啟動報錯：Error creating bean with name ‘userServiceImpl’ defined in class path resource [applicationContext.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.sun.proxy. P r o x y 10 i m p l e m e n t i n g d e m o . s s h . d a o . U s e r s D a o , o r g . s p r i n g f r a m e w o r k . a o p . S p r i n g P r o x y , o r g . s p r i n g f r a m e w o r k . a o p . f r a m e w o r k . A d v i s e d ′ t o r e q u i r e d t y p e ′ d e m o . s s h . d a o I m p l . U s e r s D a o I m p l ′ f o r p r o p e r t y ′ d a o ′ ; n e s t e d e x c e p t i o n i s j a v a . l a n g . I l l e g a l S t a t e E x c e p t i o n : C a n n o t c o n v e r t v a l u e o f t y p e [ c o m . s u n . p r o x y . Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised' to required type 'demo.ssh.daoImpl.UsersDaoImpl' for property 'dao'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy. Proxy10implementingdemo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised′torequiredtype′demo.ssh.daoImpl.UsersDaoImpl′forproperty′dao′;nestedexceptionisjava.lang.IllegalStateException:Cannotconvertvalueoftype[com.sun.proxy.Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [demo.ssh.daoImpl.UsersDaoImpl] for property ‘dao’: no matching editors or conversion strategy found
完整報錯代碼：
八月 05, 2019 4:14:45 下午 org.apache.catalina.core.StandardContext listenerStart
嚴重: Exception sending context initialized event to listener instance of class [org.springframework.web.context.ContextLoaderListener]
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userServiceImpl' defined in class path resource [applicationContext.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.sun.proxy.$Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised' to required type 'demo.ssh.daoImpl.UsersDaoImpl' for property 'dao'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy.$Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [demo.ssh.daoImpl.UsersDaoImpl] for property 'dao': no matching editors or conversion strategy found
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:835)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:446)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:328)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4579)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5041)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:742)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:718)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:703)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1142)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1876)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:112)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:1054)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:428)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1586)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:308)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:424)
at org.apache.catalina.util.LifecycleBase.setState(LifecycleBase.java:367)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:966)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:839)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1427)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1417)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:943)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:258)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:770)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.startup.Catalina.start(Catalina.java:682)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:353)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:493)
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.sun.proxy.$Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised' to required type 'demo.ssh.daoImpl.UsersDaoImpl' for property 'dao'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy.$Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [demo.ssh.daoImpl.UsersDaoImpl] for property 'dao': no matching editors or conversion strategy found
at org.springframework.beans.AbstractNestablePropertyAccessor.convertIfNecessary(AbstractNestablePropertyAccessor.java:591)
at org.springframework.beans.AbstractNestablePropertyAccessor.convertForProperty(AbstractNestablePropertyAccessor.java:603)
at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:204)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1527)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1486)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1226)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
... 52 more
Caused by: java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy.$Proxy10 implementing demo.ssh.dao.UsersDao,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [demo.ssh.daoImpl.UsersDaoImpl] for property 'dao': no matching editors or conversion strategy found
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:302)
at org.springframework.beans.AbstractNestablePropertyAccessor.convertIfNecessary(AbstractNestablePropertyAccessor.java:576)
... 58 more
原因：很明顯，配置檔案生成bean錯誤，是什麼原因呢？原來是擷取類的時候出錯。Spring是面向接口程式設計，是以不能用實 現類來得到bean，而應該用接口得到bean對象。
applicationContext配置:
<bean id="usersDaoImpl" class="demo.ssh.daoImpl.UsersDaoImpl">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
<bean id="userServiceImpl" class="demo.ssh.serviceImpl.UserServiceImpl">
<property name="dao" ref="usersDaoImpl"></property>
</bean>
擷取bean:
public class UserServiceImpl implements UserService{
//用接口，不能用實作類
private UsersDao dao;
public void setDao(UsersDao dao) {
this.dao = dao;
}
}
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