DATAMONGO-1158 - Add Support for MongoDB Java driver 3.0.

We now support mongo-java-driver version 2.x and 3.0 along with MongoDB Server 2.6.7 and 3.0.0.

Please note that some of the configurations options might no longer be valid when used with version 3 of the MongoDB Java driver. Have a look at the table below so see some of the major differences in using version 2.x or 3.0

                      | 2.x                  | 3.0
----------------------+----------------------+-----------------------------------------------
default WriteConcern  | NONE                 | UNACKNOWLEDGED
----------------------+----------------------+-----------------------------------------------
option for slaveOk    | available            | ignored
----------------------+----------------------+-----------------------------------------------
option for autoConnect| available            | ignored
----------------------+----------------------+-----------------------------------------------
write result checking | available            | ignored (errors are exceptions anyway)
----------------------+----------------------+-----------------------------------------------
rest index cache      | available            | throws UnsupportedOperationException
----------------------+----------------------+-----------------------------------------------
DBRef resolution      | via DBRef.fetch      | via collection.findOne
----------------------+----------------------+-----------------------------------------------
MapReduce Options     | applied              | ignored
----------------------+----------------------+-----------------------------------------------
authentication        | via UserCredentials  | via MongoClient
----------------------+----------------------+-----------------------------------------------
WriteConcernException | not available        | translated to DataIntegretyViolationException
----------------------+----------------------+-----------------------------------------------
executeInSession      | available            | requestStart/requestDone commands ignored.
----------------------+----------------------+-----------------------------------------------
index creation        | via createIndex      | via createIndex
----------------------+----------------------+-----------------------------------------------

We need to soften the exception validation a bit since the message is slightly different when using different storage engines in a MongoDB 3.0 environment.

Added an explicit <mongo-client /> element and <client-options /> to the configuration schema. These elements will replace existing <mongo /> and <options /> elements in a subsequent release. Added credentials attribute to <mongo-client /> which allows to define a set of credentials used for setting up the MongoClient correctly using authentication data. We now reject <mongo-options /> configuration when using MongoDB Java driver generation 3.0 and above.

Original pull request: #273.

src/main/asciidoc/index.adoc

@@ -31,6 +31,7 @@ include::reference/mapping.adoc[]
 include::reference/cross-store.adoc[]
 include::reference/logging.adoc[]
 include::reference/jmx.adoc[]
+include::reference/mongo-3.adoc[]
 :leveloffset: -1
 
 [[appendix]]

src/main/asciidoc/reference/mapping.adoc

@@ -190,7 +190,7 @@ public class Person {
 ----
 ====
 
-IMPORTANT: The `@Id` annotation tells the mapper which property you want to use for the MongoDB `_id` property and the `@Indexed` annotation tells the mapping framework to call `ensureIndex` on that property of your document, making searches faster.
+IMPORTANT: The `@Id` annotation tells the mapper which property you want to use for the MongoDB `_id` property and the `@Indexed` annotation tells the mapping framework to call `createIndex` on that property of your document, making searches faster.
 
 IMPORTANT: Automatic index creation is only done for types annotated with `@Document`.
 

src/main/asciidoc/reference/mongo-3.adoc

@@ -0,0 +1,93 @@
+[[mongo.mongo-3]]
+= MongoDB 3.0 Support
+
+Spring Data MongoDB allows usage of both _mongo-java-driver_ generations 2 and 3 when connecting to a MongoDB 2.6/3.0 server running _MMap.v1_ or a MongoDB server 3.0 using _MMap.v1_ or the _WiredTiger_ storage engine. 
+
+NOTE: Please refer to the driver and database specific documentation for major differences between those.
+ 
+NOTE: Operations that are no longer valid using a 3.x mongo-java-driver have been deprecated within Spring Data and will be removed in a subsequent release.
+
+[[mongodb:mongo-3-configuration]]
+== Using Spring Data MongoDB with MongoDB 3.0
+
+=== Configuration Options
+
+Some of the configuration options have been changed / removed for the _mongo-java-driver_. The following options will be ignored using the generation 3 driver:
+
+ * autoConnectRetry
+ * maxAutoConnectRetryTime
+ * slaveOk
+ 
+Generally it is recommended to use the `<mongo:mongo-client ... />` and `<mongo:client-options ... />` elements instead of `<mongo:mongo ... />` when doing XML based configuration, since those elements will only provide you with attributes valid for the 3 generation java driver.
+
+[source,xml]
+----
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xmlns:mongo="http://www.springframework.org/schema/data/mongo"
+	xsi:schemaLocation="http://www.springframework.org/schema/data/mongo http://www.springframework.org/schema/data/mongo/spring-mongo.xsd
+		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+		
+  <mongo:mongo-client host="127.0.0.1" port="27017">
+    <mongo:client-options write-concern="NORMAL" />
+  </mongo:mongo-client>
+
+</beans>
+----
+
+=== WriteConcern and WriteConcernChecking
+
+The `WriteConcern.NONE`, which had been used as default by Spring Data MongoDB, was removed in 3.0. Therefore in a MongoDB 3 environment the `WriteConcern` will be defaulted to `WriteConcern.UNACKNOWLEGED`. In case `WriteResultChecking.EXCEPTION` is enabled the `WriteConcern` will be altered to `WriteConcern.ACKNOWLEDGED` for write operations, as otherwise errors during execution would not be throw correctly, since simply not raised by the driver. 
+
+=== Authentication
+
+MongoDB Server generation 3 changed the authentication model when connecting to the DB. Therefore some of the configuration options available for authentication are no longer valid. Please use the `MongoClient` specific options for setting credentials via `MongoCredential` to provide authentication data.
+
+[source,java]
+----
+@Configuration
+public class ApplicationContextEventTestsAppConfig extends AbstractMongoConfiguration {
+
+  @Override
+  public String getDatabaseName() {
+    return "database";
+  }
+
+  @Override
+  @Bean
+  public Mongo mongo() throws Exception {
+    return new MongoClient(singletonList(new ServerAddress("127.0.0.1", 27017)),
+      singletonList(MongoCredential.createCredential("name", "db", "pwd".toCharArray())));
+  }
+}
+----
+
+In order to use authentication with XML configuration use the `credentials` attribue on `<mongo-client>`. 
+
+[source,xml]
+----
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xmlns:mongo="http://www.springframework.org/schema/data/mongo"
+	xsi:schemaLocation="http://www.springframework.org/schema/data/mongo http://www.springframework.org/schema/data/mongo/spring-mongo.xsd
+		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+		
+  <mongo:mongo-client credentials="user:password@database" />
+
+</beans>
+----
+
+=== Other things to be aware of
+
+This section covers additional things to keep in mind when using the 3.0 driver.
+
+* `IndexOperations.resetIndexCache()` is no longer supported.
+* Any `MapReduceOptions.extraOption` is silently ignored.
+* `WriteResult` does not longer hold error informations but throws an Exception.
+* `MongoOperations.executeInSession()` no longer calls `requestStart` / `requestDone`.
+* Index name generation has become a driver internal operations, still we use the 2.x schema to generate names.
+* Some Exception messages differ between the generation 2 and 3 servers as well as between _MMap.v1_ and _WiredTiger_ storage engine.
+ 
+

src/main/asciidoc/reference/mongodb.adoc

@@ -1159,7 +1159,7 @@ Before we are actually able to use full text search we have to ensure to set up
 
 [source,javascript]
 ----
-db.foo.ensureIndex(
+db.foo.createIndex(
 {
   title : "text",
   content : "text"