ARTEMIS-2610 Improve ActiveMQServer.getConnectionCount()

artemis-server/src/main/java/org/apache/activemq/artemis/core/remoting/server/RemotingService.java

@@ -43,6 +43,17 @@ public interface RemotingService {
 
    Set<RemotingConnection> getConnections();
 
+   /**
+    * @return the number of clients connected to this server.
+    */
+   default int getConnectionCount() {
+      final Set<RemotingConnection> connections = getConnections();
+      return connections == null ? 0 : getConnections().size();
+   }
+
+   /**
+    * @return the number of clients which have connected to this server since it was started.
+    */
    long getTotalConnectionCount();
 
    ReusableLatch getConnectionCountLatch();

artemis-server/src/main/java/org/apache/activemq/artemis/core/remoting/server/impl/RemotingServiceImpl.java

@@ -26,6 +26,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.ServiceLoader;
 import java.util.Set;
+import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
@@ -93,7 +94,7 @@ public class RemotingServiceImpl implements RemotingService, ServerConnectionLif
 
    private final Map<String, Acceptor> acceptors = new HashMap<>();
 
-   private final Map<Object, ConnectionEntry> connections = new ConcurrentHashMap<>();
+   private final ConcurrentMap<Object, ConnectionEntry> connections = new ConcurrentHashMap<>();
 
    private final ReusableLatch connectionCountLatch = new ReusableLatch(0);
 
@@ -500,6 +501,11 @@ public class RemotingServiceImpl implements RemotingService, ServerConnectionLif
       return conns;
    }
 
+   @Override
+   public int getConnectionCount() {
+      return connections.size();
+   }
+
    @Override
    public long getTotalConnectionCount() {
       return totalConnectionCount.get();

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/ActiveMQServerImpl.java

@@ -1677,7 +1677,7 @@ public class ActiveMQServerImpl implements ActiveMQServer {
 
    @Override
    public int getConnectionCount() {
-      return remotingService.getConnections().size();
+      return remotingService.getConnectionCount();
    }
 
    @Override