fix(alarm): Listener may not load

* fix

* add log

Author: ungreat

server/odc-core/src/main/java/com/oceanbase/odc/core/alarm/AlarmService.java

@@ -18,11 +18,9 @@
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
-import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.ServiceLoader;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import javax.annotation.Nullable;
 
@@ -33,16 +31,13 @@
 @Slf4j
 class AlarmService {
 
-    private final List<AlarmEventListener> listeners = new ArrayList<>();
+    private final List<AlarmEventListener> listeners = new CopyOnWriteArrayList<>();
 
-    public AlarmService() {
-        ServiceLoader<AlarmEventListener> load = ServiceLoader.load(AlarmEventListener.class);
-        Iterator<AlarmEventListener> iterator = load.iterator();
-        while (iterator.hasNext()) {
-            AlarmEventListener next = iterator.next();
-            log.debug("AlarmEventListener:" + next.getClass().getName() + "have been loaded");
-            listeners.add(next);
-        }
+    public AlarmService() {}
+
+    public void addListener(AlarmEventListener listener) {
+        listeners.add(listener);
+        log.info("Add AlarmEventListener: {}", listener);
     }
 
     public void alarm(String eventName, Map<String, String> eventMessage) {

server/odc-core/src/main/java/com/oceanbase/odc/core/alarm/AlarmUtils.java

@@ -49,6 +49,10 @@ private AlarmUtils() {}
 
     static AlarmService alarmService = new AlarmService();
 
+    public static void registerListener(AlarmEventListener listener) {
+        alarmService.addListener(listener);
+    }
+
     public static void alarm(String eventName, String eventMessage) {
         alarmService.alarm(eventName, eventMessage);
     }

server/odc-server/src/main/java/com/oceanbase/odc/server/OdcServer.java

@@ -78,7 +78,6 @@ public OdcServer(@Qualifier("metadbMigrate") AbstractMetaDBMigrate metadbMigrate
      * @param args
      */
     public static void main(String[] args) {
-        AlarmUtils.alarm(SERVER_RESTART, LocalDateTime.now().toString());
         initEnv();
         System.setProperty("spring.cloud.bootstrap.enabled", "true");
         PluginSpringApplication.run(OdcServer.class, args);