Category Archives: Web Services

Understanding JSON web service with example

In my previous post, I was talking about web service. Now I will take you to details of RESTful service (JSON). Before getting into details of web service, you need to understand about http request types like GET, POST etc. If you don’t understand these request don’t proceed further until you are clear with the concept as these are the building blocks.

GET method: This http request is used to get the data using http protocol.  The basic example would be when you try to open www.google.com than a GET request is sent to google server. Google server in response will be sending html document of Home page to the browser.

POST method: This http request is used to submitting data over Internet. When a user submits user registration details than web browser sends POST method to the server with all the details.

You might want to see how it looks like GET method being fired in your browser. I am using firebug to display the request in below Image.

GET HTTP method

GET HTTP method

Now let us understand JSON. JSON stands for Javascript Object Notification. This is used for  data interchange over the web. It is very easy to implement, easy to read & Interpret as human readable and also it’s machine friendly. Whenever any GET request is sent than server sends data in response in JSON format. JSON format consist of key-value pair. A typical JSON response looks like:

{“Student”:[
{“firstName”:“John”, “lastName”:“Doe”},
{“firstName”:“Jane”, “lastName”:“Doe”},
{“firstName”:“Sam”, “lastName”:“Doe”}
]}

Here firstName, lastName are key  & John, Doe are it’s values. So, Developers will be writing JSON parser within the application which can Interpret JSON response and display the content as and where required.

Introduction to Web Services

Those of you who are new to application development might be confused what does web service means & why it’s important in today’s time. When I started working, I too use to ponder what is it. Name appears to be cool & yes web service technology is really cool. Let’s understand it.

Web service Introduction, SOAP, REST

Web service Introduction

When we develop application aka software than one of the important characteristic which it should posses is robustness. We cannot store all the data in the application itself. You might say why not connect the application with database directly but this reduces robustness & have security risk. Web service becomes a layer between the applications. It becomes a mechanism to transfer data over Internet easily between the systems/devices. For example, lets take an example of flipkart (e-commerce website). It has website, mobile app as channel to sell the products. So, their development team is going to write API which can be re-used on both website as well as on mobile device. This reduces efforts, increases robustness. API will fetch the data for product name, details, price, Inventory etc so if in future they want to try different channel say B2B than existing API’s can be used to build B2B system easily.

There are 2 types of web services commonly used:

  1. RESTFul
  2. SOAP

RESTful aka JSON (Java script object notification) is used majorly as it’s light-weight & easier to implement as compared to  SOAP. SOAP (simple object access protocol) is used in legacy systems, applications which require lot of security etc. I hope this small article was able to convene the concept of web services because if you understand the concept  that it becomes easier to understand further in detail.