[ARIES-1668] Support null values inside property-placeholders

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0
• Fix Version/s: blueprint-core-1.9.0, blueprint-cm-1.2.0
• Component/s: Blueprint
• Labels: blueprint
• Assignee: Guillaume Nodet
• Reporter: Valentin Aitken
• Created: 20/Jan/17 21:55
• Updated: 19/Dec/19 17:36
• Resolved: 25/Jan/18 13:05

Description

Scenario:
For a bean I'd like to supply property-placeholder with a default null value.

    <cm:property-placeholder persistent-id="org.apache.xxx.placeholder">
        <cm:default-properties>
            <cm:property name="foo.bar">
                <null/>
            </cm:property>
        </cm:default-properties>
    </cm:property-placeholder>
    <bean class="org.apache.xxx.FooImpl" id="xxx-id">
        <property name="fooBar" value="${foo.bar}"/>
    </bean>

package org.apache.xxx;
public class FooImpl {
  public void setFooBar(Integer fooBar) { this.fooBar = fooBar;}
  public Integer getFooBar() { return fooBar; }
}

Observed behaviour:

ERROR  17 o.a.a.b.c.BlueprintContainerImpl [rint Extender: 3] Unable to start blueprint container for bundle org.apache.xxx/0.x.0.SNAPSHOT
org.osgi.service.blueprint.container.ComponentDefinitionException: Error setting property: PropertyDescriptor <name: maxAge, getter: class org.apache.xxx.FooImpl.getFooBar(), setter: [class org.apache.xxx.FooImpl.setFooBar(class java.lang.Integer)]
  at org.apache.aries.blueprint.container.BeanRecipe.setProperty(BeanRecipe.java:963)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BeanRecipe.setProperties(BeanRecipe.java:929)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BeanRecipe.setProperties(BeanRecipe.java:910)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BeanRecipe.internalCreate2(BeanRecipe.java:844)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BeanRecipe.internalCreate(BeanRecipe.java:811)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.di.AbstractRecipe$1.call(AbstractRecipe.java:79)[17:org.apache.aries.blueprint.core:1.5.0]
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_111]
  at org.apache.aries.blueprint.di.AbstractRecipe.create(AbstractRecipe.java:88)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BlueprintRepository.createInstances(BlueprintRepository.java:255)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BlueprintRepository.createAll(BlueprintRepository.java:186)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BlueprintContainerImpl.instantiateEagerComponents(BlueprintContainerImpl.java:712)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BlueprintContainerImpl.doRun(BlueprintContainerImpl.java:399)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.container.BlueprintContainerImpl.run(BlueprintContainerImpl.java:273)[17:org.apache.aries.blueprint.core:1.5.0]
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_111]
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_111]
  at org.apache.aries.blueprint.container.ExecutorServiceWrapper.run(ExecutorServiceWrapper.java:106)[17:org.apache.aries.blueprint.core:1.5.0]
  at org.apache.aries.blueprint.utils.threading.impl.DiscardableRunnable.run(DiscardableRunnable.java:48)[17:org.apache.aries.blueprint.core:1.5.0]
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_111]
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_111]
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)[:1.8.0_111]
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)[:1.8.0_111]
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)[:1.8.0_111]
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)[:1.8.0_111]
  at java.lang.Thread.run(Thread.java:745)[:1.8.0_111]
Caused by: java.lang.NumberFormatException: For input string: ""
  at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)[:1.8.0_111]

Versions loaded in karaf

 | mvn:org.apache.aries.blueprint/org.apache.aries.blueprint.api/1.0.1
 | mvn:org.apache.aries.blueprint/org.apache.aries.blueprint.cm/1.0.7
 | mvn:org.apache.aries.blueprint/org.apache.aries.blueprint.core/1.5.0

My Analysis:
I discovered that org.osgi.service.blueprint.reflect.Metadata.NullMetadata.NULL set correctly on to the BeanProperty
However good work from context.parseElement(BeanProperty.class, enclosingComponent, e) is being vanished from props.addEntry(createValue(context, prop.getName(), String.class.getName()), prop.getValue());