Enable checkstyle rule for missing defaults in switch statements

Enabled the checkstyle rule that looks for switch statements that
don't have a default label and fixed the violations that were
found.

Code review results for switch statement default branches

Change-Id: I68716894952835def659b4fcab5b381aaf9ff89e
diff --git a/src/main/java/net/onrc/onos/core/intent/IntentMap.java b/src/main/java/net/onrc/onos/core/intent/IntentMap.java
index 25b98a5..e72cb13 100644
--- a/src/main/java/net/onrc/onos/core/intent/IntentMap.java
+++ b/src/main/java/net/onrc/onos/core/intent/IntentMap.java
@@ -9,6 +9,8 @@
 
 import net.onrc.onos.core.intent.Intent.IntentState;
 import net.onrc.onos.core.intent.runtime.IntentStateList;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @author Toshio Koide (t-koide@onlab.us)
@@ -17,6 +19,7 @@
     private HashSet<ChangedListener> listeners = new HashSet<>();
     private HashMap<String, Intent> intents = new HashMap<>();
     private LinkedList<ChangedEvent> events = new LinkedList<>();
+    private static final Logger log = LoggerFactory.getLogger(IntentMap.class);
 
     public enum ChangedEventType {
         /**
@@ -88,6 +91,9 @@
                 case ERROR:
                     handleErrorOperation(operation);
                     break;
+                default:
+                    log.error("Unknown intent operation {}", operation.operator);
+                    break;
             }
         }
         notifyEvents();
@@ -203,6 +209,9 @@
             case DEL_ACK:
                 // do nothing
                 break;
+            default:
+                log.error("Unknown intent state {}", targetIntent.getState());
+                break;
         }
     }