fix: prom init (#349)

arex-web-api/src/main/java/com/arextest/web/api/service/WebSpringBootServletInitializer.java

@@ -1,20 +1,23 @@
 package com.arextest.web.api.service;
 
 import com.arextest.common.metrics.PrometheusConfiguration;
-import javax.annotation.PostConstruct;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
 import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+import org.springframework.context.ApplicationListener;
 import org.springframework.scheduling.annotation.EnableAsync;
 
 @Slf4j
 @EnableAsync
 // @EnableSchedulerLock(defaultLockAtMostFor = "PT30S")
 @SpringBootApplication(scanBasePackages = "com.arextest.web")
-public class WebSpringBootServletInitializer extends SpringBootServletInitializer {
+public class WebSpringBootServletInitializer
+    extends SpringBootServletInitializer
+    implements ApplicationListener<ApplicationReadyEvent> {
 
   @Value("${arex.prometheus.port}")
   String prometheusPort;
@@ -28,8 +31,8 @@ protected SpringApplicationBuilder configure(SpringApplicationBuilder applicatio
     return application.sources(WebSpringBootServletInitializer.class);
   }
 
-  @PostConstruct
-  public void init() {
+  @Override
+  public void onApplicationEvent(ApplicationReadyEvent event) {
     PrometheusConfiguration.initMetrics(prometheusPort);
   }
 }