[CAMEL-16243] camel-restlet : Compatibility issue of camel-restlet with camel-api library resulting in e "NoSuchMethodError:org.apache.camel.CamelContext.getRestConfiguration(Ljava/lang/String;Z)Lorg/apache/camel/spi/RestConfiguration" in RestletComponent class

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Fix Version/s: 3.x
• Component/s: camel-restlet

Environment

Open JDK 11.0.2

• Estimated Complexity: Unknown
• Assignee: Unassigned
• Reporter: Pawan Mundhra
• Created: 21/Feb/21 08:50
• Updated: 21/Feb/21 18:16
• Resolved: 21/Feb/21 09:09

Description

 

Recently we upgraded our Application's overall camel version from 2.16.0 to 3.4.4. We are using several camel components in our applications such as:

camel-jms, camel-restlet, camel-restlet, cale-zookeeper, camel-file, camel-rest, etc...

 

One of the component we used in our Application was camel-restlet component (version 2.16.0) where after migration to camel 3.x, we are facing issue in service start-up.

Issue #1 : It seems camel removed the restlet component after 3.x. Could not find much documentation which would let us know how to migrate the existing camel-restlet component

Issue #2 : We gave a try to upgrade the camel-restlet component to 3.0.0-RC2. But during start-up of our service, we faced an error as mentioned in the below stack trace.

Exception in thread "main" java.lang.NoSuchMethodError: org.apache.camel.CamelContext.getRestConfiguration(Ljava/lang/String;Z)Lorg/apache/camel/spi/RestConfiguration;
        at org.apache.camel.component.restlet.RestletComponent.doStart(RestletComponent.java:215)
        at org.apache.camel.support.service.BaseService.start(BaseService.java:115)
        at org.apache.camel.impl.engine.AbstractCamelContext.startService(AbstractCamelContext.java:3026)
        at org.apache.camel.impl.engine.AbstractCamelContext.startServices(AbstractCamelContext.java:3032)
        at org.apache.camel.impl.engine.AbstractCamelContext.doStartCamel(AbstractCamelContext.java:2759)
        at org.apache.camel.impl.engine.AbstractCamelContext.doStartContext(AbstractCamelContext.java:2658)
        at org.apache.camel.impl.engine.AbstractCamelContext.doStart(AbstractCamelContext.java:2621)
        at org.apache.camel.support.service.BaseService.start(BaseService.java:115)
        at org.apache.camel.impl.engine.AbstractCamelContext.start(AbstractCamelContext.java:2453)
        at com.nri.csd.inf.console.service.GatewayService.startCamelContextIfNotStarted(GatewayService.java:201)
        at com.nri.csd.inf.console.service.GatewayService.postStart(GatewayService.java:100)
        at com.nri.csd.inf.console.service.AbstractLaunchableService.start(AbstractLaunchableService.java:216)
        at com.nri.csd.inf.console.ConsoleLauncher.main(ConsoleLauncher.java:96)

Found in the code that RestletComponent java class in camel-restlet-3.0.0-RC2 version has an API doStart() in which at line 215, there is a call to CamelContext class's method getRestConfiguration("restlet", true) (class in camel-api jar).

 

210    @Override
211    protected void doStart() throws Exception {
212        super.doStart();        
213   
214         // configure component options
215        RestConfiguration config = getCamelContext().getRestConfiguration("restlet", true);
216        // configure additional options on spark configuration
217        if (config.getComponentProperties() != null && !config.getComponentProperties().isEmpty()) {
218            setProperties(this, config.getComponentProperties());
219        }        
220            
221           cleanupConverters(enabledConverters);        
222              
223           component.start();     
2234   }

The API called at line 215 above (i.e. getRestConfiguration) seems to be removed from the class org.apache.camel.CamelContext in library camel-api during upgradation to 3.2 from 3.1.

Refer this https://camel.apache.org/manual/latest/camel-3x-upgrade-guide-3_2.html

 

However the above API in org.apache.camel.CamelContext in camel-api-3.0.0-RC2 is modified but I am having a transitive dependency upon camel-api-3.4 library (as we need to use camel-jms component as well) and it seems that both camel-api-3.4.4 and camel-api-3.0.0-RC2 cannot be kept together as it gives me some other error if both these libraries are present in the classpath.

java.lang.ClassNotFoundException: org.apache.camel.EndpointProducerResolver
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)

This is because the class org.apache.camel.EndpointProducerResolver is present in camel-api-3.4.4 but not present in camel-api-3.0.0-RC2. 

So it seems there is some cyclic dependency where I am trapped.

Please suggest what course of action can be taken for this issue with minimum impact or what is the compatibility of camel-restlet component and camel-api, camel-support libraries. We want all to be compatible with camel 3.4.4 version.