About MongoDB (from wikipedia)
- In case you don't know what it is, then MongoDB (from "humongous") is a free and open-source cross-platform document-oriented database software. Classified as a NoSQL database,
MongoDB avoids the traditional table-based relational
database structure in favor of JSON-like
documents with dynamic schemas (MongoDB
calls the format BSON), making the integration of data in
certain types of applications easier and faster. It provides high performance, high
availability, and easy scalability.
From java developers outlook - If MongoDB is deliberated to persist some or all data in java based application
architecture, then java developers need to write java code in data access layer
of application to perform CRUD and other operations with MongoDB backend using Java MongoDB Driver API
or may be Spring Data MongoDB (just imagine this something like writing JDBC code to exchange
data between JavaEE app and RDBMS). --- On a
separate note, are you aware about the term polyglot persistence describing hybrid approach to persistence by using
different data storage technologies to handle varying data persistence needs!
M101J Course: MongoDB for
Java Developers
Speaking of MongoDB,
recently I got opportunity to attend "M101J: MONGODB FOR JAVA DEVELOPERS" course which is a free
7 weeks online course and expects attendees to spend 6-8 hours per week
as per the designed course agenda. The course delivers everything java
developers need to know for getting started with building a MongoDB-based java
application, which includes basic MongoDB installation, JSON, schema design,
crud operations, indexing, aggregation framework, application engineering and working with MongoDB java language
drivers. The data interaction between Java app and MongoDB is practically
demonstrated by building a java based blogging platform, backed by MongoDB.
Moreover, one will receive a certificate of M101J course completion at the end, if achieves a 65% or above on graded
material.
As a matter of fact, the quality of M101J is elegant
and specially designed for java developers to get started with MongoDB. If you
wish to learn MongoDB or don't have exposure of any of NoSQL database, then I
highly endorse to register and attend this course.
Self-paced Getting Started
with MongoDB
In case you can't
manage to accomplish the M101J course, then you can get started with MongoDB as
below.
Firstly I suggest to
go through MongoDB@TutorialsPoint course to get fair understanding of MongoDB. Don't just read, but also try
practically as you progress.
Once you become
familiar with MongoDB, then I suggest to refer the sample java code snippet
used in the M101J course. For this, you can setup M101J java project and
explore code as below.
- Download / Clone "MongoDB-ForJavaApp/M101J" project to your local machine from GitHub.
- Import "M101J" project in Eclipse. Fix build path errors, such as JRE configuration. This is maven based project, so it would download dependent jar files from internet.
- Ensure MongoD process is running.
- Go to "com.tengen.helloworld" package in "src/main/java" folder of the project. As per "README.md" file, create "hello" collection and insert data. Now see code of "HelloWorldMongoDBStyle.java" and run it; which should connect to "course" db in MongoDB, get data from "course" collection and finally print on console. The other hello world programs in this folder are to demo basic usage of freemarker (templating engine) and spark (micro web framework which allows to setup routes for mapping urls and having embedded Jetty) frameworks, which are used to build frontend templates and controller components of blogging app tutorial. For example - just run "HelloWorldMongoDBSparkFreemarkerStyle.java" program and access "http://localhost:8082" url in the browser, so it would fetch data from MongoDB and show on browser page.
- Go to "com.tengen.crud" package in "src/main/java" folder of the project to explore java code for Mongo crud operations.
- Finally explore sample blogging application.
- How to run it?
- Ensure MongoDB instance "mongodb://localhost" is up and running, otherwise you may need to change default configuration is in BlogController.java.
- Run BlogController.java as java application or using maven command. This would run it on HTTP 8082 port using Spark framework.
- Now you should be able to access it in browser using this URL "http://localhost:8082/" and can play with the blogging application functionality.
- Executive summary of code structure,
- UI components are designed using Freemarker template, which are mapped for URL routing using Spark framework in BlogController.java.
- DAO components has data access layer code implemented using MongoDB driver.
- MongoDB database name is "blog", which contains three collections (1) users (2) sessions (3) posts.
Also Refer
- MongoDB Manual Documentation
- Dzone Refcardz - NoSQL and MongoDB
