Spring - Weird Error in Bean Creation

Question

Any idea why I am getting this exception? ``` Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myService' defined in class path resource [context.xml]: Initialization of bean failed; nested exception is org.springframework.beans.TypeMismatchException: Failed to convert property value of type [$Proxy54 implementing org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised,net.sf.cglib.proxy.Factory,org.springframework.beans.factory.InitializingBean] to required type [com.mycompany.service.dao.MyDAO] for property 'myDAO'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [$Proxy54 implementing org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised,net.sf.cglib.proxy.Factory,org.springframework.beans.factory.InitializingBean] to required type [com.mycompany.service.dao.MyDAO] for property 'myDAO': no matching editors or conversion strategy found at org.springfra…

Accepted Answer

I suspect that if `ProdMiscDAO` was an interface (is it?) you would not have this error. I believe you probably have a class that is getting proxied using cglib under the hood, performing magic, etc. and in the end it cannot be safely cast to a paramter in a setter or constructor. Try programming to an interface and see if the error goes away.

Update: `ProdMiscDAO` is not an interface. It is a class that extends `SqlMappedClientDaoSupport`.

Given this, I recommend trying this:

- Rename `ProdMiscDAO` to `SqlMappedProdMiscDAO`.

- Extract an interface from `SqlMappedProdMiscDAO` named `ProdMiscDAO` (e.g. "`class SqlMappedProdMiscDAO implements ProdMiscDAO`")

- Go through all your code that uses `SqlMappedProdMiscDAO` and change it to use `ProdMiscDAO`.

- Configure spring to instantiate a `SqlMappedProdMiscDAO`, wiring it all the classes that need it.

This allows your DAO implementation to still extend `SqlMappedClientDaoSupport` but also to have an interface. After switching over all classes to use the interface instead of the class, Spring will not have to use cglib to proxy your DAO and the error should go away.

Spring - Weird Error in Bean Creation

Solution

Problem