REST services REST stand for REpresentational State Transfer. It is an architectural style for developing web services. It is primarily used to build web services that are lightweight, maintainable , and scalable. REST is not depend on any protocol , but almost every RESTful service uses HTTP as its underlying protocol. Service architects and developers want this service to be easy to implement, maintainable, extensible, and scalable. What are the features of RESTful services?? Representations Messages URIs Uniform interface Stateless Links between resources Caching What is representation?? Representation describe how resources get manipulated. Once we have identified our resources, the next thing we need is to find a way to represent these resources in our system. We can use any format for representing the resources, REST does not put a restriction on the format of a representation. Eg: AJAX calls or JSON can be used t...
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MVC & MVVC What is MVC? MVC is software architecture design pattern. MVC stands for Model , View and Controller , it is a server side design pattern . MVC pattern is used by well-known frameworks such as Ruby on Rails, Apple ios Development, ASP.NET MVC, etc . It has 3 main component. Model. Controller Views It like as a triangle where all part can communicate with each other. Model Model represent the shape of the data and business logic and also it defines the business rules for data. It contain the pure application data. In J2EE javabean provide Model. View View display data using model to the user. It knows how to access the model’s data but it does not know what this data means. It is script-based templating systems like JSP, ASP, PHP and very easy to integrate with AJAX technology. In J2EE JSP5 provide view. Controller Controllers are responsible for controlling the flow o...
Introduction to NodeJS NodeJS is an open-source,cross-platform, run-time environment for sever-side and networking applications. It is not a JavaScript framework. NodeJS was developed by Ryan Dahl in 2009 on Chrome's V8 JavaScript Engine. It is written using C++ language but uses JavaScript as an interpretive language for server-client request/response processing. NodeJS runs stand-alone JavaScript programs. NodeJS is an asynchronous language .It is lightweight and efficient because of it's event-driven ,non-blocking I/O nature. NodeJS runs on various platforms(windows ,linux , unix , mac , OS X ,). Ideal for data-intensive real-time applications that run across distributed devices. Not the best platform for CPU intensive heavy computational applications. It is capable of handling a huge number of simultaneous connections with high throughput .NodeJS is single threaded. It not create new thread for each connection. Where can be...
What is SOLID principle?? SOLID principles are the design principles that enable us manage most of the software design problem. The terms SOLID is an acronym for five design principles intended to make software designs more understandable , flexible and maintainable The principles are subset of many principles promoted by Robert C . Martin. Why we use SOLID principles in our program?? To achieve reduction in complexity of code. To increase readability, extensibility and maintenance. To reduce error and implement reusability. To achieve better testability. To reduce tight coupling. SOLID acronym S : Single responsibility principle O :Open closed principle L :Liskov substitution principle I :Interface segregation principle D :Dependency inversion principle Single responsibility principle. “A class ...
NoSQL NoSQL databases doesn’t following the relational model , these database works well with today’s interactive development sprints and with cloud computing. These are relation less databases and also more scalable and provide superior performance. NoSQL databases are mainly divided into 4 parts. Key value based database. Store data as key value pair. Eg: redis , memcachedDB , Riak Column based database. Store data in column families. These type of databases are used to storing very large number of record with very large number of information. Eg:Cassandra , HBase Document based database. Store data as document [JSON , BSON , XML] in maps or collection. Complex and arbitrary structure can from a document , these document can be stored using these database. Eg:MongoDB Graph based database. Store data with node and edges connecting each othe...
JavaScript JavaScript is fun and powerful programming language for front end web developing. JavaScript is used most of the popular web applications. Eg : google Map , Gmail , PayPal , LinkedIn …… etc. JavaScript Variable Type JavaScript is loosely type language. In variable declaration we don’t need to define any datatype like integer, string , Boolean. We can declare all type of variable not only integer, Boolean , string but also objects just using ‘var’ or ‘let’ or ‘const’ keywords. Later we’ll discuss about different between these above mentioned keyword. But commonly we use var keyword to declare variable. Variable declaration When declare a variable without initializing a value then it will automatically take undefined or null value. And also we can define multiple variable with same var keyword. Variable naming concerns. JavaScript is case – sensitive. eg : Age , age are two different variable. We can’...