spring boot 整合mybatis

一：注解模式整合

spring boot默认以注解版与mybatis底层整合，MybatisAutoConfiguration中MybatisProperties种属性字段允许用户自定义配置。SqlSessionFactory对象也在配置类中自动注入；我们只需要编写dao层即可。

@Mapper
public interface DepartmentMapper {

    @Select("select * from department where id=#{id}")
    public Department getDeptById(Integer id);

    @Delete("delete from department where id=#{id}")
    public int deleteDeptById(Integer id);

    @Options(useGeneratedKeys = true,keyProperty = "id")
    @Insert("insert into department(department_name) values(#{departmentName})")
    public int insertDept(Department department);

    @Update("update department set department_name=#{departmentName} where id=#{id}")
    public int updateDept(Department department);
}

为了支持驼峰法命名，需要手动写一个配置类，重写ConfigurationCustomizer类中方法customize；

 

public class MyBatisConfig {

    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer(){

            @Override
            public void customize(Configuration configuration) {
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }
}

 

上面的@Mapper注解必须要有，否则需要在启动类中添加@MapperScan(value =“com.*”)

二：xml配置模式

首先application.yml中添加xml配置文件目录

mybatis:
  # 指定全局配置文件位置
  config-location: classpath:mybatis/mybatis-config.xml
  # 指定sql映射文件位置
  mapper-locations: classpath:mybatis/mapper/*.xml

添加相应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"/> <!--开启驼峰命名法 -- >
    </settings>
</configuration>

这样添加完成后，dao层只需要写相应的接口，不需要在写相应的注解sql；

数据源配置参考前文介绍：https://blog.csdn.net/Java_Jsp_Ssh/article/details/83119798