Java + MongoDB basic example

A simple Java + MongoDB basic example – Following areas are discussed in this blog how to connect, create database, collection and document, save, update, remove, get and display document. Tools and technologies used : MongoDB 2.2.3 MongoDB-Java-Driver 2.10.1 JDK 1.6 Maven 3.0.3 Eclipse 4.2 

import java.net.UnknownHostException;
import java.util.Date;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.MongoClient;
import com.mongodb.MongoException;

/**
 * Java + MongoDB Hello world Example
 *
 */
public class App {
  public static void main(String[] args) {

    try {

 /**** Connect to MongoDB ****/
 // Since 2.10.0, uses MongoClient
 MongoClient mongo = new MongoClient("localhost", 27017);

 /**** Get database ****/
 // if database doesn't exists, MongoDB will create it for you
 DB db = mongo.getDB("testdb");

 /**** Get collection / table from 'testdb' ****/
 // if collection doesn't exists, MongoDB will create it for you
 DBCollection table = db.getCollection("user");

 /**** Insert ****/
 // create a document to store key and value
 BasicDBObject document = new BasicDBObject();
 document.put("name", "java");
 document.put("age", 30);
 document.put("createdDate", new Date());
 table.insert(document);

 /**** Find and display ****/
 BasicDBObject searchQuery = new BasicDBObject();
 searchQuery.put("name", "java");

 DBCursor cursor = table.find(searchQuery);

 while (cursor.hasNext()) {
  System.out.println(cursor.next());
 }

 /**** Update ****/
 // search document where name="java" and update it with new values
 BasicDBObject query = new BasicDBObject();
 query.put("name", "java");

 BasicDBObject newDocument = new BasicDBObject();
 newDocument.put("name", "java-updated");

 BasicDBObject updateObj = new BasicDBObject();
 updateObj.put("$set", newDocument);

 table.update(query, updateObj);

 /**** Find and display ****/
 BasicDBObject searchQuery2
     = new BasicDBObject().append("name", "java-updated");

 DBCursor cursor2 = table.find(searchQuery2);

 while (cursor2.hasNext()) {
  System.out.println(cursor2.next());
 }

 /**** Done ****/
 System.out.println("Done");

    } catch (UnknownHostException e) {
 e.printStackTrace();
    } catch (MongoException e) {
 e.printStackTrace();
    }

  }
}
Output 


{ "_id" : { "$oid" : "51398e6e30044a944cc23e2e"} , "name" : "java" , "age" : 30 , "createdDate" : { "$date" : "2013-03-08T07:08:30.168Z"}}
{ "_id" : { "$oid" : "51398e6e30044a944cc23e2e"} , "age" : 30 , "createdDate" : { "$date" : "2013-03-08T07:08:30.168Z"} , "name" : "java-updated"}
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