Micronaut Endpoint/Controller that reveals the calling thread.

ThreadEndpoint.java

package com.hello.controllerthread;

import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Get;
import io.reactivex.Single;

import java.util.Map;

@Controller("/thread")
public class ThreadEndpoint
{
    static final class ThreadInfo {
        public final String id, name, group;
        
        ThreadInfo() {
            Thread t = Thread.currentThread();
            
            id = String.valueOf(t.getId());
            name = t.getName();
            group = t.getThreadGroup().getName();
        }
    }
    
    @Get("/reactive")
    Single<Map<String, ThreadInfo>> reactiveReturn() {
        var executor = entryOfThread("executor");
        
        return Single.fromCallable(() ->
                Map.ofEntries(executor, entryOfThread("subscriber")));
    }
    
    @Get("/nonreactive")
    Map.Entry<String, ThreadInfo> nonReactive() {
        return entryOfThread("executor");
    }
    
    private static Map.Entry<String, ThreadInfo> entryOfThread(String key) {
        return Map.entry(key, new ThreadInfo());
    }
}