1、添加Dao层相关包,接口和实现类
DeptDao.java
package cn.itcast.scm.dao; import cn.itcast.scm.entity.Dept; public interface DeptDao { public Dept selectDept(Integer deptId); public int insertDept(Dept dept); }
DeptDaoImpl.java
package cn.itcast.scm.dao.impl; import javax.annotation.Resource; import org.mybatis.spring.SqlSessionTemplate; import org.springframework.stereotype.Repository; import cn.itcast.scm.dao.DeptDao; import cn.itcast.scm.entity.Dept; @Repository("deptDao") public class DeptDaoImpl implements DeptDao { @Resource private SqlSessionTemplate sqlSessionTemplate; /** * 根据部门编号查询部门信息 * * @param deptId 部门编号 * @return 部门信息 */ public Dept selectDept(Integer deptId) { Dept dept = sqlSessionTemplate.selectOne( "cn.itcast.scm.entity.DeptMapper.selectDept", deptId); return dept; } /** * 添加部门信息 * * @param dept 部门信息 * @return 添加成功的记录数 */ public int insertDept(Dept dept) { System.out.println("------dao.dept:" + dept); return sqlSessionTemplate.insert( "cn.itcast.scm.entity.DeptMapper.insertDept", dept); } }
2、添加业务层相关包,接口和实现类
2.1编写接口与实现类,实现类用@Service进行注解。
DeptService.java
package cn.itcast.scm.service; import cn.itcast.scm.entity.Dept; public interface DeptService { public Dept selectDept(Integer deptId); public int insertDept(Dept dept) throws Exception; }
DeptServiceImpl.java
package cn.itcast.scm.service.impl; import javax.annotation.Resource; import org.springframework.stereotype.Service; import cn.itcast.scm.dao.DeptDao; import cn.itcast.scm.entity.Dept; import cn.itcast.scm.service.DeptService; @Service public class DeptServiceImpl implements DeptService{ @Resource DeptDao deptDao; @Override public Dept selectDept(Integer deptId) { return deptDao.selectDept(deptId); } @Override public int insertDept(Dept dept) throws Exception{ return deptDao.insertDept(dept); } }
2.2修改各层调用
控制器类通过业务层接口调用业务层,业务层再通过dao接口
2.2.1 修改DeptAction.java 控制器
package cn.itcast.scm.action; import javax.annotation.Resource; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import cn.itcast.scm.entity.Dept; import cn.itcast.scm.service.DeptService; @Controller @RequestMapping(value = "/dept") public class DeptAction { @Resource private DeptService deptService; public DeptAction() { System.out.println("DeptAction初始化。。。"); } @RequestMapping(value = "/select") public void select(Integer deptId) { System.out.println(deptService.selectDept(deptId)); } @RequestMapping(value = "/insert") public String insert(Dept dept) { try { System.out.println("---action.dept:" + dept); deptService.insertDept(dept); } catch (Exception e) { e.printStackTrace(); } return "forward:/jsp/main.jsp"; } }
2.2.2 修改service层,DeptServiceImpl.java
package cn.itcast.scm.service.impl; import javax.annotation.Resource; import org.springframework.stereotype.Service; import cn.itcast.scm.dao.DeptDao; import cn.itcast.scm.entity.Dept; import cn.itcast.scm.service.DeptService; @Service public class DeptServiceImpl implements DeptService{ @Resource DeptDao deptDao; @Override public Dept selectDept(Integer deptId) { return deptDao.selectDept(deptId); } @Override public int insertDept(Dept dept) throws Exception{ int i =deptDao.insertDept(dept); /** * try catch的异常错误,如果applicationConte不配置rollback-for="Exception",这种情况不回滚 */ Class.forName("cn.itcast.aaaa");//需要try catch的异常错误(方法上抛出了异常,此处不try catch) return deptDao.insertDept(dept); } }
通过上面调整,即可正常测试代码了。下面配置好applicationContext.xml和spring-mvc.xml,来说明一个关于异常回滚的知识点。
3、修改applicationContext.xml与spring-mvc.xml文件
3.1 applicationContext.xml和spring-mvc.xml正确配置service和controller,可以测试异常回滚。例如在service层的异常,代码如下:
3.1.1 修改applicationContext.xml配置
