Describe software libraries selected for the Java server backend.

README.md

@@ -69,7 +69,41 @@ TODO
 
 #### Java server backend
 
-TODO
+The application is built using Maven and make uses of Maven Tomcat plugin in
+particular, to ease the development process.
+
+1. Application foundation
+  * _Spring framework core API_  
+    Dependency injection, tests, servlet, etc.
+  * _LogBack_  
+    Modern and powerful logging framework compatible with SLF4J API.
+2. Data persistence  
+  I made my selection with the goal to have a pluggable and extensible solution
+  that makes possible to (almost) transparently switch between DB implementations
+  simply by modifying configuration files.
+  * _Spring Data JPA_  
+    Provides a easy yet powerful way to implement a data access layer, build
+    on top of repositories with automatic default methods.
+  * _EclipseLink_  
+    Full-featured reference implementation of the JPA specification that is
+    compatible with lots of databases (including HSQLDB).
+  * _HSQLDB_  
+    Embedded database that can be run either with a filesystem backend or
+    fully in memory (this mode being used in this application).
+3. Data validation  
+  The application code contains a ``javax.validation``-based solution that
+  validates input data before saving entities.  
+  In this case, the ``geometry`` field of the ``Feature`` entity is validated
+  through a WKT parser.
+  * _javax.validation_
+  * _GeoTools_ (WKT parser)
+4. REST
+  * _Jersey_  
+    Reference implementation of the JAX-RS specification, that easily plugs
+    into _Spring_ dependency injection features via a dedicated module.
+4. Tests
+  * _TestNG_  
+    Unit test framework compatible with both _Spring_ and _Jersey_.
 
 ## **Original assignment description**