Unable to use ehcache in pure blueprint DSL

[Mirek Borsky]

Greetings,

I am trying to use camel-ehcache with pure blueprint DSL and struggle to make 
it work. Could someone either help point me in the right direction or confirm 
that it is not possible?

I have done the following:
downloaded karaf 4.4.3, and Java 11, run the following in karaf concole:
feature:repo-add camel 3.20.2
feature:install camel
feature:install camel-ehcache

Then tried this route:

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0";>
    <camelContext xmlns="http://camel.apache.org/schema/blueprint"; 
id="CacheTest-ctx">
        <route id="CacheTest">
            <from uri="timer:onetime?repeatCount=1"/>
            <setBody>
                <constant>testbody</constant>
            </setBody>
            <setHeader name="CamelEhcacheKey">
                <constant>testkey</constant>
            </setHeader>   
            <to uri="ehcache:testcache?action=PUT"/>
            <setBody>
                <constant>empty</constant>
            </setBody>
            <to uri="ehcache:testcache?action=GET"/>
            <to uri="log:output?showAll=true"/>
        </route>
    </camelContext>
</blueprint>

The route run, but output showed that the key was not found in the cache (body 
was "empty" instead of "testbody").

I tried to add a sample xml configuration of the cache:
<config xmlns="http://www.ehcache.org/v3";>
    <cache alias="testcache">
        <key-type>java.lang.String</key-type>
        <value-type>java.lang.String</value-type>
        <expiry><ttl unit="seconds">30</ttl></expiry>
        <resources><heap unit="entries">10</heap></resources>
    </cache>
</config>

And used it in the route:
<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0";>
    <bean id="cacheConfigurationURL" class="java.net.URL">
        <argument value="file:deploy/ehcache.xml"/>
    </bean>
    <bean id="cacheConfigurationFile" class="org.ehcache.xml.XmlConfiguration">
        <argument ref="cacheConfigurationURL"/>
    </bean>
    <bean id="cacheManager" 
class="org.ehcache.config.builders.CacheManagerBuilder" 
factory-method="newCacheManager">
        <argument ref="cacheConfigurationFile"/>
    </bean>
    <camelContext xmlns="http://camel.apache.org/schema/blueprint"; 
id="CacheTest-ctx">
        <route id="CacheTest">
            <from uri="timer:onetime?repeatCount=1"/>
            <setBody>
                <constant>testbody</constant>
            </setBody>
            <setHeader name="CamelEhcacheKey">
                <constant>testkey</constant>
            </setHeader>   
            <to 
uri="ehcache:testcache?action=PUT&amp;cacheManager=#cacheManager"/>
            <setBody>
                <constant>empty</constant>
            </setBody>
            <to 
uri="ehcache:testcache?action=GET&amp;cacheManager=#cacheManager"/>
            <to uri="log:output?showAll=true"/>
        </route>
    </camelContext>
</blueprint>

but the route will not start up, providing java.lang.IllegalStateException: 
State is UNINITIALIZED exception.
I understand that cacheManager.init have to be called before the route start, 
but could this be done with just blueprint DSL? I can not create a dummy bean 
and call this as a factory-method, as it returns void. I can not call it in a 
separate route with lower startup order, as it is not fast enough.
Any suggestions?

Mirek Borský