Child web application context could not access the property-placeholder defined in parent application context [SPR-8994]

[spring-projects-issues]

Simon Wong opened SPR-8994 and commented

If the properties files are defined using <context:property-placeholder /> at parent context, the child application context (typically the web application context) could not access it.

e.g. In ServiceImpl defined in parent application context

 @Value("${testString}") could refer to the property value in the properties file

 In WebController, defined in child web application context

 @Value("${testString}") would returns null

However, everything works fine if refer to the property using explicit bean ID

i.e. <util:properties id="someProperties" location="..." />
     and @Value("#{someProperties.testString}")

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Affects: 3.0.7, 3.1 GA

[spring-projects-issues]

Chris Beams commented

Hi Simon,

Actually this is by design. PropertyPlaceholderConfigurer (and in Spring 3.1, PropertySourcesPlaceholderConfigurer are BeanFactoryPostProcessor types, and these are not inherited by children in hierarchical application contexts. You'll need to explicitly re-define the PPC in the child context, or perhaps programmatically copy all BFPPs from parent->child.

[spring-projects-issues]

Simon Wong commented

Although it looks weird, especially using PropertyPlaceholderConfigure in multi-maven modules of Spring Roo, at least I know it is not inherit by design.
However, it seems that it hasn't been mentioned in reference document and JavaDoc. Would it be nicer if this behavior are mentioned in these documents?

[spring-projects-issues]

Chris Beams commented

Hi Simon,

From http://static.springsource.org/spring/docs/3.1.x/reference/html/beans.html#beans-factory-extension-factory-postprocessors

Also, BeanFactoryPostProcessors are scoped per-container. This is only relevant if you are using container hierarchies. If you define a BeanFactoryPostProcessor in one container, it will only be applied to the bean definitions in that container. Bean definitions in one container will not be post-processed by BeanFactoryPostProcessors in another container, even if both containers are part of the same hierarchy.