先简单建一个springboot项目试试,看看运行以后,localhost:8080能否进入,还有maven包是否已经导入。
1.按照目录,依次将包建好,我的项目名叫test。
2.bean包内建立“Userbean”
package com.example.test.bean;
public class UserBean {
private int id;
private String name;
private String password;
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 getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
3.controller包内建立"LoginController"
package com.example.test.controller;
import com.example.test.bean.UserBean;
import com.example.test.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
public class LoginController {
//将Service注入Web层
@Autowired
UserService userService;
@RequestMapping("/login")
public String show(){
return "login";
}
@RequestMapping(value = "/loginIn",method = RequestMethod.POST)
public String login(String name,String password){
UserBean userBean = userService.loginIn(name,password);
if(userBean!=null){
return "success";
}else {
return "error";
}
}
}
4.mapper文件夹下建立"Usermapper"(DAO层访问数据库接口文件: )
package com.example.test.mapper;
import com.example.test.bean.UserBean;
public interface UserMapper {
UserBean getInfo(String name,String password);
}
5.service文件夹下建立"Userservice"(Service层业务实现类编写,注意要注解@Service,注入DAO)
package com.example.test.service;
import com.example.test.bean.UserBean;
public interface UserService {
UserBean loginIn(String name,String password);
}
6.ServiceImpl文件夹下建立"UserServiceImpl"
package com.example.test.serviceImpl;
import com.example.test.bean.UserBean;
import com.example.test.mapper.UserMapper;
import com.example.test.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class UserServiceImpl implements UserService {
//将DAO注入Service层
@Autowired
private UserMapper userMapper;
@Override
public UserBean loginIn(String name, String password) {
return userMapper.getInfo(name,password);
}
}
7.启动java的TestApplication(项目启动类要添加注解@MapperScan项目启动时扫描mapper接口,否则会报错找不到mapper文件)
package com.example.test;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.test.mapper")
public class TestApplication {
public static void main(String[] args) {
SpringApplication.run(TestApplication.class, args);
}
}
8.在下面的resources文件夹下要再建立一个mapper文件夹,里面建立Usermapper.xml(xml第一行不能空,不然会报错)
(DAO层访问数据库实现文件(需在resource包下创建mapper文件夹,然后再创建一个UserMapper.xml.在application配置文件中mybatis:mapper-locations:对应的就是该文件地址),注意标签的namespace属性要填写 访问数据库接口类文件路径:)
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.example.test.mapper.UserMapper">
<select id="getInfo" parameterType="String" resultType="com.example.test.bean.UserBean">
SELECT * FROM user WHERE name = #{
name} AND password = #{
password}
</select>
</mapper>
9.下面的application.yml如果不是yml格式,可以先右键Refactor然后Rename修改为yml格式
然后代码如下:(url都是一样的,不同于在你的数据库名,用户名和密码基本都是root,123456,不过也得看你自己的。数据库驱动一定要加,如果报错,更新maven包试试)
spring:
datasource:
name: test #数据库名
url: jdbc:mysql://localhost:3306/test #url
username: root #用户名
password: 123456 #密码
driver-class-name: com.mysql.jdbc.Driver #数据库链接驱动
mybatis:
mapper-locations: classpath:mapper/*.xml #配置映射文件
type-aliases-package: com.example.test.bean #配置实体类
10.最后在temlplates添加login.html success.html error.html 即可
<html lang="en">
<head>
<meta charset="UTF-8">
<title>logintitle>
head>
<body>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>successtitle>
head>
<body>
<h1>登录成功!h1>
body>
html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>errortitle>
head>
<body>
<h1>登录失败!h1>
body>
html>
SpringBoot项目大概分为四层:
(1)DAO层:包括XxxMapper.java(数据库访问接口类),XxxMapper.xml(数据库链接实现);(这个命名,有人喜欢用Dao命名,有人喜欢用Mapper,看个人习惯了吧)
(2)Bean层:也叫model层,模型层,entity层,实体层,就是数据库表的映射实体类,存放POJO对象;
(3)Service层:也叫服务层,业务层,包括XxxService.java(业务接口类),XxxServiceImpl.java(业务实现类);(可以在service文件夹下新建impl文件放业务实现类,也可以把业务实现类单独放一个文件夹下,更清晰)
(4)Web层:就是Controller层,实现与web前端的交互
最后附上学习的博主文章(写的是真滴好)
https://blog.csdn.net/baidu_39298625/article/details/98102453?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4.control&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4.control