Document purpose of name attribute in @PropertySource

[manueljordan]

In Spring Framework, for the @PropertySource, according with its API or javadoc it has the name attribute

Indicate the name of this property source. 
If omitted, the factory() will generate a name based on the underlying resource 
(in the case of DefaultPropertySourceFactory: 
derived from the resource description through a 
corresponding name-less ResourcePropertySource constructor).

Ok, is clear that is possible define the name such as:

    @PropertySource(name="infra", 
                    value={"classpath:/com/.../infrastructure.properties"})

But How and where use that name? What is its purpose?

It was reported at SO at:

• Spring Framework: How and where use the "name" of the @PropertySource?

The comment is valid, but would be nice if can be expanded at both Spring Reference documentation and javadoc

[anii1827]

hi @manueljordan,

This will provide more clarity for the name attribute of the @PropertySource annotation.

MutablePropertySources will provide to get specific properties file by name provided in @PropertySource annotation.

@Autowired
Environment env;

MutablePropertySources sources = ((ConfigurableEnvironment)env).getPropertySources();
PropertySource<?> propertySource = sources.get("infra");
Object property = propertySource.getProperty("name.value");
System.out.println(property);

[sbrannen]

To summarize what's been stated on Stack Overflow and above by @anii1827...

The name of a PropertySource serves two general purposes.

1. diagnostics: to determine the source of the properties in logging and debugging
2. programmatic interaction with MutablePropertySources: the name can be used to retrieve properties from a particular property source (or to determine if a particular named property source already exists). The name can also be used to add a new property source relative to an existing property source (see the addBefore() and addAfter() methods).

Note that this issue has been assigned the documentation label.

[anii1827]

hi @sbrannen
I would like to contribute to this.
can you assign to me?

[manueljordan]

Thanks to both the valuable feedback. Now has more sense.

[sbrannen]

Hi @anii1827,

I would like to contribute to this. can you assign to me?

That's very kind of you to offer!

Unfortunately, I had already started on this issue (see 49a4ed2), and I drafted the text I plan to include in #30195 (comment).

In light of that, it's easier if I keep this issue assigned to me.

Cheers,

Sam

[manueljordan]

Sam, just being curious your point (2) is already explained by the valuable comment of anii1827 - but could you pls add a simple snipet code about your point (1)? I want understand very well that point - If I understand correctly, if exists the db.url property, through the point (1) is possible to know from what .properties file comes from?, Am I correct?

[sbrannen]

@manueljordan, core Spring Framework does not provide any direct mechanism for linking a specific property to a PropertySource.

Rather, that's a feature of Spring Boot: org.springframework.boot.origin.PropertySourceOrigin.

Spring Boot uses its Origin abstraction in several places for logging and diagnostics.