Overriding Spring #PropertySource by #Import - spring

Question

I have a property test=default in class DefaultConfig, and I'm making them available using #PropertySource annotation.
#Configuration
#PropertySource("classpath:default.properties")
public class DefaultConfig {}
I then want to be able to override to test=override, which is in a different properties file in class OverrideConfig, so I again use #PropertySource.
#Configuration
#Import(DefaultConfig.class)
#PropertySource("classpath:override.properties")
public class OverrideConfig {}
I configure a test to prove that it works.
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes={OverrideConfig.class})
public class TestPropertyOverride {
#Autowired
private Environment env;
#Test
public void propertyIsOverridden() {
assertEquals("override", env.getProperty("test"));
}
}
Except of course it does not.
org.junit.ComparisonFailure: expected:<[override]> but was:<[default]>
Maxing out debug, I can see what's happening:
StandardEnvironment:107 - Adding [class path resource [default.properties]] PropertySource with lowest search precedence
StandardEnvironment:107 - Adding [class path resource [override.properties]] PropertySource with lowest search precedence
It seems backwards. Am I making a simple mistake or misthinking this, or would you expect the properties defined by an #PropertySource in an #Import-ed configuration class to be overridden by properties defined in am #PropertySource in the #Import-ing class?

Answer 1

Here is a solution by Helder Sousa, written as a comment of the JIRA issue created by the OP:
[T]he behaviour available in spring xml (one xml importing another xml) is achievable using nested configurations:
#Configuration
#PropertySource("classpath:default.properties")
public class DefaultConfig {}
#Configuration
#PropertySource("classpath:override.properties")
public class OverrideConfig {
#Configuration
#Import(DefaultConfig.class)
static class InnerConfiguration {}
}
With this setup, the properties will be gather in the proper order.

Answer 2

Today with Spring 4 you can use this:
#TestPropertySource(value="classpath:/config/test.properties")
And this can be used to use and eventually override properties for the junit test:
#RunWith(SpringJUnit4ClassRunner.class)
#TestPropertySource(value="classpath:/config/test.properties")

Answer 3

I'm currently struggling with a similar case in Spring 3.1 but I'm using a different approach to override properties, because #PropertySource does not support optional property files:
#Configuration
#PropertySource("classpath:default.properties")
public class BaseConfig {
#Inject
private ApplicationContext context;
#PostConstruct
public void init() throws IOException {
Resource runtimeProps = context.getResource("classpath:override.properties");
if (runtimeProps.exists()) {
MutablePropertySources sources = ((ConfigurableApplicationContext) context).getEnvironment().getPropertySources();
sources.addFirst(new ResourcePropertySource(runtimeProps));
}
}
...
It seems that #Import does not cause any specific order of #Configuration instantiation whatsoever besides the order dictated by normal bean dependencies. A way to force such an order is to inject the base #Configuration instance itself as a dependency. Could you try:
#Configuration
#Import(DefaultConfig.class)
#PropertySource("classpath:override.properties")
public class OverrideConfig {
#Inject
private DefaultConfig defaultConfig;
...
}
Does this help?
And maybe the new ContextHierarchy annotation could be of help here also but I didn't try this one out so far.

Answer 4

You could enforce the loading order of your properties like this:
#Configuration
#PropertySource(value={"classpath:default.properties","classpath:override.properties"})
public class OverrideConfig {
...
}

Answer 5

I had a similar problem and succeeded in just declaring also the default property in my custom configuration:
#Configuration
#Import(DefaultConfig.class)
#PropertySource({"classpath:default.properties", "classpath:override.properties"})
public class OverrideConfig {}