[improve][client] Add log when can't add message to the container (ap…

…ache#21924)

pulsar-client/src/main/java/org/apache/pulsar/client/impl/MessagesImpl.java

@@ -22,11 +22,13 @@
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import lombok.extern.slf4j.Slf4j;
 import net.jcip.annotations.NotThreadSafe;
 import org.apache.pulsar.client.api.Message;
 import org.apache.pulsar.client.api.Messages;
 
 @NotThreadSafe
+@Slf4j
 public class MessagesImpl<T> implements Messages<T> {
 
     private final List<Message<T>> messageList;
@@ -49,10 +51,14 @@ protected boolean canAdd(Message<T> message) {
             return true;
         }
         if (maxNumberOfMessages > 0 && currentNumberOfMessages + 1 > maxNumberOfMessages) {
+            log.warn("can't add message to the container, has exceeded the maxNumberOfMessages : {} ",
+                    maxNumberOfMessages);
             return false;
         }
 
         if (maxSizeOfMessages > 0 && currentSizeOfMessages + message.size() > maxSizeOfMessages) {
+            log.warn("can't add message to the container, has exceeded the maxSizeOfMessages : {} ",
+                    maxSizeOfMessages);
             return false;
         }