Author Archives: Ajitesh Kumar

Ajitesh Kumar

I have been recently working in the area of Data analytics including Data Science and Machine Learning / Deep Learning. I am also passionate about different technologies including programming languages such as Java/JEE, Javascript, Python, R, Julia, etc, and technologies such as Blockchain, mobile computing, cloud-native technologies, application security, cloud computing platforms, big data, etc. For latest updates and blogs, follow us on Twitter. I would love to connect with you on Linkedin. Check out my latest book titled as First Principles Thinking: Building winning products using first principles thinking. Check out my other blog, Revive-n-Thrive.com

AngularJS – How to Create & Use Custom Service

angularjs

This article demonstrates how one could create custom services in AngularJS and use them within controllers or other services using dependency injection. In this article, the service demonstrated is Calculator service with just one API named as “calculate”. The API takes two numbers and operation type and calculate the result appropriately. The demo could be found on this page, http://hello-angularjs.appspot.com/angularjs-create-custom-services Following are three key steps in creating using custom services: Create the code for service (take a look at example below showing Calculator class with a constructor, Calculator() Register the recipe or method to inject the service. Injector service uses this to inject the service Inject the new custom service in …

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Posted in Javascript, UI. Tagged with .

AngularJS – Post Data with ngResource, RESTful APIs and Spring MVC

angularjs restful api

  The article presents concepts and some take-away code samples for developers wanting to POST data to RESTFul APIs using ngResource ($resource) service with SpringMVC on server side. The demo for this example could be found on this page, http://hello-angularjs.appspot.com/angularjs-restful-apis-post-method-code-example.   The primary reason why I loved this approach rather than using $http service is the fact that using ngResource allows you to have abstraction such as a $resource class & its instance on which you have action methods to interact with RESTful APIs. It makes it quite easier to work with RESTful integration. On $resource class object, one could directly call action methods such as get, save. However, on …

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Posted in Java, Javascript, UI. Tagged with , .

Function Point Analysis Tool with AngularJS

Function Point Analysis Tool

The article introduces the function point analysis tool that was created using AngularJS and Bootstrap frameworks. The tool can be accessed at http://function-point-analysis.appspot.com/. Following are some of the Key features of AngularJS that have been demonstrated as part of this tool: Two-way data binding; As the functions are added, the model value such as total function points count changes, and thus view is updated to reflect the new count. Templates used to display inputs in the table displaying functions and its counts Directives such as ng-repeat (adding a table row), ng-show Scope object used as a bridge between view and the controller Form elements such as select, input[number]. Form element …

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Posted in Javascript, Tools. Tagged with .

EmberJS Bootstrap Hello World UI Template

The article is a placeholder for Hello World code for EmberJS with Bootstrap. Those who want to get started with EmberJS can just copy and paste the code in an html file and get started. Among the scripts, you would also find the Bootstrap script and CSS files. Following are, however, some of the observations to be noted: Dependency on JQuery: The primary reason for dependency on JQuery as cited by the Ember code developer in this page is DOM manipulation. Dependency on Handlebars template: This is the templating engine used by EmberJS. EmberJS App Initialization: One needs to an Ember app initiated using the code such as “var app …

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Posted in Javascript, UI. Tagged with , .

AngularJS – Consume RESTful APIs with ngResource or $http

angularjs restful api

  The article presents concepts and code samples on how to consume RESTful APIs with help of AngularJS $resource or $http service. The server side code is written on top of Spring MVC framework. Please feel free to point out suggestions on this blog.Following are key techniques using which one could consumer RESTful APIs Use low-level $http service to retrieve data using GET method. The demo could be found on this page Use $resource service to retrieve data using GET or QUERY action method. The demo could be found on this page   RESTful APIs with Low-level $http Service One could directly use low-level $http service to consumer RESTful APIs …

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Posted in Java, Javascript, UI. Tagged with , , , .

