SpringBoot整合MyBatis的三种方式

向右看齐 2021-09-23 12:14 474阅读 0赞

写一篇关于SpringBoot整合MyBatis的笔记，这里我写出三种整合的方式，分别为：注解版，xml版，配置类版。在此之前我对整合的实现做出一定简述：仓库管理使用的是Maven，SpringBoot默认集成了JDBC，当然我们可以使用更强大的Druid做为我们的数据源。无论哪种整合方式都需要添加myBatis的相关依赖：

<dependency>
    			<groupId>org.mybatis.spring.boot</groupId>
    			<artifactId>mybatis-spring-boot-starter</artifactId>
    			<version>1.3.2</version>
    		</dependency>

并且我使用的是MySql数据库:

<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    		</dependency>

**一、注解版**  
properties.yml数据库链接配置

server:
      port: 8066
    
    spring:
      datasource:
        driverClassName: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/yjkf_iot?seUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
        username: root
        password: ******

数据库实体类：

package com.yjkf.zh.admin.model;
    
    public class SysUser {
    
    	private long id;
        private String userName;
        private String  password;
        private String nickName;
        private Long status;
        private String mobile;
        private Long deptId;
        private String salt;
    	//省略get/set
    }

mapper接口

import com.yjkf.zh.test.model.SysUser;
    import org.apache.ibatis.annotations.Mapper;
    import org.apache.ibatis.annotations.Select;
    
    @Mapper
    public interface UserMapper {
    
        @Select("select * from sys_user where id=#{id}")
        public SysUser getUserId(long id);
    }

collector控制视图：

import com.yjkf.zh.test.mapper.UserMapper;
    import com.yjkf.zh.test.model.SysUser;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class UserController {
    
        @Autowired
        private UserMapper userMapper;
    
        @GetMapping("/user/{id}")
        public SysUser getUser(@PathVariable("id") long id){
            return userMapper.getUserId(id);
        }
    }

访问接口，以JSON的形式返回数据，特别注意，每个实体类都配置了@mapper，也可以在启动类上添加

@MapperScan(value="com.***.mapper")		//批量扫描所有mapper接口

，有些情况存在驼峰命名的影响，会获取不到值，在这里可以单独配置一个驼峰命名的配置类：

@Configuration
    	public class MyBatisConfig{
    	@Bean
    	public ConfigurationCustomizer configurationCustion(){
    		return new ConfigurationCustomizer(){
    			public void customize(Configuration configuration){
    				configuration.setMapUnderscoreToCamelCase(true);
    			}
    		}
    	}
    }

**二、配置文件**

resources下新建mybatis文件夹，并添加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>
       <settings>
       
            <setting name="mapUnderscoreToCamelCase" value="true"/>	
        </settings>
    </configuration>

并在mybatis下新建文件夹mapper,创建UserMapper.xml映射文件：

<?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.yjkf.zh.test.mapper.UserMapper">
        <select id="getUserId" resultType="com.yjkf.zh.test.model.SysUser">
        select * from sys_user where id = #{id}
      </select>
    </mapper>

对应的mapper接口为：

@Mapper
    public interface UserMapper {
    
        //@Select("select * from sys_user where id=#{id}")
        public SysUser getUserId(long id);
    }

properties.yml文件添加：

mybatis:
      config-location: classpath:mybatis/mybatis-config.xml
      mapper-locations: classpath:mybatis/mapper/*.xml

controller控制类没有变动。

**三、类配置方式**

import org.apache.ibatis.session.SqlSessionFactory;
    import org.mybatis.spring.SqlSessionFactoryBean;
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
    
    
    import javax.sql.DataSource;
    
    @Configuration
    @MapperScan("com.yjkf.zh.**.dao")
    public class MybatisConfig {
    
        @Autowired
        private DataSource dataSource;
    
        @Bean
        public SqlSessionFactory sqlSessionFactory() throws Exception{
            SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
            sessionFactoryBean.setDataSource(dataSource);
            sessionFactoryBean.setTypeAliasesPackage("com.zhkf.zh.**.model");   //扫描model
            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            sessionFactoryBean.setMapperLocations(resolver.getResources("classpath*:**/sqlmap/*.xml"));     //扫描映射文件
            return sessionFactoryBean.getObject();
        }
    }

这里内部执行原理太多，不便于介绍，适用于初学者体验以及大家复习参考。