MongoDB and Java

You can find below some hints for initial Java and MongoDB integration

Take a Look at the Requirements

1. MongoDB
2. MongoDB-Java-Driver
3. JDK. If you want use JDK 1.6 or newer, you will get an error like this one: "DBObject cannot be resolved to a type"

Installing Java

yum -y install java-1.7.0-openjdk

yum -y install java-1.7.0-openjdk-devel

Getting MongoDB driver

Compiling Java

javac -d . *.java

java -cp . com/example/mbeans/Main

Define MongoDB Headers in the Code

import com.mongodb.MongoClient;

import com.mongodb.MongoException;

import com.mongodb.WriteConcern;

import com.mongodb.DB;

import com.mongodb.DBCollection;

import com.mongodb.BasicDBObject;

import com.mongodb.DBObject;

import com.mongodb.DBCursor;

import com.mongodb.ServerAddress;

import com.mongodb.*;

Connect to MongoDB

DB _db;

public void init() {

try {

System.out.println("Connecting to mongo...");

MongoClient mongoClient = new MongoClient("127.0.0.1" , 27017);

_db = mongoClient.getDB("display");

System.out.println("Connected to mongo...");

} catch (Exception e) {

System.out.println("Failed Connecting Mongo...");

}

Query the Database (Get the Number of Connections)

CommandResult stats = _db.command("serverStatus");

return Integer.valueOf((((DBObject)(stats.get("connections"))).get("current")).toString());

Bottom Line

Java and MongoDB integration is not too difficult, you just need to do the right thinks right...

Keep Performing,

Moshe Kaplan