title: Mono subscribe is not executing
body: <p>I have started learning reactive programming using spring boot and when I tried execute the below piece of code from route function, the mono subscribe part of logic is not executing.</p>
  <pre><code>@SpringBootApplication
  public class MonotopayloadApplication {
  
      public static void main(String[] args) {
          SpringApplication.run(MonotopayloadApplication.class, args);
      }
  
      @Bean
      RouterFunction&lt;ServerResponse&gt; videoEndPoint() {
          return route()
                  .path(&quot;/test&quot;, builder -&gt; builder
                          .POST(&quot;&quot;, this::handle)
                  ).build();
      }
  
      private Mono&lt;ServerResponse&gt; handle(ServerRequest serverRequest) {
          serverRequest.bodyToMono(String.class)
                  .subscribe(result -&gt; {
                      try {
                          Thread.sleep(5000);
                      } catch (InterruptedException e) {
                          e.printStackTrace();
                      }
                      System.out.println(&quot;subscribe thread : &quot; + Thread.currentThread().getName());
                  });
          System.out.println(&quot;Thread : &quot; + Thread.currentThread().getName() + &quot; is leaving&quot;);
  
          return Mono.empty();
      }
  }
  </code></pre>
  <p>I do not want to call the block/blockFirst/blockLast(). I understand the main thread is leaving the subscribe thread. Kindly help.</p>