Using Environment Variables to filter PropertyPlaceholderConfigurer locations

[DeliveryNinja]

I have a remote service which manages all the properties files for all my Java applications, now this service has 3 instances, one for each of our environments, Development, Beta and Live.

I want to be able to provide the base URL for the remote locations using Windows/Linux environment variables but I'm running in to some problems.

  	<bean name="databaseProperties" class="com.idna.config.springsupport.BasicHttpAuthenticatedUrlResource">
		<constructor-arg value="http://${CONFIG_SERVICE}/properties/databases.xml" />
		<property name="credentials" ref="autowiredCredentials" />
	</bean>
	
        <bean name="loggingProperties" class="com.idna.config.springsupport.BasicHttpAuthenticatedUrlResource">
		<constructor-arg value="http://${CONFIG_SERVICE}/properties/logging.xml" />
		<property name="credentials" ref="autowiredCredentials" />
	</bean>
	
	<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="locations">
			<list>
				<ref bean="databaseProperties" />
				<ref bean="loggingProperties" />
			</list>
		</property>
		<property name="ignoreResourceNotFound" value="true" />
		<property name="searchSystemEnvironment" value="true" />
		<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
	</bean>

	<bean class="com.idna.linkeddata.domain.PropertyTest" >
    	        <property name="configUrl" value="${CONFIG_SERVICE}" />
         	<property name="test" value="${corporate.database.username}" />
        </bean>

The problem I have is that I can load the environment variable CONFIG_SERVICE (a simple url) and inject it to my test bean (PropertyTest) when I hard code the URL's to databaseProperties and loggingProperties beans. But not if they are filtered as shown above because to load CONFIG_SERVICE I need to instantiates the PropertyPlaceholder but obviously I can't do this without filtering the locations first. It's a catch 22.

I have tried adding another property placeholder but this will overwrite the one I want and not provide any of the remote locations.

Any ideas ?

Thanks

[objectamit]

instead of using the expression ${CONFIG_SERVICE} to access an environment variable CONFIG_SERVICE, use the Spel expression #{systemProperties['CONFIG_SERVICE']}. Also remember to read the online documentation here

[DeliveryNinja]

This doesn't work as the SPEL doesn't seem to get a handle on the windows environment variables such as CONFIG_SERVICE , JAVA_HOME or Path. I've tried it programmatically and using annotations. It resolves the expression and returns an empty string. I am using spring 3.1 so SPEL works, it is just not retrieving windows environment variables.

Just to test I have 1 bean created and autowire it in a test class.

	

    <bean class="com.idna.linkeddata.domain.PropertyTest" >
    	<property name="configUrl" value="#{ systemProperties['CONFIG_SERVICE'] }" />
    	<property name="random" value="#{ T(java.lang.Math).random() * 100.0 }" />
    </bean>

configUrl comes out as null, random works as expected.

[objectamit]

I ain't sure about windows as I don't have a Windows machine but it should work for sure. How are you defining environment variables in windows? one difference might be the use of

<contextroperty-placeholder>

which I assume that you're using. If instead using a

<bean>

approach, can you also try other approach and confirm?

[DeliveryNinja]

Okay so it was a quick fix.

Instead of using systemProperty I changed it to systemEnvironment and everything is working as expected.

Thanks for your help, much appreciated.

Here is my complete config for anyone that was interested.

	<!-- Properties Store Configuration --> 
  	
  	<bean name="databaseProperties" class="com.idna.config.springsupport.BasicHttpAuthenticatedUrlResource">
		<constructor-arg value="#{ systemEnvironment['CONFIG_SERVICE'] }properties/databases.xml" />
		<property name="credentials" ref="autowiredCredentials" />
	</bean>
	
        <bean name="loggingProperties" class="com.idna.config.springsupport.BasicHttpAuthenticatedUrlResource">
		<constructor-arg value="#{ systemEnvironment['CONFIG_SERVICE'] }properties/logging.xml" />
		<property name="credentials" ref="autowiredCredentials" />
	</bean>

	<bean name="autowiredCredentials"
		class="com.idna.config.springsupport.AuthenticationCredentials">
		<property name="username" value="username" />
		<property name="password" value="password" />
	</bean>
	
	<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" >
		<property name="locations">
			<list>
				<ref bean="databaseProperties" />
				<ref bean="loggingProperties" />
			</list>
		</property>
		<property name="ignoreResourceNotFound" value="true" />
		<property name="searchSystemEnvironment" value="true" />
		<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
	</bean>
	 
	<bean class="com.idna.linkeddata.domain.PropertyTest" >
    	    <property name="configUrl" value="#{ systemEnvironment['CONFIG_SERVICE'] }" />
    	    <property name="random" value="#{ T(java.lang.Math).random() * 100.0 }" />
    	    <property name="test" value="${corporate.database.username}" />
        </bean>