Reporter

If you use a clean architecture in your applications, you may wonder where it is okay to use a log or metric library. Its use should be restricted to the outer layers. A good way to use it in a use case would be to do it through an interface.

Reporter is designed to avoid coding the implementation of that interface and that your only job is to declare methods with meaningful names.

How to use

Just include the dependencies in maven or gradle.

Configuration

Gradle java project

dependencies {
    compileOnly("dev.xoa.reporter:reporter-api:1.0.3")
    annotationProcessor("dev.xoa.reporter:reporter-generator:1.0.3")
}

Gradle kotlin project

plugins {
    kotlin("kapt")
}

dependencies {
    compileOnly("dev.xoa.reporter:reporter-api:1.0.3")
    kapt("dev.xoa.reporter:reporter-generator:1.0.3")
}

Maven java project

<dependences>
    <dependency>
      <groupId>dev.xoa.reporter</groupId>
      <artifactId>reporter-generator</artifactId>
      <version>1.0.3</version>
      <scope>provided</scope>
    </dependency>
</dependences>

Reporter interface

Then annotate your interface as @Reporter. You can use underline characters to mark where put the arguments.

import dev.xoa.reporter.Reporter;

@Reporter
public interface YourReporter {

    void infoHello_Requested(String name);

    void incrementHelloRequestedWithName_(String name);
}

At compiling time the following implementation will be generated:

import org.slf4j.LoggerFactory;
import org.slf4j.Logger;
import org.springframework.stereotype.Component;

import io.micrometer.core.instrument.MeterRegistry;

import io.micrometer.core.instrument.Tag;

@Component
public class YourReporterImpl implements YourReporter {

	private static final Logger log = LoggerFactory.getLogger(ApiReporterImpl.class);

	private final MeterRegistry meterRegistry;

	public ApiReporterImpl(MeterRegistry meterRegistry) {
		this.meterRegistry = meterRegistry;
	}
	
	@Override
	public void infoHello_Requested(java.lang.String name) {
		log.info("hello {} requested", name);
	}

	@Override
	public void incrementHelloRequestedWithName_(java.lang.String name) {
		String code = "hello.requested";
		Iterable<Tag> tags = java.util.Arrays.asList(Tag.of("name", name));
		this.meterRegistry.counter(code, tags).increment(1.0);
	}
}

Use

So, you can use the interface:

public class YourUseCase {

    private final YourReporter reporter;
    
    public YourUseCase(YourReporter reporter) {
        this.reporter = reporter;
    }

    public String invoke(String name) {
        reporter.infoHello_Requested(name);
        reporter.incrementHelloRequestedWithName_(name);

        return "Hello " + name + "!!!";
    }
}

TODO

• What would be the correct package for the implementation?
• Complete tests
• Better documentation
• Log error with exception should not require underscore
• Fails when values are not simple
• Log type must be the interface, not impl