+++++++ 20160404 begin+++++++
maven环境：
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongodb-driver</artifactId>
<version>3.2.2</version>
</dependency>
+++++++ 20160404 end+++++++
1、当MongoDB没有添加使用auth认证方式的时候：
MongoClientURI uri = new MongoClientURI("mongodb://192.168.100.140:27017/local",
MongoClientOptions.builder().cursorFinalizerEnabled(false));
MongoClient client = new MongoClient(uri);
MongoDatabase db=client.getDatabase("local");
MongoCollection<Document> collection = db.getCollection("system.users");
List<Document> foundDocument = collection.find().into(new ArrayList<Document>());
System.out.println(foundDocument);
2、当MongoDB启动的时候添加--auth参数启动MongoDB（即安全认证模式下）
MongoClient client = null;
ServerAddress serverAddress = new ServerAddress("192.168.100.140",27017);
List<ServerAddress> seeds = new ArrayList<ServerAddress>();
seeds.add(serverAddress);
MongoCredential credentials = MongoCredential.createScramSha1Credential("admin", "admin", "admin".toChar