[JENKINS-44608] Don't check for monitor activation if it is disabled

core/src/main/java/jenkins/management/AdministrativeMonitorsDecorator.java

@@ -78,8 +78,7 @@ public class AdministrativeMonitorsDecorator extends PageDecorator {
 
     public Collection<AdministrativeMonitor> getActiveAdministrativeMonitors() {
         Collection<AdministrativeMonitor> active = new ArrayList<>();
-        Collection<AdministrativeMonitor> ams = new ArrayList<>(Jenkins.getInstance().administrativeMonitors);
-        for (AdministrativeMonitor am : ams) {
+        for (AdministrativeMonitor am : Jenkins.getInstance().getActiveAdministrativeMonitors()) {
             if (am instanceof ReverseProxySetupMonitor) {
                 // TODO make reverse proxy monitor work when shown on any URL
                 continue;
@@ -88,9 +87,7 @@ public class AdministrativeMonitorsDecorator extends PageDecorator {
                 // TODO make URI encoding monitor work when shown on any URL
                 continue;
             }
-            if (am.isEnabled() && am.isActivated()) {
-                active.add(am);
-            }
+            active.add(am);
         }
         return active;
     }

core/src/main/java/jenkins/model/Jenkins.java

@@ -288,6 +288,7 @@ import java.util.logging.Level;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import static hudson.Util.*;
 import static hudson.init.InitMilestone.*;
@@ -2172,6 +2173,13 @@ public class Jenkins extends AbstractCIBase implements DirectlyModifiableTopLeve
         return null;
     }
 
+    /**
+     * Returns the enabled and activated administrative monitors.
+     */
+    public List<AdministrativeMonitor> getActiveAdministrativeMonitors() {
+        return administrativeMonitors.stream().filter(m -> m.isEnabled() && m.isActivated()).collect(Collectors.toList());
+    }
+
     public NodeDescriptor getDescriptor() {
         return DescriptorImpl.INSTANCE;
     }

core/src/main/resources/jenkins/model/Jenkins/manage.jelly

@@ -60,10 +60,8 @@ THE SOFTWARE.
   <l:main-panel>
     <h1>${%Manage Jenkins}</h1>
 
-    <j:forEach var="am" items="${app.administrativeMonitors}">
-      <j:if test="${am.isActivated() and am.isEnabled()}">
-        <st:include page="message.jelly" it="${am}" />
-      </j:if>
+    <j:forEach var="am" items="${app.activeAdministrativeMonitors}">
+      <st:include page="message.jelly" it="${am}" />
     </j:forEach>
 
     <st:include page="downgrade.jelly" />