分层思想+mybatis相关的集成 - yuanse - 博客园 (cnblogs.com)
test6602
先把一些固定的配置文件先导入进来，比如说像mybatis-config.xml、mysql.properties等(自己根据需要修改)
1.UserMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!--<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"-->
<!-- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"-->
<!-- xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"-->
<!-- version="4.0">-->
<!--</web-app>-->
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace:命名空间-->
<mapper namespace = "com.xxxx.mapper.UserMapper">
<!-- id:对应Dao层接口方法名 paraterType:指定输入参数类型 -->
<!-- userGeneratedKeys="true"把新增加的主键赋值到自己定义的keyProperty(id)中-->
<select id="queryUserByName" parameterType="String" resultType="com.xxxx.entity.User">
select * from tb_user where uname = #{uname}
</select>
</mapper>
2.UserMapper.java
package com.xxxx.mapper;
import com.xxxx.entity.User;
/**
*用户接口类
*/
public interface UserMapper {
public User queryUserByName(String uname);
}
3.GetSqlSession.java
package com.xxxx.util;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class GetSqlSession {
/**
* 获取SqlSession对象
*/
public static SqlSession createSqlSession(){
SqlSessionFactory sqlSessionFactory=null;
InputStream input=null;
SqlSession session=null;
try{
//获取mybatis的环境配置文件 注意路径
String resource = "mybatis-config.xml";
//以流的方式获取resource(mybatis的环境配置文件)
input = Resources.getResourceAsStream(resource);
//创建会话工厂
sqlSessionFactory = new SqlSessionFactoryBuilder().build(input);
//通过工厂得到SqlSession
session = sqlSessionFactory.openSession();
return session;
}catch(IOException e){
e.printStackTrace();
return null;
}
}
//测试：能出结果，就配置完成了
// public static void main(String[] args) {
// System.out.println(createSqlSession());
// }
}
4.mybatis-config.xml
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--
properties 标签中的配置可以供整个配置文件使用，在任何位置都可以引入其中配置的值。
properties 标签可以通过子标签 property 标签来配置一些子元素信息，也可以配置外部的动态文件。
-->
<properties resource="mysql.properties"/>
<!-- 也可以配置 url，但是 url和resource只能存在一个 -->
<!-- 类型别名 -->
<!-- <typeAliases>-->
<!-- <typeAlias type="com.xxxx.entity.User" alias="User"/>-->
<!-- </typeAliases>-->
<!-- 对事物的管理和连接池的配置 -->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<!--mappers映射器-->
<mappers>
<!--映射文件方式1.一个一个的配置-->
<!-- <mapper resource="com/xxxx/mapper/UserMapper.xml"/>-->
<!-- <mapper class="com.xxxx.mapper.UserMapper"/>-->
<!--映射文件方式2.自动扫描包内的Mapper接口和配置文件-->
<package name="com.xxxx.mapper"/>
</mappers>
</configuration>
5.mysql.properties
driver=com.mysql.cj.jdbc.Driver url=jdbc:mysql://127.0.0.1:3306/course?serverTimezone=UTC&useSSL=false&characterEncoding=UTF-8 username=root password=123456
6.Test.java(可要可不要，用来测试)
package com.xxxx.test;
import com.xxxx.entity.User;
import com.xxxx.mapper.UserMapper;
import com.xxxx.util.GetSqlSession;
import org.apache.ibatis.session.SqlSession;
public class Test {
public static void main(String[] args) {
//获取 SqlSession对象
SqlSession session = GetSqlSession.createSqlSession();
//得到对应的Mapper
UserMapper userMapper = session.getMapper(UserMapper.class);
//调用方法，返回用户对象
User user = userMapper.queryUserByName("admin");
System.out.println(user);
}
}
7.StringUtil.java(因为经常要判断字符串是否为空)
package com.xxxx.util;
/**
* 字符串工具类
*/
public class StringUtil {
//判断字符串是否为空注意：要写static
public static boolean isEmpty(String str){
if(str==null||"".equals(str.trim())){
return true;
}
return false;
}
}
8.User.java(实体类)
package com.xxxx.entity;
/**
* 用户实体类
*/
public class User {
private Integer uid;//用户编号
private String uname;//用户名字
private String upwd;//用户密码
private Integer uage;//用户年龄
public User(Integer uid, String uname, String upwd, Integer uage) {
this.uid = uid;
this.uname = uname;
this.upwd = upwd;
this.uage = uage;
}
public User() {
}
public Integer getUid() {
return uid;
}
public void setUid(Integer uid) {
this.uid = uid;
}
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getUpwd() {
return upwd;
}
public void setUpwd(String upwd) {
this.upwd = upwd;
}
public Integer getUage() {
