The Core MongoDB Operations with Native Java Driver

MongoDB provides driver and client library support for many languages. Today we will see how operations made in the previous article through the console will be performed in a Java application by using the library provided for Java language. I used the following tools and technologies in application.

• MongoDB version 2.4.1
• MongoDB Java Driver version 2.11.1
• JDK version 1.7 ( also can be used smoothly with 1.6)
• Maven 3.0.4

1. MongoDB Dependencies for Project

<dependency>
  <groupId>org.mongodb</groupId>
  <artifactId>mongo-java-driver</artifactId>
  <version>2.11.1</version>
</dependency>

2. Choosing Connection, Database and Collection with MongoDB

MongoClient mongoClient = new MongoClient( "localhost" , 27017 ); 
DB db  = mongoClient.getDB("kodcu"); 
DBCollection collection  = db.getCollection("articles");

In fact, the MongoClient example represents a connection pool for the database. The call getDB("kodcu") that is done through the client instance is similar to the "use dbName" call in the console. The method checks whether there is a database that has the same name with the parameter value. The database is selected if it exists, if not, a new one is created. A similar situation applies to the db.getCollection("articles") call. If there is not a collection with that name, it is created with the first insert. 3. The Process of Adding Records

insertRecord(new String[] {"Articles"}, 
                         "Lean Kanban Workshop", 
                         "Kanban system is an impressive approach in the field of software management for the last 10 years.", 
                         new Date(), 
                         "Altug Bilgin Altintas", 
                         new String[] {null}, 
                         collection);

public static void insertRecord(String[] category, String title, String content,
                                    Date date, String author, String[] tags, DBCollection collection){
        
        BasicDBObject document = new BasicDBObject("category", category)
                                .append("title", title)
                                .append("content", content)
                                .append("date", date)
                                .append("author", author)
                                .append("tags", tags);
        
        collection.insert(document);
        
        System.out.println("Added record: " + document);
        
}

4. The Process of Updating Records

updateRecord("title", "Lean Kanban Workshop", "tags", new String[]{"lean", "kanban", "training"}, collection);

public static void updateRecord(String findField, String findFieldNewValue, String updatedField, String[] updatedFieldNewValue, DBCollection collection){
        
        BasicDBObject query = new BasicDBObject();
	query.put(findField, findFieldNewValue);
        
	BasicDBObject findDocument = new BasicDBObject();
	findDocument.put(updatedField, updatedFieldNewValue);
 
	BasicDBObject updatedDocument = new BasicDBObject();
	updatedDocument.put("$set", findDocument);
 
	collection.update(query, updatedDocument);       
        System.out.println("Kayit guncellendi: " + updatedDocument);
    
}

5. Finding Records by Field Query, Using Regex Query

DBCursor cursor = findRecord("author", "Altug Bilgin Altintas", collection);

while (cursor.hasNext()) {
   System.out.println("Found records: " + cursor.next());
}

executeRegexQuery("content", "Backbone.*JavaScript", collection);

public static DBCursor findRecord(String field, String value, DBCollection collection){
        
        BasicDBObject query = new BasicDBObject();
	query.put(field, value);
        DBCursor dBCursor = collection.find(query);
        
        return dBCursor;
}

public static void executeRegexQuery(String field, String value, DBCollection collection){
        
        BasicDBObject query = new BasicDBObject();
        query.put(field, new BasicDBObject("$regex", "Backbone.*JavaScript").append("$options", "i"));
        DBCursor cursor = collection.find(query);
        
        System.out.println("***************** Regex Query *****************");
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
        System.out.println("***************** Regex Query *****************");
        
}

6. To List All Records

findAllRecords(collection);

public static void findAllRecords(DBCollection collection){
        
        System.out.println("***************** List all records *****************");
        DBCursor cursor = collection.find();
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
        System.out.println("***************** List all records *****************");
}

7. Deleting a Collection

dropCollection(collection);

public static void dropCollection(DBCollection collection){
        
        collection.drop();
        System.out.println("Collection is initialized");
}

Output produced by the application:

