一、首先项目中使用的是Mybatis3.2.2 + Spring3.2.2,同时使用了mybatis-spring-1.2.0.jar来做Mybatis与Spring的整合。
二、使用了Mybatis推荐的mapper加载方式:
<!-- mybatis配置 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="writeDataSource" /> <property name="mapperLocations" value="classpath*:com/baofoo/admin/dao/**/impl/*Mapper.xml" /> </bean> <!-- mybatis自动扫描包下的mapper --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.baofoo.admin.dao" /> <!-- <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" /> --> </bean>
值得需要注意的是,在配置MapperScannerConfigurer时,这里并没有指定sqlSessionFactoryName以及sqlTemplateName。在没有指定的情况下,spring就会指定默认的查找规则进行查询,如分别查找到默认的sqlSessionFactory实现和sqlSessionTemplate实现,并注入到MapperFactoryBean中。
这种配置方式,在一个数据源时,没有问题,但是在如果存在多个数据源时,上面的配置就存在问题了。在多个数据源时,如果配置不正确,或者配置的步骤不正确,将直接产生莫名奇妙的问题
最初从tomcat启动一切正常,然后后面突然启动服务时报出如下异常:
java.lang.NoClassDefFoundError: Could not initialize class org.springframework.beans.factory.BeanCreationException at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:532) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:461) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:651) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:599) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:665) at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:518) at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:459) at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136) at javax.servlet.GenericServlet.init(GenericServlet.java:160) at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1274) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1186) at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1081) at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5033) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5320) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633) at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657) at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1637) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:619)
我的解决方案是在“MapperScannerConfigurer”配置为其指定“sqlSessionFactoryBeanName”,于是修改配置如下:
<!-- mybatis自动扫描包下的mapper --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.baofoo.admin.dao" /> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" /> <!-- 指定sqlSessionFactoryName --> </bean>
注:以上问题为本人在实战项目中解决问题的理解