[CAMEL-12291] Blueprint error: "name is already instanciated as null and cannot be removed"

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.19.4, 2.20.2
• Fix Version/s: 2.19.5, 2.20.3, 2.21.0
• Component/s: camel-blueprint

Environment

Mac OSX, Karaf 4.2.5

• Estimated Complexity: Unknown
• External issue URL: http://camel.465427.n5.nabble.com/Re-Blueprint-property-place-holder-error-name-is-already-instanciated-as-null-and-cannot-be-removed-td5817866.html
• Assignee: Claus Ibsen
• Reporter: Alex Soto
• Created: 23/Feb/18 19:33
• Updated: 05/Mar/18 14:34
• Resolved: 05/Mar/18 12:07

Description

The error "name is already instanciated (sic) as null and cannot be removed" is thrown when configuring a component in Blueprint using property placeholders.

I noticed when trying to migrate my project to Camel 2.20.2 (from 2.17.4) 
Example:

<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:camel="http://camel.apache.org/schema/blueprint"
xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.1.0"
xmlns:ext="http://aries.apache.org/blueprint/xmlns/blueprint-ext/v1.0.0"
xsi:schemaLocation="
              http://www.osgi.org/xmlns/blueprint/v1.0.0 
     https://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd”>
 
<cm:property-placeholder 
   persistent-id="audit.log"
   update-strategy="reload” 
   placeholder-prefix="#{" placeholder-suffix="}">

   <cm:default-properties>
      <cm:property name="audit-log.reaper.cron" value="0 0/30 * * * ?" />
      <cm:property name="startDelaySeconds" value="600" />
   </cm:default-properties>
</cm:property-placeholder>

 <bean id="audit-log-reaper-quartz" 
       class="org.apache.camel.component.quartz2.QuartzComponent">

    <property name="startDelayedSeconds" value="#{startDelaySeconds}" />
</bean>

 
The bean is referenced in a Camel route:

<route id="reaper-scheduler">
     <from uri="[audit-log-reaper-quartz://reaper?cron=\{{cron}}]" />

Throws exception:

org.osgi.service.blueprint.container.ComponentDefinitionException: Name audit-log-reaper-quartz is already instanciated as null and cannot be removed.
at org.apache.aries.blueprint.container.BlueprintRepository.removeRecipe(BlueprintRepository.java:131) [38:org.apache.aries.blueprint.core:1.8.3]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.updateUninstantiatedRecipes(BlueprintContainerImpl.java:572) [38:org.apache.aries.blueprint.core:1.8.3]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.processProcessors(BlueprintContainerImpl.java:559) [38:org.apache.aries.blueprint.core:1.8.3]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.doRun(BlueprintContainerImpl.java:394) [38:org.apache.aries.blueprint.core:1.8.3]
at org.apache.aries.blueprint.container.BlueprintContainerImpl.run(BlueprintContainerImpl.java:275) [38:org.apache.aries.blueprint.core:1.8.3]

 
 
Removing the property placeholder fixes the issue:
 

<bean id="audit-log-reaper-quartz" 
      class="org.apache.camel.component.quartz2.QuartzComponent">
  
      <property name="startDelayedSeconds" value="600" />
</bean>

 
According to Guillaume Nodet, this seems to have been introduced by this pull request:

https://github.com/apache/camel/commit/a4e94f036d02943814c84195d73837cf607c8c20

Solution proposed by Guillaume Nodet is to change line 1056 of /camel-blueprint/src/main/java/org/apache/camel/blueprint/handler/CamelNamespaceHandler.java

to

 if (camelContext.getComponent(component, false) == null) {

I tested this change locally and it seems to work, however I don't know if this can cause other problems.

Issue Links

• duplicates: CAMEL-12251 Do not hide (so much) blueprint.container.ComponentDefinitionException
• is broken by: CAMEL-10394 BlueprintCamelContext cannot find components created in RouteBuilder.configure method
• is related to: CAMEL-12251 Do not hide (so much) blueprint.container.ComponentDefinitionException