@Component class using @Value cannot access @PropertySource proeprties [SPR-8516]

[spring-projects-issues]

Marcel Overdijk opened SPR-8516 and commented

I'm using a @Configuration class like:

@Configuration
@ComponentScan(basePackages = {"nl.vooty"}, excludeFilters = {@Filter(type = FilterType.ANNOTATION, value = Configuration.class)})
@PropertySource("classpath:/META-INF/config.properties")
public class AppConfig {
    ..
}

In a @Component class I would like to inject a property value using the @Value annotation like:

@Component
public class AuthenticationFailureBadCredentialsListener implements ApplicationListener<AuthenticationFailureBadCredentialsEvent> {
    
    @Value("${authentication.max.login.failures}")
    private String maxLoginFailures;

    ..
}

Although the property exists, it's not injected in the variable.

When logging the value of the maxLoginFailures it is: "${authentication.max.login.failures}"

Note that I'm testing on M2.

---

Affects: 3.1 M2

Issue Links:

• automatic registration of PSPC when @PropertySource is used [SPR-8539] #13183 automatic registration of PSPC when @PropertySource is used

[spring-projects-issues]

Chris Beams commented

Hi Marcel,

This is actually as designed. Replacement of ${...} placeholders, whether in XML 'value' attributes or in @Value annotations must be done with a PropertyPlaceholderConfigurer or PropertySourcesPlaceholderConfigurer. The latter is aware of the Environment and thus any registered PropertySources. The latter is registered by default when using <context:property-placeholder/> under Spring 3.1. You can of course also register this as a @Bean, but it is recommended to declare the method as static. See @Bean annotation Javadoc for details why.

[spring-projects-issues]

Marcel Overdijk commented

OK Chris, my bad.
Was in the wrong impression that this was configured automagically.

Defining

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
    return new PropertySourcesPlaceholderConfigurer();
}

works perfectly.

[spring-projects-issues]

Chris Beams commented

Great!

[spring-projects-issues]

Mikhail Tokarev commented

Chris,

Why a replacement of ${...} placeholders for Resource type using @Value annotation works fine?

@Controller
public class MyController {

    @Value("${some.path}")
    private Resource resources;

i'm using spring 3.1.1.RELEASE

[spring-projects-issues]

Chris Beams commented

Mikhail,

I'm not sure exactly what you're asking here. Can you elaborate? Thanks.

[spring-projects-issues]

Mikhail Tokarev commented

I'm using @Configuration class like:

@Configuration
@PropertySource("classpath:/config.properties")
public class AppConfig {
    ...
}

In a @Component class I use @Value annotations like:

@Component
public class MyComponent {
    @Value("${folderPath}")
    private Resource folderPath;

    @Value("${propertyValue}")
    private String propertyValue;
}

My config.properties file:

folderPath=file:/tmp
propertyValue=test

The value of the propertyValue it is: "${propertyValue}". But the value of the folderPath it is: "file:/tmp".

[spring-projects-issues]

Chris Beams commented

Right. Have you added a PropertySourcesPlaceholderConfigurer @Bean as mentioned above?

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
    return new PropertySourcesPlaceholderConfigurer();
}

This is also described in @Bean Javadoc. See "A note on BeanFactoryPostProcessor-returning @Bean methods".

[spring-projects-issues]

Mikhail Tokarev commented

No, I have not added PSPC. I understand why it does not work for String, but I do not understand why it works for Resource.

[spring-projects-issues]

Chris Beams commented

Sorry Mikhail, I misunderstood your question. The reason it works by default for Resource is because ResourceEditor is at work here. ResourceEditor is, as of 3.1, aware of PropertySources via the PropertyResolver interface (which is ultimately your ApplicationContext's Environment).

So the @PropertySource you register up top is automatically being considered by ResourceEditor. Hope that helps!

[spring-projects-issues]

Mikhail Tokarev commented

ok, I see. In my opinion this is not an explicit behavior and I would like at this specify.
Thank you.