找不到具有多个上下文的属性：property-placeholder

Question

I am using spring 3.1 with spring profiles to load the beans. In my app context file, I load the properties like :

<context:property-placeholder order="1"  location="classpath*:META-INF/spring/*_${spring.profiles.active}.properties" ignore-unresolvable="true"/>

And then I use the property value to load the data source bean like

<property name="driverClassName" value="${database.driverClassName}"/>

It works fine. The problem starts when I add a couple of more property placeholders so that properties from some database tables can be loaded.

This uses a properties reference loaded by

<bean id="configFactoryBean"
class="org.springmodules.commons.configuration.CommonsConfigurationFactoryBean">
   <constructor-arg ref="globalSystemConfiguration"/>
</bean>

To add to the details, this configFactoryBean uses the datasource to load the properties from the database.

When I do this, I have the following exception:

java.lang.ClassNotFoundException: ${database.driverClassName}

My analysis is that its trying to load the datasource before resolving the property from the first context property placeholder. I may be wrong. Or maybe spring profile variable is not resolved properly.

Can anyone please help me to fix this.

Thanks Akki

Answer 1

This bug about multiple property placeholders might relate to your problem: https://jira.spring.io/browse/SPR-9989

When using multiple PropertyPlaceholderConfigurer in conjunction with @Value annotation and default value for placeholders syntax (ie ${key:defaultValue} ), only the first PropertyPlaceholderConfigurer is used. If this configurer does not contain the desired value, it falls back to @Value default even if the second PropertyPlaceholderConfigurer contains the value.

Affects Version/s: 3.1.3

Answer 2

In my application I am using property-placeholder configurer in following way and it works very well. You can try that.

<bean id="propertyConfigurer"
          class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
          <property name="locations">
            <list>
                <value>classpath*:META-INF/spring/*_${spring.profiles.active}.properties</value>
            </list>
          </property>
    </bean>

I think this should resolve your problem. :)

Answer 3

Each <context:property-placeholder> creates a new instance of PropertyPlaceholderConfigurer - it gets messy easily. You should have one such thing per application and on application level, not on libraries' one - that makes maintenance much easier.

For more details and a suggestion how to cope with it look here: http://rostislav-matl.blogspot.cz/2013/06/resolving-properties-with-spring.html

Answer 4

Since you have suggested hardcoding the path to the configuration file works, try using the profiles attribute on the tag to selectively include the configuration.

<beans profile="profileName">
    <context:property-placeholder  order="1"  location="classpath*:META-INF/spring/hardcoded.properties" ignore-unresolvable="true"/>
</beans>

<beans profile="profileName2">    
    <context:property-placeholder order="1"  location="classpath*:META-INF/spring/hardcoded.properties" ignore-unresolvable="true"/>
</beans>

See this article explaining profiles: http://java.dzone.com/articles/using-spring-profiles-xml