OkHttpMetricsInterceptor.java

package com.github.gist.hirokazumiyaji;

import java.util.concurrent.TimeUnit;

import io.micrometer.core.instrument.Timer;
import io.micrometer.spring.web.MeterRegistry;
import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.Response;

public final class OkHttpMetricsInterceptor implements Interceptor {

    private final MeterRegistry registry;
    private final OkHttpTagConfigurer tagConfigurer;
    private final String metricsName;

    public OkHttpMetricsInterceptor(MeterRegistry registry, OkHttpTagConfigurer tagConfigurer, String metricsName) {
        this.registry = registry;
        this.tagConfigurer = tagConfigurer;
        this.metricsName = metricsName;
    }

    @Override
    public Response intercept(Interceptor.Chain chain) throws IOException {
        final Request request = chain.request();
        final long startTime = System.nanoTime();
        final Response response = chain.proceed(request);
        final long endTime = System.nanoTime();
        Timer.Builder timerBuilder = registry.timerBuilder(metricsName)
                                             .tags(tagConfigurer.requestTags(request, response));
        timerBuilder.create().record(endTime - startTime, TimeUnit.NANOSECONDS);
        return response;
    }
}

OkHttpTagConfigurer.java

package com.github.gist.hirokazumiyaji;

import io.micrometer.core.instrument.Tag;
import okhttp3.Request;
import okhttp3.Response;

public class OkHttpTagConfigurer {

    public Iterable<Tag> requestTags(Request request, Response response) {
        return asList(method(request), uri(request), status(response));
    }

    public Tag method(Request request) {
        return Tag.of("method", request.method());
    }

    public Tag uri(Request request) {
        return Tag.of("uri", request.url().toString());
    }

    public Tag status(Response response) {
        return Tag.of("status", String.valueOf(response.code()));
    }

}