When the number of dynamic thread pools is empty, there is a CPU idling problem (#803)

hippo4j-example/hippo4j-spring-boot-starter-adapter-spring-cloud-stream-rocketmq-example/src/main/resources/application.properties

@@ -1,6 +1,7 @@
 server.port=8090
 
 spring.profiles.active=dev
+spring.application.name=springcloud-rocketmq-stream-example
 spring.dynamic.thread-pool.server-addr=http://localhost:6691
 spring.dynamic.thread-pool.namespace=prescription
 spring.dynamic.thread-pool.item-id=dynamic-threadpool-example

hippo4j-spring-boot/hippo4j-spring-boot-starter/src/main/java/cn/hippo4j/springboot/starter/core/ClientWorker.java

@@ -18,6 +18,7 @@
 package cn.hippo4j.springboot.starter.core;
 
 import cn.hippo4j.common.model.ThreadPoolParameterInfo;
+import cn.hippo4j.common.toolkit.CollectionUtil;
 import cn.hippo4j.common.toolkit.ContentUtil;
 import cn.hippo4j.common.toolkit.GroupKey;
 import cn.hippo4j.common.toolkit.IdUtil;
@@ -91,7 +92,9 @@ public class ClientWorker {
         this.executor.schedule(() -> {
             try {
                 awaitApplicationComplete.await();
+                if (CollectionUtil.isNotEmpty(cacheMap)) {
                     executorService.execute(new LongPollingRunnable());
+                }
             } catch (Throwable ex) {
                 log.error("Sub check rotate check error.", ex);
             }