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd"> <!-- 配置数据源,记得去掉myBatis-config.xml的数据源相关配置 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="com.mysql.jdbc.Driver" /> <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8" /> <property name="user" value="root" /> <property name="password" value="root" /> </bean> <!-- 配置session工厂 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:myBatis-config.xml" /> </bean> <!-- 配置SessionTemplate,已封装了繁琐的数据操作--> <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate"> <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/> </bean> <!-- 配置事务管理器,管理数据源事务处理--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource" /> </bean> <!-- 配置事务通知 --> <tx:advice id="advice" transaction-manager="transactionManager"> <tx:attributes> <!-- 默认只处理运行时异常,可加rollback-for="Exception/Throwable"等处理所有异常或包括错误 --> <tx:method name="insert*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="update*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="delete*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="*" propagation="SUPPORTS"/> </tx:attributes> </tx:advice> <!-- 配置切面织入的范围,把事务边界定在service层 --> <aop:config> <aop:advisor advice-ref="advice" pointcut="execution(* cn.itcast.scm.service.impl.*.*(..))"/> </aop:config> <!-- 自动扫描组件,要把controller去除,他们是在spring-mvc.xml中配置,如果不去除会影响事务管理。 -->
<context:component-scan base-package="cn.itcast"> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/> </context:component-scan>
</beans>
3.1.2 修改spring-mvc.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd "> <!-- 同时开启json格式的支持 (可省) --> <mvc:annotation-driven></mvc:annotation-driven> <!-- 扫描所有的controller 但是不扫描service -->
<context:component-scan base-package="cn.itcast"> <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/> </context:component-scan>
</beans>
3.2 知识点:applicationConte.xml中配置事务通知时,配置属性rollback-for,rollback-for="Exception/Throwable"可以处理所有异常或包括错误。
<!-- 配置事务通知 --> <tx:advice id="advice" transaction-manager="transactionManager"> <tx:attributes> <!-- 默认只处理运行时异常,可加rollback-for="Exception/Throwable"等处理所有异常或包括错误 --> <tx:method name="insert*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="update*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="delete*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="*" propagation="SUPPORTS"/> </tx:attributes> </tx:advice>
3.2.1如果不配置rollback-for="Exception",默认只会回滚运行时异常,例如上面在service层代码中:
public int insertDept(Dept dept) throws Exception{ int i =deptDao.insertDept(dept); /** * 运行时异常,applicationContext.xml中不配置rollback-for="Exception",默认可正常回滚 */ Integer.parseInt("aa"); return deptDao.insertDept(dept); }
3.2.2 去掉applicationContext.xml中rollback-for="Exception",对于错误不会回滚,如下配置和service层代码
<!-- 配置事务通知 --> <tx:advice id="advice" transaction-manager="transactionManager"> <tx:attributes> <!-- 默认只处理运行时异常,可加rollback-for="Exception/Throwable"等处理所有异常或包括错误 --> <tx:method name="insert*" propagation="REQUIRED" /> <tx:method name="update*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="delete*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="*" propagation="SUPPORTS"/> </tx:attributes> </tx:advice>
代码DeptServiceImpl.java
public int insertDept(Dept dept) throws Exception{ int i =deptDao.insertDept(dept); /** * try catch的异常错误,如果applicationContext.xml不配置rollback-for="Exception",这种情况不回滚 */ Class.forName("cn.itcast.aaaa");//需要try catch的异常错误(方法上抛出了异常,此处不try catch) return deptDao.insertDept(dept); }
因此,一般都在applicationContext.xml配置rollback-for="Exception",处理所有异常。
4.在service层@Autowired(按类型搜索)方式注入dao接口,spring将其转换成bean注入,
并将Entity的映射文件Mapper.xml文件移至dao的包下,并修改文件中的namespace为dao接口的全限定名。
在调整applicationContext.xml,配置转换器。具体操作如下:
4.1 删除dao接口的实现类,删除如下图:
4.2 测试类也删除(TestDeptDao.java),因为没有了dao接口的实现类,这里测试代码无法调用DeptDaoImpl了。
4.3 调整dao接口和Entity的映射文件Mapper.xml中的包名为dao接口的全限定名(cn.itcast.scm.dao.DeptDao)
4.3.1 service层使用@Autowired自动装配dao接口,将被spring自动转换成bean;