return uage;
}
public void setUage(Integer uage) {
this.uage = uage;
}
}
9.MessageModel.java(消息模型实体类)
package com.xxxx.entity.vo;
/**
* 消息模型对象（做数据响应的）
* 状态码：
* 1=成功 0=失败
* 提示信息：
* 字符串
* 回显数据：
* object对象
*/
public class MessageModel {
private Integer code = 1;//状态码默认
private String msg = "成功";//提示信息
private Object object;//回显对象（）
public Integer getCode() {
return code;
}
public void setCode(Integer code) {
this.code = code;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
public Object getObject() {
return object;
}
public void setObject(Object object) {
this.object = object;
}
}
10.UserServlet.java
package com.xxxx.controller;
import com.xxxx.entity.vo.MessageModel;
import com.xxxx.service.UserService;
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("/loginServlet")
public class UserServlet extends HttpServlet {
//实例化UserService对象
private UserService userService = new UserService();
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取jsp表单信息 1.接收参数
String uname = request.getParameter("uname");
String upwd = request.getParameter("upwd");
//2.调用Service层方法，返回消息模型对象
MessageModel messageModel = userService.userlogin(uname,upwd);
//3.判断消息模型的状态码
if(messageModel.getCode()==1){
//成功：将消息模型中的用户消息设置到session作用域中，重定向跳转到index.jsp
request.getSession().setAttribute("user",messageModel.getObject());
//重定向
response.sendRedirect("index.jsp");
}else{
//将整个消息模型设置到request作用域中，请求转发到login.jsp中
request.setAttribute("messageModel",messageModel);
request.getRequestDispatcher("login.jsp").forward(request,response);
}
}
}
11.UserService.java
package com.xxxx.service;
import com.xxxx.entity.User;
import com.xxxx.entity.vo.MessageModel;
import com.xxxx.mapper.UserMapper;
import com.xxxx.util.GetSqlSession;
import com.xxxx.util.StringUtil;
import org.apache.ibatis.session.SqlSession;
/**
* 业务逻辑
*/
public class UserService {
public MessageModel userlogin(String uname,String upwd) {
MessageModel messageModel = new MessageModel();
//设置回显数据
User u = new User();
u.setUname(uname);
u.setUpwd(upwd);
messageModel.setObject(u);
//1.参数的非空判断（建议写个工具类，因为要经常调用）
if(StringUtil.isEmpty(uname)||StringUtil.isEmpty(upwd)){
//设置状态码等信息
messageModel.setCode(0);
messageModel.setMsg("用户姓名和密码不能为空");
return messageModel;
}
//2.调用dao层的查询方法，通过用户名查询用户对象
SqlSession session = GetSqlSession.createSqlSession();
UserMapper userMapper = session.getMapper(UserMapper.class);
User user = userMapper.queryUserByName(uname);
//3.判断用户对象是否为空
if(user==null){
messageModel.setCode(0);
messageModel.setMsg("用户不存在");
return messageModel;
}
//4.比较密码
if(!upwd.equals(user.getUpwd())){
messageModel.setCode(0);
messageModel.setMsg("用户密码不正确");
return messageModel;
}
//5.如果走到这一步，就说明前面都没有错，登录成功->将用户信息设置到消息模型中
messageModel.setObject(user);
return messageModel;
}
}
12.login.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录页面</title>
</head>
<body>
<div align="center">
<form method="post" action="loginServlet" id="loginForm" >
姓名：<input type="text" name="uname" id="uname" value="${messageModel.object.uname}"><br>
密码：<input type="password" name="upwd" id="upwd" value="${messageModel.object.upwd}"><br>
<span id="msg" style="font-size: 12px;color: red">${messageModel.msg}</span><br>
<button type="button" id="loginBtn">登录</button>
<button type="button">注册</button><br>
</form>
</div>
</body>
<script type="text/javascript" src="js/jquery-3.6.1.js"></script>
<script type="text/javascript">
$("#loginBtn").click(function(){
var uname=$("#uname").val();
var upwd=$("#upwd").val();
if(isEmpty(uname)){
$("#msg").html("用户姓名不能为空");
return;
}
if(isEmpty(upwd)){
$("#msg").html("用户密码不能为空");
return;
}
$("#loginForm").submit();
}
);
function isEmpty(str){
if(str==null||str.trim()==""){
return true;
}
return false;
}
</script>
</html>
13.index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<h2>欢迎${user.uname}登录成功</h2>
</body>
</html>
标签：02,return,String,登录,uname,实例,import,com,public From： https://www.cnblogs.com/hmy22466/p/16819519.html