SpringBoot整合Mybatis
springBoot整合Mybatis
1.导入依赖
<dependencies> <!-- web支持，SpringMVC， Servlet支持等 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- thymeleaf --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.0</version> </dependency> <!-- Spring Security --> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-web</artifactId> <version>4.2.3.RELEASE</version> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-config</artifactId> <version>4.2.3.RELEASE</version> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-taglibs</artifactId> <version>4.2.3.RELEASE</version> </dependency> <!-- jstl for jsp page --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>${jstl.version}</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.7</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.41</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <scope>test</scope> </dependency> <!--activceMq--> <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-core</artifactId> <version>5.5.1</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jms</artifactId> <version>3.2.4.RELEASE</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.8</version> </dependency> </dependencies> <properties> <java.version>1.8</java.version> <!-- 修改thymeleaf的版本 --> <thymeleaf.version>3.0.2.RELEASE</thymeleaf.version> <thymeleaf-layout-dialect.version>2.0.4</thymeleaf-layout-dialect.version> </properties> <!--<build>--> <!--<resources>--> <!--<resource>--> <!--<directory>src/main/java</directory>--> <!--<includes>--> <!--<include>**/*.xml</include>--> <!--<include>**/*.properties</include>--> <!--</includes>--> <!--<filtering>true</filtering>--> <!--</resource>--> <!--<resource>--> <!--<directory>src/main/resources</directory>--> <!--<includes>--> <!--<include>**/*.xml</include>--> <!--<include>**/*.properties</include>--> <!--</includes>--> <!--<filtering>true</filtering>--> <!--</resource>--> <!--</resources>--> <!--</build>-->
2.建立dao层
1.编写mybatis总配置文件（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="cacheEnabled" value="true" /> <!-- 全局映射器启用缓存 --> <setting name="useGeneratedKeys" value="true" /> <!-- 允许 JDBC 支持自动生成主键 --> <setting name="defaultExecutorType" value="REUSE" /> <!-- 配置默认的执行器 --> <setting name="logImpl" value="SLF4J" /> <!-- 指定 MyBatis 所用日志的具体实现 --> <!-- <setting name="mapUnderscoreToCamelCase" value="true"/> 驼峰式命名 --> </settings> </configuration>
3.编写实体类和Mapper接口和mapper配置文件
1.实体类实现 Serializable接口
2.mapper接口和mapper配置文件满足mybatis框架的要求
3.编写application总配置文件
spring: thymeleaf: cache: false datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/security?characterEncoding=utf-8&useSSL=false username: root password: mybatis: # 搜索指定包别名 typeAliasesPackage: # 配置mapper的扫描，找到所有的mapper.xml映射文件 mapperLocations: classpath*:mybatis/mapper/*.xml # 加载全局的配置文件 configLocation: classpath:mybatis/mybatis-config.xml
4.springBoot的注解
1.@SpringBootApplication
包括：@Configuration,@EnableAutoConfiguration,@ComponentScan
（1）@Configuration：提到@Configuration就要提到他的搭档@Bean。使用这两个注解就可以创建一个简单的spring配置类，可以用来替代相应的xml配置文件。
@Configuration public class Conf { @Bean public Car car() { Car car = new Car(); car.setWheel(wheel()); return car; } @Bean public Wheel wheel() { return new Wheel(); } }
（2）@EnableAutoConfiguration：能够自动配置spring的上下文，试图猜测和配置你想要的bean类，通常会自动根据你的类路径和你的bean定义自动配置。
（3）@ComponentScan：会自动扫描指定包下的全部标有@Component的类，并注册成bean，当然包括@Component下的子注解@Service,@Repository,@Controller。
@RestController
注解那么返回的结果会自动解析为json格式的字段，如果加@Controller注解，那么图中"return json;"便会解析为json.html，并去寻找该页面，而不是返回json中的内容。
@EnableTransactionManagement为加事务管理。
@Mapper注解
作用：在接口类上添加了@Mapper，在编译之后会生成相应的接口实现类添加位置：接口类上面
@MapperScan（）
作用：指定要变成实现类的接口所在的包，然后包下面的所有接口在编译之后都会生成相应的实现类添加位置：是在Springboot启动类上面添加。
@Select({"select id,user_name,user_password,user_email,user_info,head_img,create_time from sys_user where id = #{id}"}) @Results(id="userMap", value={ @Result(column="id", property="id", id=true), @Result(column="user_name", property="userName"), @Result(column="user_password ", property="userPassword"), @Result(column="user_email", property="userEmail"), @Result(column="user_info", property="userInfo"), @Result(column="head_img", property="headImg", jdbcType=JdbcType.BLOB), @Result(column="create_time", property="createTime", jdbcType=JdbcType.TIMESTAMP) }) SysUser selectUserByUserId(Long id); @Select({"select * from sys_user"}) @ResultMap("userMap") List<SysUser> selectUsers();
@Results注解表示属性信息为一个resultMap，id则是命名空间内识别该resultMap的唯一标识，
column和property及其其他属性与在resultMap标签内定义方式相同。 此处的定义，@Results注解必须与@Select查询同方法在一起，不可以单独定义@Results注解，
会不被识别的。定义后，在其他方法处，便可以使用该@Results定义的resultMap了。
一对一注解 @One（）
public interface PersonMapper {
@Select("select * from tb_person where id= #{id}")
@Results({
@Result(id=true,column = "id",property = "id"),
@Result(column = "name",property = "name"),
@Result(column = "age",property = "age"),
@Result(column = "sex",property = "sex"),
@Result(column = "card_id",property = "card",one = @One(select = "org.arunner.mapper.CardMapper.selectCardById",fetchType = FetchType.EAGER)),
})
Person selectPersonById(Integer id);
}
fetchType ：延迟加载类型
@One（）：一对一注解
一对多注解many = @Many（）
public interface ClazzMapper { @Select("select * from tb_clazz where id= #{id}") @Results({ @Result(id = true,column = "id",property = "id"), @Result(column = "name",property = "name"), @Result(column = "code",property = "code"), //@many注解的select属性表示需要关联执行的SQL语句 //FetchType.LAZY表示查询的类型是延迟加载 @Result(column = "id",property = "students",many = @Many(select = "org.fkit.mapper.StudentMapper.selectByClazzId",fetchType = FetchType.LAZY)), }) //根据ID查询班级信息 Clazz selectById(Integer id);
}
多对多查询many=@many（）
public interface IUserDao { //根据id得到用户： @Select("select * from users where uid = #{uid}") @Results({ @Result(id=true,column="uid",property="uid"), @Result(column="uname",property="uname"), @Result(column="uid",property="roles", many=@Many( select="com.desert.dao.IRolesDao.getAllRolesByuid", fetchType= FetchType.LAZY ) ) }) public Users getUsersById(int uid); } public interface IRolesDao { //根据用户id得到所有的角色： @Select("select * from roles where rid in(select rid from u_r where uid=1)") public List<Roles> getAllRolesByuid(int uid); }
