Issue with @Transactional on a public method in a Class used by CXF

Question

I'm mixing spring-data and CXF to create a RESTful endpoint that creates neo4j nodes. My structure is a set Interfaces which define the public facing methods, and my implementations which have several private methods under that are called by my public methods.

When I do create a public method, I get a proxy casting issue.

Caused by: java.lang.IllegalArgumentException: Can not set javax.ws.rs.core.HttpHeaders field com.neuralsandbox.service.PublicCallsPublic.httpHeaders to $Proxy37
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:146)
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:150)
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:37)
at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:57)
at java.lang.reflect.Field.set(Field.java:657)
at org.apache.cxf.jaxrs.utils.InjectionUtils.injectFieldValue(InjectionUtils.java:170)
at org.apache.cxf.jaxrs.utils.InjectionUtils.injectContextProxiesAndApplication(InjectionUtils.java:921)
at org.apache.cxf.jaxrs.JAXRSServerFactoryBean.injectContexts(JAXRSServerFactoryBean.java:365)
at org.apache.cxf.jaxrs.JAXRSServerFactoryBean.updateClassResourceProviders(JAXRSServerFactoryBean.java:391)
at org.apache.cxf.jaxrs.JAXRSServerFactoryBean.create(JAXRSServerFactoryBean.java:151)
... 29 more

If I my spring-tx <tx:annotation-driven proxy-target-class="true" /> I get the following exception:

Caused by: org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class $Proxy32]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Cannot subclass final class class $Proxy32
at org.springframework.aop.framework.Cglib2AopProxy.getProxy(Cglib2AopProxy.java:213)
at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:112)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.createProxy(AbstractAutoProxyCreator.java:476)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:362)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:322)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:407)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.postProcessObjectFromFactoryBean(AbstractAutowireCapableBeanFactory.java:1598)
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:162)
... 41 more
Caused by: java.lang.IllegalArgumentException: Cannot subclass final class class $Proxy32
    at net.sf.cglib.proxy.Enhancer.generateClass(Enhancer.java:446)
    at net.sf.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33)
    at net.sf.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
    at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:216)
    at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
    at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:285)
    at org.springframework.aop.framework.Cglib2AopProxy.getProxy(Cglib2AopProxy.java:201)
    ... 48 more

I have a GitHub project which has the troubled code:

https://github.com/NicholasAStuart/broken-spring-neo4j-cxf.git

What is wrong with my code?

Answer 1

Is the @Transactional on a concrete class? If so, I'd suggest using the proxy-target-class="true" as that's intended for concrete classes.

Note if using CGLIB, the classes must not be final, be visible, and have a default (no argument) constructor.