Unit Testing with JUnit & Mockito – Code Examples

unit testing

The article presents quick code example for doing unit testing with JUnit & Mockito mocking framework. It also represents unit testing naming convention where features text is used for naming the test methods thereby representing test class as alternate documentation for the class under test. Following is done while defining Mock member variables Use @Mock annotation ahead of member variable definitions Following are steps done in the setup method: Initialize the mock using MockitoAnnotations.initMocks(this); Object of class under test is initialized with the mock objects Following steps are used in each of the unit test methods: Create/Initialize required objects for working with mocks and methods under test Set the mock …

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Posted in Unit Testing. Tagged with , .

7 Popular Unit Test Naming Conventions

unit-testing

The article presents a compiled list of unit tests naming strategy that one could follow for naming their unit tests. The article is intended to be a quick reference instead of going through multiple great pages such as following. That said, to know greater details, please feel free access one of these pages listed below and know for yourself. Naming Standards for Unit Tests Naming Unit Tests Responsibly What are some popular naming conventions for unit tests? Unit Tests Naming Best Practices GivenWhenThen Technique Following are 7 popular unit tests naming conventions that are found to be used by majority of developers and compiled from above pages: MethodName_StateUnderTest_ExpectedBehavior: There are …

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Posted in Unit Testing. Tagged with .

What is Difference Between Select and Datalist?

The article represents the key difference between Select and Datalist and emphasize on related best practices. Following are key differences Select is an form input type while Datalist isn’t Select input element presents options for the users from which they need to select one of them. On the otherhand, Datalist presents a list of suggested values to the associated input form (text) field and users are free to select one of those suggested values or type in their own value. With Select, users may have to scan a long list for selecting one of the values, while with Datalist, the values are provided as hints and users ain’t bound to …

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Posted in UI, Web. Tagged with .

AngularJS & Bootstrap Hello World UI Template

angularjs bootstrap

The article is a placeholder for the copy & paste code for AngularJS and Bootstrap. If one wants to quickly get started with AngularJS and Bootstrap, one may want to bookmark this page. Points to pay attention: AngularJS script referenced from Google hosted libraries Bootstrap scripts and CSS files from bootstrapcdn   <!DOCTYPE html> <html ng-app=”helloApp”> <head> <title>HelloWorld</title> <link rel=”stylesheet” href=”//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css”> <script src=”//ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js”></script> <script src=”//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js”></script> <script> var helloApp = angular.module( “helloApp”, [] ); helloApp.controller( “HelloCtrl”, [ ‘$scope’, function($scope) { $scope.name = “ajitesh shukla”; }]); </script> </head> <body ng-controller=”HelloCtrl”> <div class=”page-header”> <h1>Hello World Sample Program</h1> </div> <div> <form class=”form-horizontal” role=”form”> <div class=”form-group”> <label class=”col-md-2 control-label”>Type Your Name</label> <div class=”col-md-4″> <input type=”text” …

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Posted in Javascript, UI. Tagged with , .

7 Reasons Why One Should Try Chrome Dev Editor (CDE)

CDE - Chrome Dev Editor

The article presents information on Chrome Dev Editor which was made available to developers in Google IO 2014 event. I played with it and checked various different capabilities. If you think I missed on one or more cool features, please feel free to shout. Also, created a sample AngularJS Hello World program. Following picture represents the following: Ability to clone GIT ptoject Ability to create javascript web apps. Shown is AngularJS helloworld app. Well, frankly speaking, to work with Javascript Web Apps, it is same like any other text editor. However, it brings following benefits to the table which makes it very attractive and WORTH A SPIN: IDE Features: With …

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Posted in Tools, Web. Tagged with , .

