(转)Spring注入bean失败Failed to convert property value of type
Failedtoconvertpropertyvalueoftype[$Proxy13
Failedtoconvertpropertyvalueoftype[$Proxy13]torequiredtype
PropertyAccessException1:org.springframework.beans.TypeMismatchException:Failedtoconvertpropertyvalueoftype[$Proxy13]torequiredtype[com.makeprogress.dao.AuthorDaoImp]forproperty'authorDaoImp';nestedexceptionisjava.lang.IllegalArgumentException:Cannotconvertvalueoftype[$Proxy13]torequiredtype[com.makeprogress.dao.AuthorDaoImp]forproperty'authorDaoImp':nomatchingeditorsorconversionstrategyfound
Causedby:
org.springframework.beans.PropertyBatchUpdateException;nestedPropertyAccessExceptiondetails(1)are:
PropertyAccessException1:
org.springframework.beans.TypeMismatchException:Failedtoconvertpropertyvalueoftype[$Proxy13]torequiredtype[com.makeprogress.dao.AuthorDaoImp]forproperty'authorDaoImp';nestedexceptionisjava.lang.IllegalArgumentException:Cannotconvertvalueoftype[$Proxy13]torequiredtype[com.makeprogress.dao.AuthorDaoImp]forproperty'authorDaoImp':nomatchingeditorsorconversionstrategyfound
Causedby:
java.lang.IllegalArgumentException:Cannotconvertvalueoftype[$Proxy13]torequiredtype[com.makeprogress.dao.AuthorDaoImp]forproperty'authorDaoImp':nomatchingeditorsorconversionstrategyfound
atorg.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:231)
atorg.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:138)
atorg.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:815)
当系统出现类似上面的异常信息时,很可能你引用了已经实现了自动代理的Bean,Cannotconvertvalueoftype[$Proxy13]torequiredtype[com.makeprogress.dao.AuthorDaoImp]forproperty'authorDaoImp'提示的意思:你将authorDaoImp注入到一个spring受管Bean中,但是spring容器提示你注入的Bean类型不对,它说你注入的是[$Proxy13]类型,这就说明你可能在无意中将authorDaoImp实现了代理,此时你再在spring容器中引用authorDaoImp时得到的将是代理类型。示例如下(在数据源,事务管理器配置完整的前提下):
<beanid="authorDaoImp"class="com.makeprogress.dao.AuthorDaoImp">
<propertyname="hibernateTemplate">
<refbean="hibernateTemplate"/>
</property>
</bean>
<beanid="userLoginBo"class="com.makeprogress.bo.UserLoginBo">
<propertyname="authorDaoImp">
<refbean="authorDaoImp"/>
</property>
</bean>
<!--配置事务管理器-->
<beanid="transactionManager"class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<propertyname="sessionFactory"ref="sessionFactory"/>
</bean>
<!--配置事务拦截bean-->
<beanid="transactionInterceptor"class="org.springframework.transaction.interceptor.TransactionInterceptor">
<!--事务拦截bean需要注入一个事务管理器-->
<propertyname="transactionManager"ref="transactionManager"/>
<propertyname="transactionAttributes">
<props>
<propkey="insert*">PROPAGATION_REQUIRED</prop>
<propkey="find*">PROPAGATION_REQUIRED</prop>
<propkey="add*">PROPAGATION_REQUIRED</prop>
<propkey="save">PROPAGATION_REQUIRED</prop>
<propkey="Print*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>
<beanclass="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<propertyname="beanNames">
<value>validateUserBean,authorDaoImp</value>
</property>
<propertyname="interceptorNames">
<list>
<value>transactionInterceptor</value>
<!--
此处增加新的Interceptor
-->
</list>
</property>
</bean>
上面红色显示的authorDaoImp对象注入给了userLoginBo受管Bean,但是下面的配置中spring为authorDaoImp生成了自动代理,所以在上面的注入中注入的将是代理对象(提示信息中的[$Proxy13])而不是原来的authorDaoImp对象,这就产生了上面错误信息。
这种异常根据其产生的原因可以用下面二种方法解决:
如果异常产生原因是你将代理Bean注入给了其它受管Bean
1.将自动生成代理的authorDaoImp的配置去掉.
2.在接受注入的Bean中,将注入Bean类型改为它的接口类型.
3.不要将自动生成了代理的Bean注入给其它受管Bean.
如果异常产生原因是使用getBean("")方法产生时
2.不获得自动生成了代理的Bean.
3.在使用XXX.getBean("")方法得到生成了自动代理的受管Bean时,使用它的接口为其造型.