Added README.

spring-data-riak/README.md

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+# Spring Data support for Riak
+
+The spring-data-riak module strives to make working with Riak painless by providing
+the developer several different ways to easily access or store data using the Riak
+Key/Value store.
+
+## Recent Changes:
+
+* 12/20/2010: AsyncRiakTemplate and Groovy DSL
+
+### Groovy DSL
+
+One cool new feature just added is a Groovy DSL for data access using SDKV/Riak:
+
+    def riak = new RiakBuilder(riakTemplate)
+    def result = null
+
+    riak.set(bucket: "test", key: "test", qos: [dw: "all"], value: obj, wait: 3000L) {
+
+      completed(when: { v -> v.integer == 12 }) { v, meta ->
+        result = v.test
+      }
+      completed { v -> result = "otherwise" }
+
+      failed { e -> println "failure: $e" }
+
+    }
+
+Some things to note here:
+
+* The Groovy DSL utilizes the new AsyncRiakTemplate, so all closure calls happen
+  asynchronously. To block execution until the operation has completed, provide a non-zero
+  timeout value as the `wait` parameter.
+* Callbacks are defined as either `completed` or `failed` closures. In addition to the
+  closure, you can define a "guard" closure, which is called before the main closure and
+  should return non-null or Boolean `true` if the closure should be executed or null or
+  Boolean `false` if the closure is to be skipped. This functionality is inspired by the
+  use of (guard expression in Erlang case statements)[http://en.wikibooks.org/wiki/Erlang_Programming/guards].