HotswapSpringInvocationHandler cannot be cast to org.apache.cxf.frontend.ClientProxy

[folfix]

Hi!
I am struggling with a following exception:

Caused by: java.lang.ClassCastException: org.hotswap.agent.plugin.spring.getbean.HotswapSpringInvocationHandler cannot be cast to org.apache.cxf.frontend.ClientProxy
	at org.apache.cxf.frontend.ClientProxy.getClient(ClientProxy.java:127)
	at com.company.ExampleClass.afterPropertiesSet(ExampleClass.java:40)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1837)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1774)
	... 183 common frames omitted

org.apache.cxf.frontend.ClientProxy:107 (org.apache.cxf:cxf-rt-frontend-simple:3.2.8)

Hotswap start logs

HOTSWAP AGENT: 11:29:34.513 INFO (org.hotswap.agent.HotswapAgent) - Loading Hotswap agent {1.2.0} - unlimited runtime class redefinition.
HOTSWAP AGENT: 11:29:35.332 INFO (org.hotswap.agent.config.PluginRegistry) - Discovered plugins: [Hotswapper, JdkPlugin, WatchResources, ClassInitPlugin, AnonymousClassPatch, Hibernate, Hibernate3JPA, Hibernate3, Spring, Jersey1, Jersey2, Jetty, Tomcat, ZK, Logback, Log4j2, MyFaces, Mojarra, Omnifaces, Seam, ELResolver, WildFlyELResolver, OsgiEquinox, Owb, Proxy, WebObjects, Weld, JBossModules, ResteasyRegistry, Deltaspike, GlassFish]

Environment

Version 1.1.0-SNAPSHOT is working fine. Problem occurs for all of the versions newer than that.

• JDK: Oracle Java 1.8.0_181-b13
• DCEVM: 8u181-build2
• Multi-module Maven project
• Apache Tomcat/9.0.29 (war deployment)
• Spring Core 5.1.9.RELEASE - without Spring Boot
• cxf-core 3.2.8
• Linux Mint 19.2 4.18.0-25-generic

org.apache.cxf.frontend.ClientProxy:107 (org.apache.cxf:cxf-rt-frontend-simple:3.2.8)
but for version 1.1.0-SNAPSHOT

Thank you in advance!

[skybber]

It looks that you directly call https://github.com/apache/cxf/blob/b6e9e297a253e8b6e285e009d57ab8964065939a/rt/frontend/simple/src/main/java/org/apache/cxf/frontend/ClientProxy.java#L126
but HA creates proxy for com.sun.proxy https://github.com/HotswapProjects/HotswapAgent/blob/master/plugin/hotswap-agent-spring-plugin/src/main/java/org/hotswap/agent/plugin/spring/getbean/ProxyReplacer.java#L86

the code in ClientProxy should look something like:

(ClientProxy)Proxy.getInvocationHandler(((HotswapSpringInvocationHandler )Proxy.getInvocationHandler(o)).getTarget())

You can't modify CXF code, but you could modify the call. Would you like check it please by modification the call from your app :

ClientProxy.getClient(Proxy.getInvocationHandler(o))

does it help?

We can add some abstract mechanism to unwrap com.sun.proxy to avoid cross dependecne between plugins in the furure.

[folfix]

Thanks for response skybber.
Yes, it's direct call:

TlsCertificateFixer.disableCertificateCheck((HTTPConduit) (ClientProxy.getClient(wsClient).getConduit()));

I invoked following in debuger:

• ((Proxy) wsClient).h -> returns HotswapSpringInvocationHandler
• ClientProxy.getClient(wsClient.h.getTarget()) -> returns unwrapped client
• TlsCertificateFixer.disableCertificateCheck(ClientProxy.getClient(((Proxy) wsClient).h.getTarget()).getConduit()) -> is equal to original code

Unfortunately I am not able to import HA sources and test if changes compatible with HA will either work with plain Hotspot JVM. I guess they will not.

I found workaround to be able to use HA 1.3.1-SNAPSHOT and I will wait patiently for mentioned abstract mechanism :)

Thanks!

[ruediste]

I wanted to add a Transformer to patch java.lang.reflect.Proxy.getInvocationHandler(Object) to return the original invocation handler. I set a breakpoint in ProxyReplacer#86 but it was never reached in the unit tests. Do you know how to get spring to use Proxy to create proxies?