SpringBoot整合MyBatis 和 MyBatis-Plus

待我称王封你为后i 2024-03-25 23:19 87阅读 0赞

> [Java知识点总结：想看的可以从这里进入][Java]

#### 目录 ####

*   *   *  2.10、整合MyBatis
         *  2.11、MyBatis-Plus

#### 2.10、整合MyBatis ####

1.  导入MyBatis的启动器
    
        
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>
2.  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>
            
            <settings>
                
                <setting name="logImpl" value="LOG4J"/>
            </settings>
            
            <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
3.  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);
            }
        }
4.  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 HH:mm:ss} [%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 HH:mm:ss} [%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
5.  接口的扫描
    
    1.  在mapper接口中添加注解 @Mapper
        
            @Mapper
            public interface UserMapper {
                    
                User selectByPrimaryKey(Integer userId);
            }
    2.  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>
    3.  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());
            }
    
    ![image-20220923152906081][]

#### 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。

1.  导入MyBatis-Plus的启动器（移除原来mybatis的）
    
        
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.2</version>
        </dependency>
2.  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
3.  启动类添加包的扫描（不变）
4.  接口的扫描
    
    1.  在mapper接口继承 BaseMapper<>
        
            public interface UserinfoMapper extends BaseMapper<Userinfo> {
                    
            }
    2.  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>
    3.  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);
            }
        
        ![image-20230308174349798][]

[Java]: https://blog.csdn.net/yuandfeng/article/details/114333525
[image-20220923152906081]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/490d044e0ec9442b80d540c6f860de72.png
[image-20230308174349798]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/ac4eef0392844450887297188f8f9977.png