AngularJS – How to Post JSON Data using AJAX & SpringMVC

The article presents code samples that one could use to quickly get started with posting JSON data using AngularJS  $http service while working with SpringMVC web application. The demo for the code below could be found on this page, http://hello-angularjs.appspot.com/angularjs-http-service-ajax-post-json-data-code-example.  Earlier, I posted this article where one could post the html data (text/html) using AJAX & SpringMVC. Following are key steps: Create SpringMVC Controller methods and a POJO Create AngularJS Controller Method Create View   SpringMVC Controller methods and a POJO Following are key steps: Create a controller method to access the page consisting of UI that will be posting using AJAX Create a controller method that shall be receiving the …

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Posted in Java, Javascript. Tagged with , , , .

AngularJS & SpringMVC – How to Fix 415 Unsupported Media Type Error

  The article presents tips on how to fix 415 Unsupported Media Type error while working with AngularJS & SpringMVC web application when one tries to POST JSON data using $http service. The sole reason I wanted to write this blog is to help many of my friends who are most likely to hit this one when they work on posting JSON data to SpringMVC web controller using $http service. Possible scenarios: Most likely, you might not have included Jackson libraries in the classpath. Thus, go to http://wiki.fasterxml.com/JacksonDownload and download all the jar files. Alternatively, get slightly back-dated version of all of the libraries in one jar file from http://www.java2s.com/Code/Jar/j/Downloadjacksonall199jar.htm. …

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Posted in Java, Javascript. Tagged with , , , .

AngularJS – How to POST Data using AJAX & Spring MVC – Part 1

The article presents the code example that one may use to post data to server using AngularJS $http service, while working with Spring MVC web application. The same is demonstrated in the following page: http://hello-angularjs.appspot.com/angularjs-http-service-ajax-post-code-example. This article is first in the series of articles on different techniques that could be used to POST different formats of data to the server when working with AngularJS and Spring MVC. In this article, the code samples demonstrate how to post plain HTML text data (text/html) format to the server. Following are key steps: Create Spring MVC web controllers methods Create AngularJS controller method using $http service to post data Create view to receive input …

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Posted in Java, Javascript. Tagged with , , , .

AngularJS – How to Get Data from AJAX & Spring MVC

  The article presents steps one need to code in order to get data from server using XMLHttpRequest (XHR) while working with Spring MVC Java web application. Watch the demo and code samples at http://hello-angularjs.appspot.com/angularjs-http-service-ajax-get-code-example. Following are key steps: Write two methods in Spring MVC controller, one to load the page and other to serve AJAX request Write AngularJS code to get the data (model) in the controller method using $http  Write the view to display the data   Spring MVC Controller Methods Following are two methods one need to write in the Spring MVC Controller: Method below serves the page, views/httpservice_get.jsp when accessed using the following URL: http://hello-angularjs.appspot.com/angularjs-http-service-ajax-get-code-example. Try …

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Posted in Java, Javascript. Tagged with , , , .

OWASP Broken Authentication and Session Management Example

The article presents an example on one of the top OWASP vulnerability related with authentication and session management. This is termed as “Broken Authentication and Session Management”. To know more about this vulnerability and related details, visit OWASP page for broken authentication and session management.   I was surfing a website, http://www.99acres.com, few days back and tried to retrieve my password using “Forgot Password” page. As I entered my username, I was amazed to see my email address shown there. I, then, tried another name such as “karthik” and following was the message:“An email has been sent to karthiksundaram@gmail.com. Please click on the link provided in the email to create …

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Posted in Application Security. Tagged with .

AngularJS Coding Best Practices

angularjs

The article lists down some of the best practices that would be useful for developers while they are coding with AngularJS. These are out of my own experiences while working on AngularJS and do not warranty the entire list. I am sure there can be more to this list and thus, request my readers to suggest/comment such that they could be added to the list below. Found some of the following pages which presents a set of good practices you would want to refer. Thanks to the readers for the valuable contribution. AngularJS Style Guide App Structure Best practices   Initialization One should try and place the <script> tag including …

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Posted in Javascript. Tagged with , .