实现添加用户操作");
            userDao.addUser(user);
        }
        return existUser;
    }
}

package cn.usermanager.service;

import cn.usermanager.domain.User;

public interface UserService {
    User addUser(User user);
}

7、dao接口和dao实现类的编写

package cn.usermanager.dao.impl;

import cn.usermanager.dao.UserDao;
import cn.usermanager.domain.User;
import cn.usermanager.utils.C3p0Utils;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

public class UserDaoImpl implements UserDao {
    @Override
    public User findUserByEmail(String email) {
        JdbcTemplate template = new JdbcTemplate(C3p0Utils.getDataSource());
        String sql = "select * from tab_user where email=?";
        User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), email);
        return user;

    }

    @Override
    public void addUser(User user) {
        JdbcTemplate template = new JdbcTemplate(C3p0Utils.getDataSource());
        String sql = "insert into tab_user values(null,?,?,?,?,?,?)";
        template.update(sql, user.getName(), user.getSex(), user.getAge(), user.getAddress(), user.getQq(), user.getEmail());
    }
}

package cn.usermanager.dao;

import cn.usermanager.domain.User;

public interface UserDao {
    User findUserByEmail(String email);

    void addUser(User user);
}

add_ok.jsp页面完善

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!-- HTML5文档-->
<!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">
</head>
<body>
    <center><h3>添加联系人页面</h3></center>
    <center><h3>恭喜你，添加员工成功！</h3></center>
    <a href="queryAllUserServlet">查询员工列表</a>&nbsp;
    <a href="add.jsp">继续添加。。。</a>
</body>
</html>

8、效果图

邮箱相同

数据库用户数据已添加