Support to obtain all map records from MappingDatabase

Change-Id: Ia4c5932d35c36d8dbd75e8534e52c3e0c5af4256
diff --git a/protocols/lisp/ctl/src/main/java/org/onosproject/lisp/ctl/impl/map/ExpireHashMap.java b/protocols/lisp/ctl/src/main/java/org/onosproject/lisp/ctl/impl/map/ExpireHashMap.java
index 08f7c88..bb9fd04 100644
--- a/protocols/lisp/ctl/src/main/java/org/onosproject/lisp/ctl/impl/map/ExpireHashMap.java
+++ b/protocols/lisp/ctl/src/main/java/org/onosproject/lisp/ctl/impl/map/ExpireHashMap.java
@@ -18,6 +18,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
@@ -157,6 +159,13 @@
     }
 
     @Override
+    public Collection<V> values() {
+        Collection<V> values = Collections.emptyList();
+        map.values().forEach(v -> values.add(v.getValue()));
+        return values;
+    }
+
+    @Override
     public boolean isEmpty() {
         return map.isEmpty();
     }