title: why the spring gateway filter did not trigger
body: <p>I define a filter in my spring gateway(<code>2.2.8.RELEASE</code>) project like this:</p>
  <pre><code>@Component
  public class LogFilter2 extends AbstractGatewayFilterFactory {
      @Override
      public GatewayFilter apply(Object config) {
          return (exchange,chain) -&gt; {
              System.out.println(&quot;LogFilter2 flitered!!!&quot;);
              return chain.filter(exchange);
          };
      }
  }
  </code></pre>
  <p>then config the filter in <code>application.properties</code> like this:</p>
  <pre><code># dolphin music
  spring.cloud.gateway.discovery.locator.enabled=true
  spring.cloud.gateway.discovery.locator.lower-case-service-id=true
  spring.cloud.gateway.routes[0].id=dolphin-music-service
  # forward by ip:port way
  spring.cloud.gateway.routes[0].uri=http://10.107.64.246:11014
  # forward by service name way
  # spring.cloud.gateway.routes[0].uri=lb://
  spring.cloud.gateway.routes[0].predicates[0]=Path=/music/**
  spring.cloud.gateway.routes[0].filters[0]=LogFilter2
  </code></pre>
  <p>but when I run the project and send a request to the url <code>/music/xxxxxx</code>, the request did not enter the filter.No log <code>LogFilter2 flitered!!!</code> output.what should I do to make the filter works as expect? I also tried many other way,this is the minimal demo:<a href="https://github.com/jiangxiaoqiang/java-learn" rel="nofollow noreferrer">https://github.com/jiangxiaoqiang/java-learn</a>. In this demo, I define different kind of gateway filter, no one work except the global gateway filter. I am struggle with this problem for days.</p>