Fix SONAR problems

Change-Id: I5c84f1b0879a9aecef5baeee8fe26601d7bde18e
diff --git a/protocols/xmpp/core/api/src/main/java/org/onosproject/xmpp/core/stream/XmppStreamOpen.java b/protocols/xmpp/core/api/src/main/java/org/onosproject/xmpp/core/stream/XmppStreamOpen.java
index 967296b..4ff8d69 100644
--- a/protocols/xmpp/core/api/src/main/java/org/onosproject/xmpp/core/stream/XmppStreamOpen.java
+++ b/protocols/xmpp/core/api/src/main/java/org/onosproject/xmpp/core/stream/XmppStreamOpen.java
@@ -27,11 +27,16 @@
 import java.io.StringWriter;
 import java.util.List;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * Abstracts XMPP stream open event.
  */
 public class XmppStreamOpen implements XmppStreamEvent {
 
+    private final Logger log = LoggerFactory.getLogger(XmppStreamOpen.class);
+
     public static final String QNAME = "stream";
 
     private Element element;
@@ -54,7 +59,7 @@
             writer.write(Namespace.get("jabber:client"));
             out.write(">");
         } catch (IOException ex) {
-            ex.printStackTrace();
+            log.info("Error writing XML", ex);
         }
         return out.toString();
     }
diff --git a/protocols/xmpp/core/ctl/src/main/java/org/onosproject/xmpp/core/ctl/XmppServer.java b/protocols/xmpp/core/ctl/src/main/java/org/onosproject/xmpp/core/ctl/XmppServer.java
index 42c9b39..3913d64 100644
--- a/protocols/xmpp/core/ctl/src/main/java/org/onosproject/xmpp/core/ctl/XmppServer.java
+++ b/protocols/xmpp/core/ctl/src/main/java/org/onosproject/xmpp/core/ctl/XmppServer.java
@@ -71,7 +71,7 @@
             log.info("Listening for device connections on {}", socketAddress);
 
         } catch (Exception ex) {
-            throw new RuntimeException(ex);
+            throw new IllegalStateException(ex);
         }
     }