Sunday, June 16, 2019

Python - Read and write a text file

After coding in Java for nearly 10 years, lately i started learning Python programming and let me tell you it quickly grabbed my interest. So here is the first code for reading and writing a text file using Python. More codes will come along.

read_write_file.py

Saturday, June 1, 2019

Example with React, Redux and Axios API

In previous article we have seen a simple react with redux example. In this article we will add Axios api to it. Axios is used for Promise based HTTP client for the browser and node.js. To know more about axios package, click here.

In this example we will get input name from user and hit a hello world rest endpoint. For running this example you may need to install below packages -
  • redux
  • react-redux
  • axios
  • redux-thunk


App.js

Sunday, March 31, 2019

Simple React + Redux example

In the previous article we have seen Spring boot with react example. In this example we will see how to configure React with Redux. Now what is all this fuss about Redux?


In simple term Redux is used to manage state of your application. As your application starts growing it gets difficult to manage state of your application. This is when Redux comes to help you.

Redux data flow



Lets see a simple counter example. Assuming npm is already installed in your machine. If not, install npm.

Saturday, March 23, 2019

Spring Boot + ReactJS hello world example

Spring Boot is designed to get you up and running as quickly as possible, with minimal upfront configuration of Spring. To know more about spring boot, click here.

ReactJS is a JavaScript library used for building user interfaces. To know more about react, click here.

In this example spring boot will exposed our business logic using rest endpoints and reactjs is used as frontend user interface. Point here to be noted is unlike a traditional web application where java codes + web code (HTML + javascript + css) are residing in same project here spring boot and reactjs will be in different project. The main advantage of this type of setup is to have a loose coupling between your UI and business logic. Tomorrow if you feel to replace reactjs with anjularjs or vuejs you can very well do it without touching business logic.

Step 1 -
Create a spring boot application, click here for more details.

pom.xml


Monday, January 14, 2019

Hello World Parameterized Junit Test

In this article we will see how to build a Parameterized Junit Test.

Parameterized tests was introduced with JUnit 4. Basic concept of Parameterized tests is to run the same test over and over again using different inputs.

There are 4 steps involve in this -

  • Annotate the test class with @RunWith(Parameterized.class)
  • Create a public static method annotated with @Parameterized.Parameters that returns a Collection of Objects as test data set
  • Create a public constructor that takes input as a single data item from step 2
  • Create an instance variable for each item of test data


Lets see the example -

Created a maven project as shown below -


pom.xml

HelloWorld.java

HelloWorldTest.java