SpringBoot整合MyBatis 和 MyBatis-Plus-蒲公英云

Java知识点总结：想看的可以从这里进入

2.10、整合MyBatis

导入MyBatis的启动器

<!--mybatis的启动器-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.0</version>
</dependency>

yml文件中配置Mybatis属性（可以导入mybatis的XML配置文件）

<?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>
    <!--setting设置-->
    <settings>
        <!--日志STDOUT_LOGGING和LOG4J-->
        <setting name="logImpl" value="LOG4J"/>
    </settings>
    <!--设置别名 -->
    <typeAliases>
        <package name="com.yu.springbootproject.pojo"/>
    </typeAliases>
</configuration>
# mybatis的配置
mybatis:
  config-location: classpath:mybatis/mybatis.xml  #mybatis配置文件的位置
  mapper-locations: classpath:mapping/*.xml   #mapper的映射文件xml的位置，如果配置文件中配置了mappers，这里就不能配置了，会产生冲突
  #type-aliases-package: ***.mapper   扫描mapper接口,可以在启动类指定
  #configuration:
    #map-underscore-to-camel-case: true       默认开启驼峰命名法和 config-location 有冲突，只能写一个

启动类添加包的扫描

@SpringBootApplication
@MapperScan("xxxx.项目名.mapper")
public class SpringbootprojectApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringbootprojectApplication.class, args);
    }
}

添加log4j的日志

<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>
#将等级为DEBUG的日志信息输出到console和file这两个目的地，console和file的定义在下面的代码
log4j.rootLogger=DEBUG,console,file
#控制台输出的相关设置
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.Target=System.out
log4j.appender.console.Threshold=DEBUG
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d{yyyy-MM-dd HHss} [%t] [%c] [%p] -%m%n
#文件输出的相关设置
#log4j.appender.file = org.apache.log4j.RollingFileAppender
#log4j.appender.file.File=
#log4j.appender.file.MaxFileSize=10mb
#log4j.appender.file.Threshold=DEBUG
#log4j.appender.file.layout=org.apache.log4j.PatternLayout
#log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HHss} [%t] [%c] [%p] -%m%n
#日志输出级别
log4j.logger.org.mybatis=DEBUG
log4j.logger.java.sql=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.ResultSet=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

接口的扫描

在mapper接口中添加注解 @Mapper

@Mapper
public interface UserMapper {
    User selectByPrimaryKey(Integer userId);
}

映射xml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.yu.springbootproject.mapper.UserMapper">
  <resultMap id="BaseResultMap" type="com.yu.springbootproject.pojo.User">
    <id column="user_id" jdbcType="INTEGER" property="userId" />
    <result column="username" jdbcType="VARCHAR" property="username" />
    <result column="password" jdbcType="VARCHAR" property="password" />
    <result column="deleted" jdbcType="BIT" property="deleted" />
  </resultMap>
  <sql id="Base_Column_List">
    user_id, username, `password`, deleted
  </sql>
  <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
    select 
    <include refid="Base_Column_List" />
    from `user`
    where user_id = #{userId,jdbcType=INTEGER}
  </select>
</mapper>

编写Service，然后进行测试

public interface UserService {
     User selectByPrimaryKey(Integer userId);
}
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public User selectByPrimaryKey(Integer userId) {
        return userMapper.selectByPrimaryKey(userId);
    }
}
@Resource
private UserService userService;
@Test
public void userMapperTest(){
    User user = userService.selectByPrimaryKey(1);
    System.out.println(user.toString());
}

2.11、MyBatis-Plus

MyBatis-Plus 是基于Mybatis的一个工具，它是对MyBatis的增强，在其基础上只进行增强，不进行改变，是为了简化MyBatis开发，提高效率而研发的。

整合MyBatis-Plus 需要将MyBatis 的相关依赖移除。

导入MyBatis-Plus的启动器（移除原来mybatis的）

<!--mybatis-plus -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.2</version>
</dependency>

yml文件中配置mybatis-plus

# mybatis-plus的配置
mybatis-plus:
  type-aliases-package: com.yu.springboot.entity  #实体类路径
  mapper-locations: classpath:mapping/*.xml    # mappee接口映射的xml文件路径
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  #开启sql打印日志
    map-underscore-to-camel-case: true #将带有下划线的表字段映射为驼峰格式的实体类属性

启动类添加包的扫描（不变）

接口的扫描

在mapper接口继承 BaseMapper<>

public interface UserinfoMapper extends BaseMapper<Userinfo> {
}

映射xml文件

<mapper namespace="com.yu.springboot2test.mapper.UserinfoMapper">
  <resultMap id="BaseResultMap" type="com.yu.springboot2test.entity.Userinfo">
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="username" jdbcType="VARCHAR" property="username" />
    <result column="password" jdbcType="VARCHAR" property="password" />
    <result column="age" jdbcType="INTEGER" property="age" />
    <result column="is_deleted" jdbcType="BIT" property="isDeleted" />
    <result column="gmt_create" jdbcType="TIMESTAMP" property="gmtCreate" />
    <result column="gmt_modified" jdbcType="TIMESTAMP" property="gmtModified" />
  </resultMap>
  <sql id="Base_Column_List">
    id, username, `password`, age, is_deleted, gmt_create, gmt_modified
  </sql>
</mapper>

编写Service，然后进行测试

service接口继承IService，实现类继承ServiceImpl

public interface UserinfoService extends IService<Userinfo> {
}
@Service
public class UserinfoServiceImpl extends ServiceImpl<UserinfoMapper, Userinfo> implements UserinfoService {
}
@Resource
private UserinfoMapper userinfoMapper;
@Test
public void test2(){
    Userinfo userinfo = userinfoMapper.selectById(1L);
    System.out.println(userinfo);
}