Refactor ResourceAlertManagerImpl to extract publishAlertEvent method and enhance unit tests for email notifications

Author: Damans227

plugins/resource-alerts/src/main/java/org/apache/cloudstack/resourcealert/ResourceAlertManagerImpl.java

@@ -79,7 +79,7 @@ public class ResourceAlertManagerImpl extends ManagerBase implements ResourceAle
     @Inject ConfigurationDao configDao;
 
     private ScheduledExecutorService executor;
-    private final ExecutorService emailExecutor = Executors.newCachedThreadPool(r -> {
+    ExecutorService emailExecutor = Executors.newCachedThreadPool(r -> {
         Thread t = new Thread(r, "ResourceAlertEmailSender");
         t.setDaemon(true);
         return t;
@@ -274,11 +274,7 @@ private void fireAlert(ResourceAlertRuleVO rule, Long resourceId, double value)
         String subject = buildSubject(rule, resourceId, value);
         String body = buildBody(rule, resourceId, value);
         long dcId = getDataCenterId(rule.getResourceType(), resourceId);
-        try {
-            AlertGenerator.publishAlertOnEventBus("RESOURCE.ALERT", dcId, null, subject, body);
-        } catch (Exception e) {
-            logger.warn("Failed to publish resource alert event: {}", e.getMessage());
-        }
+        publishAlertEvent(dcId, subject, body);
 
         if (rule.isEmail()) {
             sendEmail(subject, body);
@@ -359,6 +355,15 @@ private void sendEmail(String subject, String body) {
         emailExecutor.execute(() -> mailSender.sendMail(mailProps));
     }
 
+    // package-private so tests can stub it without needing a Spring context
+    void publishAlertEvent(long dcId, String subject, String body) {
+        try {
+            AlertGenerator.publishAlertOnEventBus("RESOURCE.ALERT", dcId, null, subject, body);
+        } catch (Exception e) {
+            logger.warn("Failed to publish resource alert event: {}", e.getMessage());
+        }
+    }
+
     @Override
     public String getConfigComponentName() {
         return ResourceAlertManagerImpl.class.getSimpleName();