mybatis与数据库的两种交互方式

这篇文章直接上核心代码：service层和controller层基本一样，不需要改变什么，只是dao层和xml配置文件关于和数据库交互这块有些许不同。。

1.使用传统的MyBatis提供的API。

spring----xml文件：

<!-- sqlSessinFactory --><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><!-- 加载mybatis的配置文件 --><property name="configLocation" value="classpath:mybatis-config.xml"><!-- 数据源 --><property name="dataSource" ref="dataSource"></property></property></bean><!-- SqlSessionTemplate持久化模板,在basedao里边不需要再继承SqlSessionDaoSupport --><bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate" scope="prototype"><constructor-arg index="0" ref="sqlSessionFactory"></constructor-arg></bean>

mybatis---xml文件（两个）：

<?xml version="1.0" encoding="UTF-8"?><configuration><typealiases> <!-- 用户 --><typealias alias="Teacher" type="com.yuan.entity.Teacher"></typealias><typealias alias="TeacherQuery" type="com.yuan.entity.query.TeacherQuery"></typealias></typealiases><mappers> <!-- 用户 --> <mapper resource="mybatis/mybatis-teacher.xml"></mapper></mappers></configuration>

这个要注意namespace：

<?xml version="1.0" encoding="UTF-8"?> <mapper namespace="teacher"><!-- 用于select查询公用抽取的列 --><sql id="Base_Column_List">ID,NAME,AGE,FILEURL,FILENAME</sql><select id="queryAll" resulttype="Teacher">SELECT <include refid="Base_Column_List">FROM TEACHER</include></select></mapper>

dao层的实现代码：BaseDaoImpl

package com.yuan.base;import java.lang.reflect.ParameterizedType;import java.util.List;import javax.annotation.Resource;import org.apache.ibatis.session.SqlSession;public class BaseDaoImpl<t> {@Resource(name="sqlSession")private SqlSession sqlSession;public SqlSession getSqlSession(){return sqlSession;}/** * * 获取传过来的泛型类名字 * @return */@SuppressWarnings({ "unchecked", "rawtypes" })public String getClassName(){//在父类中得到子类声明的父类的泛型信息 ParameterizedType pt = (ParameterizedType) this.getClass().getGenericSuperclass();Class<t> clazz = (Class) pt.getActualTypeArguments()[0];//clazz.getSimpleName().toString().toLowerCase(); 这里是获取实体类的简单名称，再把类名转为小写return clazz.getSimpleName().toString().toLowerCase();}public List<t> queryAll() {return sqlSession.selectList(this.getClassName()+".queryAll");}public int delete(String id) {return sqlSession.delete(this.getClassName()+".delete", id);}public int update(T t) {return sqlSession.update(this.getClassName()+".update", t);}public T getInfoById(String id) {return sqlSession.selectOne(this.getClassName()+".getInfoById", id);}public int add(T t) {return sqlSession.insert(this.getClassName()+".insert", t);}}</t></t></t>

teacherDaoImpl:

@Repositorypublic class TeacherDaoImpl extends BaseDaoImpl<teacher> implements TeacherDao{@Overridepublic List<teacher> getTeachetList(TeacherQuery teacherQuery) {return getSqlSession().selectList("teacher.getTeacherList", teacherQuery);}@Overridepublic Integer getCountByQuery(TeacherQuery teacherQuery) {return getSqlSession().selectOne("teacher.getCountByQuery", teacherQuery);}</teacher></teacher>

2.使用Mapper接口

spring----xml文件：

<!-- spring和MyBatis完美整合，不需要mybatis的配置映射文件 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"> <!-- 配置mybatis全局配置文件 --> <property name="configLocation" value="classpath:mybatis-config.xml"></property> <!-- 自动扫描mapping.xml文件 --> <property name="mapperLocations" value="classpath*:mybatis-mapping/*.xml"></property> </property></bean> <!-- DAO接口所在包名，Spring会自动查找其下的类 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.fx.anniversary.core.**.dao"> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property> </property></bean>

mybatis---xml文件（两个）：

mybatis-config.xml（mybatis的一些特性）：

<?xml version="1.0" encoding="UTF-8"?><configuration> <!-- 控制台打印查询语句 --> <settings><setting name="logImpl" value="STDOUT_LOGGING"></setting></settings> </configuration>

sql关联的xml（注意namespace的区别）:

<?xml version="1.0" encoding="UTF-8" ?><mapper namespace="com.fx.anniversary.core.dao.RedPacketDao"><select id="getIngotNum" resulttype="int" parametertype="String">selectingot_num from t_red_packet where id=#{id};</select></mapper>

dao层接口：

public interface RedPacketDao extends CommonDao<tredpacket>/** * 根据id得到中奖金币数量 * @param id * @return */public int getIngotNum(String id);}</tredpacket>

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dao层在service层的调用是一样的 都是通过@resource注解，注入成功。在测试代码里边，测试也是一样：

/** * 两种测试方法 * 类上边的两个注解都是需要的, 缺一不可 * @author yhl * */@RunWith(org.springframework.test.context.junit4.SpringJUnit4ClassRunner.class)@ContextConfiguration(locations="classpath:spring-yuan-service.xml")public class SpringTest {@Resourcepublic TeacherService teacherService;@Resourcepublic SpringAspect springAspect;@Testpublic void test1(){System.out.println(teacherService.queryAll());}@Testpublic void test2(){springAspect.selectTea("1");}}

或者：

public class TeacherServiceTest {@Testpublic void testTeacher(){ @SuppressWarnings("resource")ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-yuan-service.xml"); TeacherServiceImpl bean = (TeacherServiceImpl)ctx.getBean("teacherService"); System.out.println(bean.queryAll());}}