学习过程主要参考了
新建一个SpringBoot项目
点击next,修改项目名:
点击next,选择需要的依赖:
确认项目名称和路径后点击finish。
配置maven
(1)选择本地Maven路径(2)勾选配置文件后的选项,修改为本地Maven的配置文件,它会根据配置文件直接找到本地仓库位置
配置完成后点击下载按钮下载源文件和文档
编写文件
在templates文件夹下新建index.html文件作为初始页面
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>云会议</title>
</head>
<body>
hello!
</body>
</html>
在com.example.study下新建controller文件夹,在controller文件夹下新建一个helloController类(Controller类要添加@Controller注解,项目启动时,SpringBoot会自动扫描加载Controller)
package com.example.study.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class helloController {
@RequestMapping("/index")
public String sayHello(){
return "index";
}
}
在resources文件夹下的application文件中配置DataSource基本信息,application文件有两种文件格式,一种以.properties为后缀,一种以.yml为后缀,两种配置方式略有差别,详情参考:
这里选择以.properties为后缀:
spring.datasource.name=study
spring.datasource.url=jdbc:mysql://localhost:3306/study
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
在浏览器中输入localhost:8080,回车显示初始的index界面。到这里项目的初步搭建已经完成,下面实现一些简单的业务逻辑。
首先连接一下数据库(记得先打开MySQL服务)
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);
(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)
(4)Web层:就是Controller层,实现与web前端的交互。
创建目录结构:
各文件代码展示
在application配置文件中添加MyBatis配置
spring.datasource.name=study
spring.datasource.url=jdbc:mysql://localhost:3306/study
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.example.study.pojo
pom.xml文件配置信息
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>study</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>study</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!--thymeleaf模板引擎配置-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!--Web依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--MyBatis配置-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.2.0</version>
</dependency>
<!--MySQL数据库配置-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.25</version>
<scope>runtime</scope>
</dependency>
<!--单元测试配置-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.testng</groupId>
<artifactId>testng</artifactId>
<version>RELEASE</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Pojo类,依据数据库表生成set和get方法
package com.example.study.pojo;
public class UserPojo {
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;
}
}
DAO层访问数据库接口文件(<mapper>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.study.mapper.UserMapper">
<select id="getInfo" parameterType="String" resultType="com.example.study.pojo.UserPojo">
SELECT * FROM user WHERE name = #{name} AND password = #{password}
</select>
</mapper>
Service层业务接口类
package com.example.study.service;
import com.example.study.pojo.UserPojo;
public interface UserService {
UserPojo loginIn(String name, String password);
}
Service层业务实现类编写,注解@Service,注入DAO
package com.example.study.serviceImpl;
import com.example.study.pojo.UserPojo;
import com.example.study.mapper.UserMapper;
import com.example.study.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 UserPojo loginIn(String name, String password) {
return userMapper.getInfo(name,password);
}
}
项目启动类,添加注解@MapperScan项目启动时扫描mapper接口
package com.example.study;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.study.mapper")
public class StudyApplication {
public static void main(String[] args) {
SpringApplication.run(StudyApplication.class, args);
}
}
编写测试类
package com.example.study;
import org.junit.Test;
import com.example.study.pojo.UserPojo;
import com.example.study.service.UserService;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
@SpringBootTest
public class StudyApplicationTests {
@Autowired
UserService userService;
@Test
public void contextLoads() {
UserPojo userPojo = userService.loginIn("二","222");
System.out.print("该用户ID为:");
System.out.println(userPojo.getId());
}
}
Controller层,添加@controller注解,注入Service服务
package com.example.study.controller;
import com.example.study.pojo.UserPojo;
import com.example.study.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){
UserPojo userPojo = userService.loginIn(name,password);
if (userPojo != null){
return "success";
}else {
return "error";
}
}
}
html文件:
(1)login.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>登录</title>
</head>
<body>
<form role="form" action="/loginIn" method="post">
账号:<input type="text" id="name" name="name"> <br>
密码:<input type="password" id="passwword" name="password"> <br>
<input type="submit" id="login" value="login">
</form>
</body>
</html>
(2)success.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>登录成功</title>
</head>
<body>
<h1>登录成功!</h1>
</body>
</html>
(3)error.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>登录失败</title>
</head>
<body>
<h1>登录失败!</h1>
</body>
</html>
运行测试类
运行结果
但有一条WARN:
2021-06-30 08:49:12.767 WARN 1840 --- [ main] com.zaxxer.hikari.util.DriverDataSource : Registered driver with driverClassName=com.mysql.jdbc.Driver was not found, trying direct instantiation.
将 import org.junit.jupiter.api.Test; 修改为 import org.junit.Test; 即可
运行TestApplication.java文件,启动项目,在浏览器输入localhost:8080/login