@Indexed
public class DynamicPropertiesEntity {

   private final Map<String,String> properties = new HashMap<String, String>();

   @Field(analyze=Analyze.YES, store=Store.YES)
   @FieldBridge(impl=StringKeyedMapBridge.class)
   public Map<String, String> getProperties() {
      return properties;
   }

   public DynamicPropertiesEntity set(String key, String value) {
      properties.put(key, value);
      return this;
   }