javasmallryeeclipse-microprofile-config

How to use Jakarta microprofile configmapping for my own properties file?

Using Jakarta Microprofile Config one can read the contents of your application.properties (or microprofile-config.properties) into a Java type-safe datastructure based on interfaces.

So I have this (shortened) ConfigMapping definition:

@ConfigMapping(prefix="banana")
public interface BananaConfig {
    public String form();
}

And I want to populate this using the Jakarta Microprofile Config readers/converters from a self-supplied properties file, which is providing configuration for dynamically determined tenants (i.e. not available at start-up, so injecting the config will not work).

Apparently Jakarta Microprofile Config is only suitable for injecting a single configuration of Truth, not for reading willy-nilly properties files. The only options for customisation is in your own source readers (in the form of service loaders) or converters, but these still only allow for a Single Configuration.

Basically I want something like this to happen:

try (var is = Files.newInputStream(Path.of("tenant.properties")))
{
    BananaConfig config = JakartaConfig.of(new Properties().load(is));
    return config;
}
catch (IOException e)
{
    ...
}

Is there a way™ for this to happen? FYI: the platform we're working on is Quarkus, and under the hood it uses Smallrye Config.

Solution

  • So after fiddling around with the Smallrye code we came up with this solution:

    var propertiesFileResource = PropertiesConfigSourceProvider.propertiesSources("tenant.properties",
        this.getClass().getClassLoader());

var smallryeConfig = new SmallRyeConfigBuilder()
        .withSources(propertiesFileResource)
        .withMapping(BananaConfig.class)
        .build();

return smallryeConfig.getConfigMapping(BananaConfig.class, "banana");

    which does the job.

    Note: