Unable to resolve placeholder when sourcing properties file in ApplicationContextInitializer

Question

I'm trying to programmatically set the .properties file for my Spring MVC application based on the profile. For example, if the profile is dev I'd like to source the database-dev.properties file.

So inside my web.xml I have it call out to my custom class

<servlet>
  <servlet-name>spring-web</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
  <init-param>
    <param-name>contextInitializerClasses</param-name>
    <param-value>com.galapagos.context.CustomEnvironmentApplicationContextInitializer</param-value>
  </init-param>
</servlet>

The custom class just looks at the current profile and adds the correct .properties file to environment's property sources

public class CustomEnvironmentApplicationContextInitializer
        implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    private static final Logger logger = LoggerFactory.getLogger(
        CustomEnvironmentApplicationContextInitializer.class);


    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        // Get the environment
        ConfigurableEnvironment environment = applicationContext.getEnvironment();

        try {

            profile = environment.getActiveProfiles()[0];

            String fileName = String.format(
                "database-%s.properties",
                profile);

            ResourcePropertySource resource = 
                new ResourcePropertySource(new ClassPathResource(fileName));

            environment.getPropertySources().addFirst(resource);
            logger.info("Loaded: " + resource);

        } catch (IOException e) {
            logger.warn("Error loading: " + e);
        }

        // Print the list of property sources
        logger.info("ENVIRONMENT: " + environment.getPropertySources());

        // Refresh the context - is this even needed??
        applicationContext.refresh();
    }


}

I can tell the above is working because it prints out the property sources at the bottom

2017-01-29 21:43:25 INFO  CustomEnvironmentApplicationContextInitializer:66 - ENVIRONMENT: [class path resource [database-dev.properties],servletConfigInitParams,servletContextInitParams,jndiProperties,systemProperties,systemEnvironment]

All the database-%{xxx}.properties files for each profile are pretty straightforward. Just some JDBC connection properties

jdbc.driverClassName=org.postgresql.Driver
jdbc.url=jdbc:postgresql://localhost:5432/galapagos
jdbc.username=my_user
jdbc.password=

And finally inside my servlet definition I load the resources and create a dataSource

<beans:bean
  class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
</beans:bean>

<!-- Database / JDBC -->

<beans:bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
  <beans:property name="driverClassName" value="${jdbc.driverClassName}" />
  <beans:property name="url" value="${jdbc.url}" />
  <beans:property name="username" value="${jdbc.username}" />
  <beans:property name="password" value="${jdbc.password}" />
</beans:bean>

However I'm getting a failure because it can't resolve the placeholder names

Could not resolve placeholder 'jdbc.driverClassName' in string value "${jdbc.driverClassName}"; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'jdbc.driverClassName' in string value "${jdbc.driverClassName}"

Looking around at various examples, they all seem to use this sort of set up (here's one). Any reason the placeholders aren't taking effect?

Thanks!

Answer 1

Was able to self-diagnose the issue here.

My thought was that the PropertyPlaceholderConfigurer class would go through my environment sources and source each file I had in there.

Apparently that's been replaced since Spring 3.1 with a new class - PropertySourcesPlaceholderConfigurer.

From the docs for PropertySourcesPlaceholderConfigurer -

This class is designed as a general replacement for PropertyPlaceholderConfigurer in Spring 3.1 applications

So I updated my servlet XML file to be -

<beans:bean
  class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">