basic implementation ++

basic implementation ++

data-mapper/index.md

@@ -0,0 +1,26 @@
+---
+layout: pattern
+title: Data Mapper
+folder: data-mapper
+permalink: /patterns/dm/
+categories: Persistence Tier
+tags:
+ - Java
+ - Difficulty-Beginner
+---
+
+## Intent
+Object provides an abstract interface to some type of database or
+other persistence mechanism.
+
+![alt text](./etc/dm.png "Data Mapper")
+
+## Applicability
+Use the Data Mapper in any of the following situations
+
+* when you want to consolidate how the data layer is accessed
+* when you want to avoid writing multiple data retrieval/persistence layers
+
+## Credits
+
+* [Data Mapper](http://richard.jp.leguen.ca/tutoring/soen343-f2010/tutorials/implementing-data-mapper/)