warn message added

redisson/src/main/java/org/redisson/spring/support/RedissonNamespaceHandlerSupport.java

@@ -15,6 +15,8 @@
  */
 package org.redisson.spring.support;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.xml.NamespaceHandlerSupport;
 
 /**
@@ -23,8 +25,12 @@ import org.springframework.beans.factory.xml.NamespaceHandlerSupport;
  */
 public class RedissonNamespaceHandlerSupport extends NamespaceHandlerSupport {
 
+    static final Logger log = LoggerFactory.getLogger(RedissonNamespaceHandlerSupport.class);
+
     @Override
     public void init() {
+        log.error("Spring XML configuration is deprecated and will be removed in future!");
+
         RedissonNamespaceParserSupport helper
                 = new RedissonNamespaceParserSupport();