ConfigProperty not injecting the value into the field

Question

I am new to quarkus environment. I have a quarkus application where I'm trying to inject the property config using

org.eclipse.microprofile.config.inject.ConfigProperty

Here is the sample code

public class Temp {

    @ConfigProperty(name = "secret.token")
    static String SECRET_KEY;

    public void display() {
        System.out.println(SECRET_KEY);
    }
}

Here is the content of my application.properties

secret.token = ${TOKEN_SECRET:Root}

Here display method is always printing null. The thing is the same property is being injected into the controller/resource endpoint classes properly but not in this class. I also tried using @Inject along with @ConfigProperty but no luck. Any pointers would really help.

Answer 1

The class on which the annotation is used, needs to be a CDI bean.

The easiest way to accomplish that is to annotate the class with @Singleton and use with something like @Inject Temp temp wherever the class is used.

See https://quarkus.io/guides/cdi for an intro to CDI

Answer 2

I had this same problem trying to add a secret key to an encryptor class on tests.

First, the class must have @ApplicationScoped.

Second, for normal scoped beans, you must use getters and setters to that property, or the CDI will not inject it.

See the last comment of 'mkouba' on https://github.com/quarkusio/quarkus/issues/1632 Oct 13,2022

Or read all the thread to understand it.

This is how my class was in the end:

@ApplicationScoped
public class Encryptor {

    private static final String HMAC_SHA_256 = "HmacSHA256";

    @ConfigProperty(name = "APP_SECRET", defaultValue = "fakeDefault")
    String secretKey;

    public String getSecretKey() {
        return secretKey;
    }
    // more code here (used the getter even inside other methods)
}