Wednesday, December 20, 2017

SendGrid Email API integration with Spring Boot REST Application

SendGrid is a popular cloud-based email delivery service. A few months ago, I had an opportunity to work with this technology along with Spring Boot application to send email to subscribers. Today I am going to develop a very simple Spring Boot REST application to integrate SendGrid email API to send an email to a valid email address.

Sunday, December 17, 2017

Breadth First Search(BFS) In Java

BFS or Breadth First Search is a very well-known graph traversal algorithm. The following java program performs this algorithm using adjacency list representation of graphs. Graphs may contain a cycle. To avoid processing a node twice, we used a Boolean array, name visited.

Friday, December 15, 2017

Generate unique permutation in Java

We already saw how to generate all possible permutation in java. Today we will modify our algorithm to remove duplicate entries to keep only unique permutation.

For an example, if the given string is: 112, our program will generate:

112
121
211

Spring Boot REST API - Convert English Number into Words

Spring is one of the most popular Java EE application framework. Today we will develop a very simple Spring Boot REST API which receives a number as a request and in response, we will get the corresponding English words.

Please note that, this is not a tutorial to learn about Spring Boot REST API. I assumed you already familiar with this technology.

Spring Boot REST API - Spring Bean Scope illustration

We already know that Spring defines 5 types of bean scopes:

a) singleton
b) prototype
c) request
d) session
e) globalSession

Last three scopes are only available on web-aware application. Singleton and prototype are spring’s core scope and singleton is the default scope.