+1, that is what we did in Johnzon and it makes usage smooth IMO.
Le 21 déc. 2014 12:08, "Oliver B. Fischer" <[email protected]> a
écrit :
> @Anatole: I would like to see this working even without any annotation by
> matching the bean property by its name with a configuration value.
> Annotations should be only needed if the default annotation free way is not
> working/is not flexible enough.
>
> WDYT?
>
> Bye,
>
> Oliver
>
>
> Am 18.12.14 um 00:05 schrieb Anatole Tresch:
>
>> Hi all
>> I would like to present another use case: injection of configuration in SE
>> (EE should be almost similar):
>>
>> Automatic Configuration (Configuration Injection)
>>
>> Tamaya must provide a feature for automatic configuration, where
>> properties
>> of a class or methods can be annotated:
>>
>> -
>>
>> Hereby the lifecycle of the instances configured should not be managed
>> by Tamaya.
>> -
>>
>> String as well as other types should be supported.
>> -
>>
>> It must be possible to define default values to be used, if no valid
>> value is present.
>> -
>>
>> It must be possible to define dynamic expressions, at least for
>> default
>> values.
>> -
>>
>> The values configured can be reinjected, if the underlying
>> configuration
>> changes. This should also be the case fir final classes, such as
>> Strings.
>> -
>>
>> Reinjection should be controllable by an loading policy.
>> -
>>
>> It should be possible to evaluate multiple keys, e.g. current keys,
>> and
>> as a backup deprecated keys from former application releases.
>> -
>>
>> It should be possible to evaluate multiple configurations.
>> -
>>
>> The type conversion of the properties injected should be configurable.
>> -
>>
>> The value evaluated for a property (before type conversion) may be
>> adaptable as well.
>> -
>>
>> It should be possible to observe configuration changes.
>>
>> To illustrate the points above imagine the following POJO:
>> Configured POJO Example
>>
>> *public* *class* *MyPojo* {
>> @ConfigProperty("myCurrency")
>> @DefaultValue("CHF") // use as default
>> @WithLoadingPolicy(LoadingPolicy.INITIAL) // load the value only
>> once (no reinjection)
>> *private* *String* currency;
>>
>> @ConfigProperty("myCurrencyRate")
>> *private* *Long* currencyRate;
>>
>> @ConfigProperty // evaluates to
>> key=<fieldName>="fullRate"
>> @ConfigProperty("fallback.property")
>> @WithConfig("default")
>> @WithConfig("moduleConfig");
>> *private* *BigDecimal* fullRate;
>>
>> // Configuration method
>> *void* setStartup(@ConfigProperty *boolean* startup,
>> @ConfigProperty("componentName") @WithConfig("module1")
>> @DefaultValue("N/A") *String* compName){
>> ...
>> }
>>
>> // Configuration method
>> @ConfigProperty("componentName")
>> @WithConfig("module1")
>> @DefaultValue("N/A")
>> *private* *void* setComponentName(*String* compName){
>> ...
>> }
>>
>> // Configuration listener method, defining which properties to listen
>> for
>> @ConfigChanges
>> @ConfigProperty("componentName")
>> *private* *void* setComponentName(ConfigChange change){
>> ...
>> }
>>
>> }
>>
>> The instance then can be passed for being configured:
>> Configuring a POJO
>>
>> MyPojo instance = *new* MyPojo();*Configuration*.configure(instance);
>>
>> This will configure all values according to the load policies (by
>> default
>> LoadPolicy.INITIAL). Depending on the listeners present and the properties
>> injected Tamaya will keep weak references to the bean and the current
>> environment, so it can be determined, when configuration changes must be
>> published into the bean.
>> Feel free to comment or ask questions ;)
>>
>> Best,
>> Anatole
>>
>>
> --
> N Oliver B. Fischer
> A Schönhauser Allee 64, 10437 Berlin, Deutschland/Germany
> P +49 30 44793251
> M +49 178 7903538
> E [email protected]
> S oliver.b.fischer
> J [email protected]
> X http://xing.to/obf
>
>
