好久没有写代码了，SpringBoot配置

SpringBoot快速开始

1.idea创建项目

1.首先是idea中快速创建springboot项目 2.选择开发框架 我选择了3.2，选择mybatis-framework和mysql-driver

2.创建相关数据表

1.创建一个user表（之前已经创建，此处就不更改了）

2.配置相应的实体类

package com.example.demo.pojo;

public class user {
    private Integer id;
    private String username;
    private String password;
    private String name;
    private Integer age;

    public user() {
    }

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

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

3.配置Mybatis 在application.properties中配置数据库连接

spring.application.name=demo

#数据库访问的url
spring.datasource.url=jdbc:mysql://localhost:3306/test
#数据库驱动类类名
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
#访问数据库-用户名
spring.datasource.username=root
#访问数据库-密码
spring.datasource.password=root
#mybatis的配置
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

4.配置Mapper

package com.example.demo.mapper;

import com.example.demo.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
@Mapper
public interface UserMapper {

    @Select("SELECT * FROM test.user")
    public List<User> findAll();
}

5.编写测试类

package com.example.demo;

import com.example.demo.Mapper.UserMapper;
import com.example.demo.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class DemoApplicationTests {

    @Test
    void contextLoads() {
    }
    @Autowired
    private UserMapper userMapper;

    @Test
    public void testUserMapper(){
       List<User> list = userMapper.findAll();
       for (User user:list){
          System.out.println(user);
       }
    }

}