$ expression in @Client annotation is not resolved when injecting low level http client.

[KrzysztofKowalczyk]

Expression in Client annotation is not resolved and instead treated in whole as a service id.

Steps to Reproduce

Create a bean and inject http client using an expression in Client annotation. Example:

public class LowLevelClient {

    @Inject @Client("${foo.bar}") // <-- this cause problem during injection
    RxHttpClient client;

    public String hello() {
        HttpRequest<?> req = HttpRequest.GET("/");
        return client.exchange(req, String.class).blockingFirst().body();
    }
}

Expected Behaviour

Expression should be resolved and the resolved value should be used as an URI.
Declarative client like the one below works fine.

@Client("${foo.bar}")
public interface DeclarativeClient {

  @Get
  String hello();
}

Actual Behaviour

Expression is not resolved and it is used as service id instead. This is shown by exception:

No available services for ID: ${foo.bar}
io.micronaut.discovery.exceptions.NoAvailableServiceException: No available services for ID: ${foo.bar}
	at io.micronaut.http.client.loadbalance.AbstractRoundRobinLoadBalancer.getNextAvailable(AbstractRoundRobinLoadBalancer.java:51)
	at io.micronaut.core.async.publisher.Publishers$1.doOnNext(Publishers.java:139)
[...]

Environment Information

• Micronaut 1.0.3

Example Application

https://github.com/KrzysztofKowalczyk/micronaut-problems

Test case:
https://github.com/KrzysztofKowalczyk/micronaut-problems/blob/master/src/test/groovy/micronaut/problems/ClientSpec.groovy

Second test is failing

Workaround

1. Use declarative Client
2. Use service id and configure url there

micronaut:
    http:
        services:
            foobar:
                url: 'http://localhost:8080’

3. Setup client manually

public class LowLevelClient {
    RxHttpClient client;

    @PostConstruct
    void initialize() {
        Optional<String> value = applicationContext.getProperty("foo.bar", String.class);
        if (value.isEmpty()) {
            throw new ConfigurationException("foo.bar is not configured");
        }
        try {
            client = RxHttpClient.create(new URL(value.get()));
        } catch (MalformedURLException e) {
            throw new ConfigurationException("Http client could not be created");
        }
    }
[...]