Removed Mongo specific id handling from ConfigurationBuilder.

Introduced MongoPersistentProperty that implements handling of fields with certain types and names as id property.

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/mapping/MongoMappingConfigurationBuilder.java

@@ -61,7 +61,8 @@ public class MongoMappingConfigurationBuilder extends BasicMappingConfigurationB
 
   @Override
   public PersistentProperty<?> createPersistentProperty(Field field, PropertyDescriptor descriptor) throws MappingConfigurationException {
-    PersistentProperty<?> property = super.createPersistentProperty(field, descriptor);
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    PersistentProperty<?> property = new MongoPersistentProperty(field.getName(), field.getType(), field, descriptor);
     if (field.isAnnotationPresent(Indexed.class)) {
       Indexed index = field.getAnnotation(Indexed.class);
       String collection = index.collection();
@@ -122,19 +123,6 @@ public class MongoMappingConfigurationBuilder extends BasicMappingConfigurationB
     return super.createAssociation(property);
   }
 
-  @Override
-  protected boolean isIdField(Field field) {
-    if (super.isIdField(field)) {
-      return true;
-    }
-    if (field.getType() == ObjectId.class || field.getType() == BigInteger.class) {
-      if ("id".equals(field.getName()) || "_id".equals(field.getName())) {
-        return true;
-      }
-    }
-    return false;
-  }
-
   protected void ensureIndex(String collection,
                              final String name,
                              final String def,

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/mapping/MongoPersistentProperty.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2011 by the original author(s).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.document.mongodb.mapping;
+
+import java.beans.PropertyDescriptor;
+import java.lang.reflect.Field;
+import java.math.BigInteger;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.bson.types.ObjectId;
+import org.springframework.data.mapping.BasicPersistentProperty;
+
+/**
+ * Mongo specific
+ * {@link org.springframework.data.mapping.model.PersistentProperty}
+ * implementation.
+ * 
+ * @author Oliver Gierke
+ */
+public class MongoPersistentProperty<T> extends BasicPersistentProperty<T> {
+
+  private static final Set<Class<?>> SUPPORTED_ID_TYPES = new HashSet<Class<?>>();
+  private static final Set<String> SUPPORTED_ID_PROPERTY_NAMES = new HashSet<String>();
+
+  static {
+    SUPPORTED_ID_TYPES.add(ObjectId.class);
+    SUPPORTED_ID_TYPES.add(String.class);
+    SUPPORTED_ID_TYPES.add(BigInteger.class);
+
+    SUPPORTED_ID_PROPERTY_NAMES.add("id");
+    SUPPORTED_ID_PROPERTY_NAMES.add("_id");
+  }
+
+  /**
+   * Creates a new {@link MongoPersistentProperty}.
+   * 
+   * @param name
+   * @param type
+   * @param field
+   * @param propertyDescriptor
+   */
+  public MongoPersistentProperty(String name, Class<T> type, Field field,
+      PropertyDescriptor propertyDescriptor) {
+    super(name, type, field, propertyDescriptor);
+  }
+
+  /**
+   * Also considers fields as id that are of supported id type and name.
+   * 
+   * @see #SUPPORTED_ID_PROPERTY_NAMES
+   * @see #SUPPORTED_ID_TYPES
+   */
+  @Override
+  public boolean isIdProperty() {
+    if (super.isIdProperty()) {
+      return true;
+    }
+
+    return SUPPORTED_ID_TYPES.contains(field.getType())
+        && SUPPORTED_ID_PROPERTY_NAMES.contains(field.getName());
+  }
+}