Index: src/main/java/org/apache/jackrabbit/oak/jcr/xml/TargetImportHandler.java
===================================================================
--- src/main/java/org/apache/jackrabbit/oak/jcr/xml/TargetImportHandler.java	(revision 1478332)
+++ src/main/java/org/apache/jackrabbit/oak/jcr/xml/TargetImportHandler.java	(working copy)
@@ -22,11 +22,10 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+
 import javax.jcr.RepositoryException;
 import javax.jcr.ValueFactory;
 
-import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.ListMultimap;
 import org.apache.jackrabbit.commons.NamespaceHelper;
 import org.apache.jackrabbit.oak.namepath.LocalNameMapper;
 import org.apache.jackrabbit.oak.namepath.NamePathMapper;
@@ -34,6 +33,12 @@
 import org.xml.sax.SAXException;
 import org.xml.sax.helpers.DefaultHandler;
 
+import com.google.common.base.Function;
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.ListMultimap;
+import com.google.common.collect.Maps;
+
 /**
  * {@code TargetImportHandler} serves as the base class for the concrete
  * classes {@code {@link DocViewImportHandler}} and
@@ -45,12 +50,20 @@
     protected final ValueFactory valueFactory;
     protected final NamespaceHelper helper;
     private final ListMultimap<String, String> documentContext = ArrayListMultimap.create();
-    private Map<String, String> documentPrefixMap = Collections.emptyMap();
+    private final Map<String, String> documentPrefixMap;
 
     protected TargetImportHandler(Importer importer, ValueFactory valueFactory, NamespaceHelper helper) {
         this.importer = importer;
         this.valueFactory = valueFactory;
         this.helper = helper;
+        
+        this.documentPrefixMap = Maps.transformValues(documentContext.asMap(),
+            new Function<Collection<String>, String>() {
+                @Override
+                public String apply(Collection<String> input) {
+                    return Iterables.getLast(input, null);
+                }
+            });
     }
 
     //--------------------------------------------------------< ImportHandler >
@@ -58,7 +71,6 @@
     @Override
     public void startPrefixMapping(String prefix, String uri) throws SAXException {
         documentContext.put(prefix, uri);
-        documentPrefixMap = createCurrentPrefixMap();
     }
 
     @Override
@@ -67,7 +79,6 @@
         if (!uris.isEmpty()) {
             uris.remove(uris.size() - 1);
         }
-        documentPrefixMap = createCurrentPrefixMap();
     }
 
     /**
@@ -123,20 +134,6 @@
         });
     }
 
-    private Map<String, String> createCurrentPrefixMap() {
-        Map<String, String> result = new HashMap<String, String>();
-        Set<Map.Entry<String, Collection<String>>> entries = documentContext.asMap().entrySet();
-        for (Map.Entry<String, Collection<String>> entry : entries) {
-            String key = entry.getKey();
-            List<String> value = (List<String>) entry.getValue();
-            if (value != null && !value.isEmpty()) {
-                result.put(key, value.get(value.size() - 1));
-            }
-        }
-        return result;
-    }
-
-
     protected class NameInfo {
 
         private final String localName;