How to use low-level driver APIs with Spring Data MongoDB

Question

I am using Spring Data MongoDB. But I don't want to map my result to a domain class. Also, I want to access low level MongoAB APIs in few cases. But I want spring to manage the connections pooling etc.

How can i get an instance of com.mongodb.MongoClient to perform low level operations. Here is what I am trying to do :

MongoClient mongoClient = new MongoClient();
DB local = mongoClient.getDB("local");
DBCollection oplog = local.getCollection("oplog.$main");
DBCursor lastCursor = oplog.find().sort(new BasicDBObject("$natural", -1)).limit(1);

Or I simply want a JSON object / DBCursor / DBObject.

Answer 1

you can do it this way

@Autowired MongoDbFactory factory;
DB local = factory.getDB("local");
DBCollection oplog = local.getCollection("oplog.$main");
DBCursor lastCursor = oplog.find().sort(new BasicDBObject("$natural", -1)).limit(1);

Where

MongoDbFactory is an interface provifed by spring-data-mongo that can obtain a        
com.mongodb.DB object and access allthe functionality of a specific MongoDB database   
instance

your configuration file should contain these informations :

<bean id="mongoFactoryBean"
class="org.springframework.data.mongodb.core.MongoFactoryBean">
    <property name="host" value="127.0.0.1"/>
    <property name="port" value="27017"/>
</bean>

<bean id="mongoDbFactory" 
class="org.springframework.data.mongodb.core.SimpleMongoDbFactory">
    <constructor-arg name="mongo" ref="mongoFactoryBean"/>
    <constructor-arg name="databaseName" value="local"/>
</bean>

doing it like that, spring should stay managing your connection pool.