Collection is initialized Eklenen kayit: { "category" : [ "Articles"] , "title" : "Lean Kanban Workshop" , "content" : "Kanban system is an impressive approach in the field of software management for the last 10 years." , "date" : { "$date" : "2013-04-22T09:58:45.155Z"} , "author" : "Altug Bilgin Altintas" , "tags" : [  null ] , "_id" : { "$oid" : "517509d530049e9dccd4ffb0"}} Added record: { "category" : [ "Articles"] , "title" : "Take the reins with Backbone.js! ? Free Webiner" , "content" : "Backbone.js is a JavaScript library that helps your complicated Javascript code to be more structured and offers an environment in which development  is more pleasant." , "date" : { "$date" : "2013-04-22T09:58:45.194Z"} , "author" : "Kodcu.Com" , "tags" : [  null ] , "_id" : { "$oid" : "517509d530049e9dccd4ffb1"}} Added record: { "category" : [ "Java" , "Tutorial" , "Articles" , "Software"] , "title" : "Data Indexing with Java to Apache Solr" , "content" : " Hi all, I mentioned in my previous article the installation and configuration of Apache Solr, data indexing from command line to Solr and making query operations through this data." , "date" : { "$date" : "2013-04-22T09:58:45.197Z"} , "author" : "Cuneyt Yesilkaya" , "tags" : [ "java" , "data indexing with java to solr" , "solr" , "solrj"] , "_id" : { "$oid" : "517509d530049e9dccd4ffb2"}} Record is updated: { "$set" : { "tags" : [ "lean" , "kanban" , "training"]}} Found records: { "_id" : { "$oid" : "517509d530049e9dccd4ffb0"} , "author" : "Altug Bilgin Altintas" , "category" : [ "Articles"] , "content" : "Kanban system is an impressive approach in the field of software management for the last 10 years." , "date" : { "$date" : "2013-04-22T09:58:45.155Z"} , "tags" : [ "lean" , "kanban" , "training"] , "title" : "Lean Kanban Workshop"} ***************** Regex Query ***************** { "_id" : { "$oid" : "517509d530049e9dccd4ffb1"} , "category" : [ "Articles"] , "title" : "Take the reins with Backbone.js! ? Free Webiner" , "content" : "Backbone.js is a JavaScript library that helps your complicated Javascript code to be more structured and offers an environment in which development  is more pleasant." , "date" : { "$date" : "2013-04-22T09:58:45.194Z"} , "author" : "Kodcu.Com" , "tags" : [  null ]} ***************** Regex Query ***************** ***************** List all records ***************** { "_id" : { "$oid" : "517509d530049e9dccd4ffb1"} , "category" : [ "Articles"] , "title" : "Take the reins with Backbone.js! ? Free Webiner" , "content" : "Backbone.js is a JavaScript library that helps your complicated Javascript code to be more structured and offers an environment in which development  is more pleasant." , "date" : { "$date" : "2013-04-22T09:58:45.194Z"} , "author" : "Kodcu.Com" , "tags" : [  null ]} { "_id" : { "$oid" : "517509d530049e9dccd4ffb2"} , "category" : [ "Java" , "Tutorial" , "Articles" , "Software"] , "title" : "Data Indexing with Java to Apache Solr" , "content" : "Hi all, I mentioned in my previous article the installation and configuration of Apache Solr, data indexing from command line to Solr and making query operations through this data." , "date" : { "$date" : "2013-04-22T09:58:45.197Z"} , "author" : "Cuneyt Yesilkaya" , "tags" : [ "java" , "data indexing with java to solr" , "solr" , "solrj"]} { "_id" : { "$oid" : "517509d530049e9dccd4ffb0"} , "author" : "Altug Bilgin Altintas" , "category" : [ "Articles"] , "content" : "Kanban system is an impressive approach in the field of software management for the last 10 years " , "date" : { "$date" : "2013-04-22T09:58:45.155Z"} , "tags" : [ "lean" , "kanban" , "training"] , "title" : "Lean Kanban Workshop"} ***************** List all records *****************

Real content above and the application, can be accessed at The Core MongoDB Operations with Native Java Driver