DATAMONGO-1158 - Add Support for mongo-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.

Pleaes note that some of the configurations options might no longer be valid when used with version 3 of the mongo-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             | defaults WriteConncern to ACKNOWLEGED for EXCEPTION
----------------------+-----------------------+-----------------------------------------------
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
----------------------+-----------------------+-----------------------------------------------

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java

@@ -16,11 +16,13 @@
 package org.springframework.data.mongodb.core;
 
 import static com.mongodb.ReadPreference.*;
+import static org.springframework.data.mongodb.MongoClientVersion.*;
 import static org.springframework.data.mongodb.ReflectiveDbInvoker.*;
 import static org.springframework.data.mongodb.ReflectiveMapReduceInvoker.*;
 import static org.springframework.data.mongodb.ReflectiveWriteResultInvoker.*;
 import static org.springframework.data.mongodb.core.query.Criteria.*;
 import static org.springframework.data.mongodb.core.query.SerializationUtils.*;
+import static org.springframework.util.ObjectUtils.*;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -723,13 +725,22 @@ protected void prepareCollection(DBCollection collection) {
 
 	/**
 	 * Prepare the WriteConcern before any processing is done using it. This allows a convenient way to apply custom
-	 * settings in sub-classes.
+	 * settings in sub-classes. <br />
+	 * In case of using mongo-java-driver version 3 the returned {@link WriteConcern} will be defaulted to
+	 * {@link WriteConcern#ACKNOWLEDGED} when {@link WriteResultChecking} is set to {@link WriteResultChecking#EXCEPTION}.
 	 * 
 	 * @param writeConcern any WriteConcern already configured or null
 	 * @return The prepared WriteConcern or null
 	 */
 	protected WriteConcern prepareWriteConcern(MongoAction mongoAction) {
-		return writeConcernResolver.resolve(mongoAction);
+
+		WriteConcern wc = writeConcernResolver.resolve(mongoAction);
+
+		if (isMongo3Driver() && nullSafeEquals(WriteResultChecking.EXCEPTION, writeResultChecking)
+				&& (wc == null || wc.getW() < 1)) {
+			return WriteConcern.ACKNOWLEDGED;
+		}
+		return wc;
 	}
 
 	protected <T> void doInsert(String collectionName, T objectToSave, MongoWriter<T> writer) {

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/MongoTemplateTests.java

@@ -18,7 +18,6 @@
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 import static org.junit.Assume.*;
-import static org.springframework.data.mongodb.MongoClientVersion.*;
 import static org.springframework.data.mongodb.ReflectiveWriteConcernInvoker.*;
 import static org.springframework.data.mongodb.ReflectiveWriteResultInvoker.*;
 import static org.springframework.data.mongodb.core.query.Criteria.*;
@@ -227,11 +226,7 @@ public void bogusUpdateDoesNotTriggerException() throws Exception {
 	public void throwsExceptionForDuplicateIds() {
 
 		MongoTemplate template = new MongoTemplate(factory);
-		if (isMongo3Driver()) {
-			template.setWriteConcern(WriteConcern.ACKNOWLEDGED);
-		} else {
-			template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
-		}
+		template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
 
 		Person person = new Person(new ObjectId(), "Amol");
 		person.setAge(28);
@@ -254,11 +249,7 @@ public void throwsExceptionForDuplicateIds() {
 	public void throwsExceptionForUpdateWithInvalidPushOperator() {
 
 		MongoTemplate template = new MongoTemplate(factory);
-		if (isMongo3Driver()) {
-			template.setWriteConcern(WriteConcern.ACKNOWLEDGED);
-		} else {
-			template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
-		}
+		template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
 
 		ObjectId id = new ObjectId();
 		Person person = new Person(id, "Amol");
@@ -283,11 +274,7 @@ public void throwsExceptionForUpdateWithInvalidPushOperator() {
 	public void throwsExceptionForIndexViolationIfConfigured() {
 
 		MongoTemplate template = new MongoTemplate(factory);
-		if (isMongo3Driver()) {
-			template.setWriteConcern(WriteConcern.ACKNOWLEDGED);
-		} else {
-			template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
-		}
+		template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
 		template.indexOps(Person.class).ensureIndex(new Index().on("firstName", Direction.DESC).unique());
 
 		Person person = new Person(new ObjectId(), "Amol");
@@ -316,11 +303,7 @@ public void rejectsDuplicateIdInInsertAll() {
 		thrown.expectMessage("E11000 duplicate key error index: database.person.$_id_");
 
 		MongoTemplate template = new MongoTemplate(factory);
-		if (isMongo3Driver()) {
-			template.setWriteConcern(WriteConcern.ACKNOWLEDGED);
-		} else {
-			template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
-		}
+		template.setWriteResultChecking(WriteResultChecking.EXCEPTION);
 
 		ObjectId id = new ObjectId();
 		Person person = new Person(id, "Amol");