springboot 整合MyBatis

步骤

1. 搭建SpringBoot工程。
2. 引入MyBatis起步依赖，添加PostgreSQL驱动。
3. 编写DataSource和MyBatis相关配置。
4. 定义表和实体类。
5. 编写dao和mapper文件/纯注解开发。
6. 测试

搭建SpringBoot
此处选择jdbc、PostgreSQL Driver、Mybatis

起步依赖

      org.mybatis.spring.boot
      mybatis-spring-boot-starter
      2.2.0



      org.postgresql
      postgresql
      runtime

DataSource和MyBatis相关配置
Application.yml文件

#datasource
spring:
  datasource:
    url: jdbc:postgresql://192.168.0.103:5432/yytest
    username: postgres
    password: 123456@
    driver-class-name: org.postgresql.Driver

定义表和实体类
postgresql安装略。

User.java

package com.yy.springboot_mybatis.domain;

public class User {
    private int id;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

    public void setId(int 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;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + ''' +
                ", password='" + password + ''' +
                '}';
    }
}

纯注解
UserMapper.java

package com.yy.springboot_mybatis.mapper;

import com.yy.springboot_mybatis.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface UserMapper {

    @Select("select * from t_user")
    public List findAll();
}

测试类

package com.yy.springboot_mybatis;

import com.yy.springboot_mybatis.domain.User;
import com.yy.springboot_mybatis.mapper.UserMapper;
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 SpringbootMybatisApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void test() {
        List list = userMapper.findAll();
        System.out.println(list);
    }

}

整体目录结构

测试

xml开发方式
相比于注解开发要多写一个xml文件，且mapper中不直接编写sql
编写UserXmlMapper.java文件

package com.yy.springboot_mybatis.mapper;

import com.yy.springboot_mybatis.domain.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface UserXmlMapper {

    public List findAll2();
}

编写UserMapper.xml文件

    
        select * from t_user
    

测试类

package com.yy.springboot_mybatis;

import com.yy.springboot_mybatis.domain.User;
import com.yy.springboot_mybatis.mapper.UserMapper;
import com.yy.springboot_mybatis.mapper.UserXmlMapper;
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 SpringbootMybatisApplicationTests {
    

    @Autowired
    private UserXmlMapper userXmlMapper;


    @Test
    public void test2() {
        List list = userXmlMapper.findAll2();
        System.out.println(list);
    }

}