fix for http://forum.yacy-websuche.de/viewtopic.php?f=6&t=1360&p=9321#p9321

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@5104 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/de/anomic/kelondro/kelondroTree.java

@@ -152,7 +152,16 @@ public class kelondroTree extends kelondroCachedRecords implements kelondroIndex
     }
 
     public boolean has(final byte[] key) {
-        throw new UnsupportedOperationException("has should not be used with kelondroTree.");
+        boolean result;
+        synchronized (writeSearchObj) {
+            try {
+                writeSearchObj.process(key);
+                result = writeSearchObj.found();
+            } catch (final IOException e) {
+                result = false;
+            }
+        }
+        return result;
     }
     
     // Returns the value to which this map maps the specified key.