package cn.itcast.scm.service.impl; import javax.annotation.Resource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import cn.itcast.scm.dao.DeptDao; import cn.itcast.scm.entity.Dept; import cn.itcast.scm.service.DeptService; @Service public class DeptServiceImpl implements DeptService{ /** * 原来@Resource spring通过名称搜索,在此处仍用@Resource的划,spring先通过名称匹配, * 如果未找到再根据类型搜索 * 此处,规范使用@Autowired,spring直接根据类型匹配(因为dao已经没有实现类了),提高效率; * spring会自动为其生成一个代理 */ @Autowired DeptDao deptDao; @Override public Dept selectDept(Integer deptId) { return deptDao.selectDept(deptId); } @Override public int insertDept(Dept dept) throws Exception{ int i =deptDao.insertDept(dept); /** * try catch的异常错误,如果applicationConte不配置rollback-for="Exception",这种情况不回滚 */ Class.forName("cn.itcast.aaaa");//需要try catch的异常错误(方法上抛出了异常,此处不try catch) return deptDao.insertDept(dept); } }
4.3.2 移动实体Entity的映射文件Mapper.xml到dao包下,并修改文件内的包名(<mapper namespace="cn.itcast.scm.dao.DeptDao">)
<?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="cn.itcast.scm.dao.DeptDao"> <resultMap type="Dept" id="deptResultMap"> <id property="deptId" column="dept_id" /> <result property="deptName" column="dept_name" /> <result property="deptAddress" column="dept_address" /> </resultMap> <!-- id和命名空间用来定位SQL语句,parameterType表示参数的类型,resultMap返回类型 --> <select id="selectDept" parameterType="Integer" resultMap="deptResultMap"> <!--参数的写法#{deptID} --> select dept_id,dept_name,dept_address from dept where dept_id=#{deptID} </select> <insert id="insertDept" parameterType="Dept"> insert into dept(dept_name,dept_address) values(#{deptName},#{deptAddress}); </insert> </mapper>
4.3.3 同时删除myBatis-config.xml中对Mapper的配置
<?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> <!-- 通过别名简化对类的使用 --> <typeAliases> <!-- 通过package, 可以直接指定package的名字, mybatis会自动扫描你指定包下面的javabean, 并且默认设置一个别名,默认的名字为非限定类名来作为它的别名。 --> <package name="cn.itcast.scm.entity"/> </typeAliases> </configuration>
4.4 在applicationContext.xml配置转换器
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd"> <!-- 配置数据源,记得去掉myBatis-config.xml的数据源相关配置 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="com.mysql.jdbc.Driver" /> <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8" /> <property name="user" value="root" /> <property name="password" value="root" /> </bean> <!-- 配置session工厂 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:myBatis-config.xml" /> <!--配置扫描式加载SQL映射文件,记得去掉mybatis-config配置-->
<property name="mapperLocations" value="classpath:cn/itcast/scm/dao/*.xml"/>
</bean> <!-- 配置事务管理器,管理数据源事务处理--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource" /> </bean> <!-- 配置事务通知 --> <tx:advice id="advice" transaction-manager="transactionManager"> <tx:attributes> <!-- 默认只处理运行时异常,可加rollback-for="Exception/Throwable"等处理所有异常或包括错误 --> <tx:method name="insert*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="update*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="delete*" propagation="REQUIRED" rollback-for="Exception"/> <tx:method name="*" propagation="SUPPORTS"/> </tx:attributes> </tx:advice> <!-- 配置切面织入的范围,把事务边界定在service层 --> <aop:config> <aop:advisor advice-ref="advice" pointcut="execution(* cn.itcast.scm.service.impl.*.*(..))"/> </aop:config> <!-- 自动扫描组件,要把controller去除,他们是在spring-mvc.xml中配置,如果不去除会影响事务管理。 --> <context:component-scan base-package="cn.itcast"> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/> </context:component-scan> <!-- 配置SessionTemplate,已封装了繁琐的数据操作--> <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate"> <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/> </bean> <!-- 配置 转换器,对于在basePackage设置的包(包括子包)下的接口类, 如果在Mapper.xml文件中定义过,将被转换成spring的BEAN,生成代理 在调用 的地方通过@Autowired方式将可以注入接口实例 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="sqlSessionFactory" ref="sqlSessionFactory"/> <property name="basePackage" value="cn.itcast.scm.dao"/> </bean>
</beans>
5.运行程序,在index.jsp,提交表单进行数据插入的测试。
项目结构截图: