[weld-dev] How to skip CDI injection if a property is not configured in batch application?

[Jozef Hartinger]

You can actually work around by listening to ProcessAnnotatedType and 
removing the @Inject annotation from injection points for which there is 
no value to inject. Is the set of defined key-value pairs known at the 
time when the CDI extension is called?

Jozef

On 03/09/2015 07:25 AM, Jozef Hartinger wrote:
> Adding weld-dev.
>
> Hi Cheng,
>
> by defining a producer method you are basically saying "I am able to 
> supply an object for this given type/qualifier combination". There is 
> not way to opt out of it at runtime. Are you concerned about the JVM 
> default values or the default values a user has provided?
>
> Jozef
>
> On 03/07/2015 05:54 PM, Cheng Fang wrote:
>> Hi Jozef,
>>
>> I'm having a question in using CDI injection in project JBeret (batch 
>> impl project), and would appreciate any help from you.
>>
>> A batch application (in Java SE or EE) can inject configured batch 
>> properties into batch artifact classes:
>>
>> @Inject
>> @javax.batch.api.BatchProperty(name = "batchPropName")
>> String batchPropName = "default name";
>>
>> The property value comes from job.xml, which is the batch job 
>> definition descriptor file:
>>
>> <batchlet ref="batchlet1">
>>         <properties>
>>                <property name="batchPropName" value="configured name"/>
>>         </properties>
>> ...
>>
>> When "batchPropName" property is not configured in job.xml, the 
>> injection should not happen, and whatever java default field value 
>> should be preserved for batchPropName field.
>>
>> With our current batch CDI extension [1] and producer bean [2], it 
>> injects a null value into this field, overwriting the java default 
>> value, when the target batch property is not present.
>>
>> How to signal to Weld to skip performing the injection for those 
>> injection targets?  Ideally, I hope it can be done from within 
>> producer methods, which is the place we retrieve batch properties and 
>> know whether they exist or not.
>>
>> I think this is also how Java EE field injection works.  How do we 
>> handle it in EE, and is it something I can mirror?
>>
>> Thanks,
>> Cheng
>>
>> [1] 
>> https://github.com/jberet/jsr352/blob/master/jberet-core/src/main/java/org/jberet/creation/BatchCDIExtension.java
>>
>> [2] 
>> https://github.com/jberet/jsr352/blob/master/jberet-core/src/main/java/org/jberet/creation/BatchBeanProducer.java
>>
>>
>
>
>
> _______________________________________________
> weld-dev mailing list
> weld-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/weld-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/weld-dev/attachments/20150309/11822cd5/attachment-0001.html