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这篇文章给大家介绍Spring boot 中怎么配置mybatis,内容非常详细,感兴趣的小伙伴们可以参考借鉴,希望对大家能有所帮助。
1 添加相关maven文件
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.1.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional> </dependency> </dependencies>
完整的pom包这里就不贴了,大家直接看源码
2、application.properties 添加数据库和mybatis配置
mybatis.type-aliases-package=com.neo.entity //对应实体类的包名 spring.datasource.driverClassName = com.mysql.jdbc.Driver spring.datasource.url = jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf-8 spring.datasource.username = root spring.datasource.password = root
springboot会自动加载spring.datasource.*相关配置,数据源就会自动注入到sqlSessionFactory中,sqlSessionFactory会自动注入到Mapper中,对了你一切都不用管了,直接拿起来使用就行了。
在启动类中添加对mapper包扫描@MapperScan
@SpringBootApplication @MapperScan("com.neo.mapper") public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } }
或者直接在Mapper类上面添加注解@Mapper,建议使用上面那种,不然每个mapper加个注解也挺麻烦的
3、开发Mapper
第三步是最关键的一块,sql生产都在这里
public interface UserMapper { @Select("SELECT * FROM users") @Results({ @Result(property = "userSex", column = "user_sex", javaType = UserSexEnum.class), @Result(property = "nickName", column = "nick_name") }) List<UserEntity> getAll(); @Select("SELECT * FROM users WHERE id = #{id}") @Results({ @Result(property = "userSex", column = "user_sex", javaType = UserSexEnum.class), @Result(property = "nickName", column = "nick_name") }) UserEntity getOne(Long id); @Insert("INSERT INTO users(userName,passWord,user_sex) VALUES(#{userName}, #{passWord}, #{userSex})") void insert(UserEntity user); @Update("UPDATE users SET userName=#{userName},nick_name=#{nickName} WHERE id =#{id}") void update(UserEntity user); @Delete("DELETE FROM users WHERE id =#{id}") void delete(Long id); }
为了更接近生产我特地将user_sex、nick_name两个属性在数据库加了下划线和实体类属性名不一致,另外user_sex使用了枚举
@Select 是查询类的注解,所有的查询均使用这个
@Result 修饰返回的结果集,关联实体类属性和数据库字段一一对应,如果实体类属性和数据库属性名保持一致,就不需要这个属性来修饰。
@Insert 插入数据库使用,直接传入实体类会自动解析属性到对应的值
@Update 负责修改,也可以直接传入对象
@delete 负责删除
了解更多属性参考这里
注意,使用#符号和$符号的不同:
// This example creates a prepared statement, something like select * from teacher where name = ?; @Select("Select * from teacher where name = #{name}") Teacher selectTeachForGivenName(@Param("name") String name); // This example creates n inlined statement, something like select * from teacher where name = 'someName'; @Select("Select * from teacher where name = '${name}'") Teacher selectTeachForGivenName(@Param("name") String name);
4、使用
上面三步就基本完成了相关dao层开发,使用的时候当作普通的类注入进入就可以了
@RunWith(SpringRunner.class) @SpringBootTest public class UserMapperTest { @Autowired private UserMapper UserMapper; @Test public void testInsert() throws Exception { UserMapper.insert(new UserEntity("aa", "a123456", UserSexEnum.MAN)); UserMapper.insert(new UserEntity("bb", "b123456", UserSexEnum.WOMAN)); UserMapper.insert(new UserEntity("cc", "b123456", UserSexEnum.WOMAN)); Assert.assertEquals(3, UserMapper.getAll().size()); } @Test public void testQuery() throws Exception { List<UserEntity> users = UserMapper.getAll(); System.out.println(users.toString()); } @Test public void testUpdate() throws Exception { UserEntity user = UserMapper.getOne(3l); System.out.println(user.toString()); user.setNickName("neo"); UserMapper.update(user); Assert.assertTrue(("neo".equals(UserMapper.getOne(3l).getNickName()))); } }
源码中controler层有完整的增删改查,这里就不贴了
极简xml版本
极简xml版本保持映射文件的老传统,优化主要体现在不需要实现dao的是实现层,系统会自动根据方法名在映射文件中找对应的sql.1、application.yml 配置
spring: datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/用哪个数据库?useUnicode=true&characterEncoding=utf-8 username: 用户名 password: 密码 server: port: 8080 mybatis: config-location: classpath:config/mybatis-config.xml mapper-locations: classpath:mapper/*.xml MyBatis 配置项解读: config-location:指定 MyBatis 主配置文件的位置 mapper-locations:指定 mapper 文件的位置。如果在项目中你的 mapper 文件是按目录来放置,那么对应的配置就变成:mapper-locations: classpath:mapper/*/*.xml
这时候假设我们的 resources 结构是这样的:
|-resources |--config |---application.yml |---mybatis-config.xml |--mapper |---CityMapper.xml
3、mybatis-config.xml 配置
<?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> <typeAliases> <package name="com.mybatis.domain"/> </typeAliases> <!--<mappers>--> <!--<mapper resource="sample/mybatis/mapper/CityMapper.xml"/>--> <!--<mapper resource="sample/mybatis/mapper/HotelMapper.xml"/>--> <!--</mappers>--> </configuration>
这个配置见仁见智,在它里面我就配置了一个
typeAliases
。不了解的同学可以移步文档查看相关解释。
你也可以把 mapper 配置在此处,有多少个 mapper 就配置多少次,当然,我们已经在 application.yml中批量指定了,很方便,就不用在此处一个个写。
2、添加User的映射文件
<mapper namespace="com.neo.mapper.UserMapper" > <resultMap id="BaseResultMap" type="com.neo.entity.UserEntity" > <id column="id" property="id" jdbcType="BIGINT" /> <result column="userName" property="userName" jdbcType="VARCHAR" /> <result column="passWord" property="passWord" jdbcType="VARCHAR" /> <result column="user_sex" property="userSex" javaType="com.neo.enums.UserSexEnum"/> <result column="nick_name" property="nickName" jdbcType="VARCHAR" /> </resultMap> <sql id="Base_Column_List" > id, userName, passWord, user_sex, nick_name </sql> <select id="getAll" resultMap="BaseResultMap" > SELECT <include refid="Base_Column_List" /> FROM users </select> <select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" > SELECT <include refid="Base_Column_List" /> FROM users WHERE id = #{id} </select> <insert id="insert" parameterType="com.neo.entity.UserEntity" > INSERT INTO users (userName,passWord,user_sex) VALUES (#{userName}, #{passWord}, #{userSex}) </insert> <update id="update" parameterType="com.neo.entity.UserEntity" > UPDATE users SET <if test="userName != null">userName = #{userName},</if> <if test="passWord != null">passWord = #{passWord},</if> nick_name = #{nickName} WHERE id = #{id} </update> <delete id="delete" parameterType="java.lang.Long" > DELETE FROM users WHERE id =#{id} </delete> </mapper>
其实就是把上个版本中mapper的sql搬到了这里的xml中了
3、编写Dao层的代码
public interface UserMapper { List<UserEntity> getAll(); UserEntity getOne(Long id); void insert(UserEntity user); void update(UserEntity user); void delete(Long id); }
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