Category Archives: Java

Build IVR System using Amazon Polly, Lambda and Twilio

Build IVR with Amazon Polly, S3, Lambda and Twilio

Building an intelligent IVR system with a Bot handling the interaction with your end users and bringing in humans based on pre-defined events would bring a lot of automation and remove mundane manual activities which takes up lot of time for a person. This can be achieved using cloud services provided by cloud providers such as Amazon, Google, Azure etc and communication service providers such as Twilio. In this post, you will learn about how to create or build an intelligent or smart IVR system using some of the following: Use Amazon Polly to create one or more custom text-to-speech audios and store the same at predefined locations in AWS …

Continue reading

Posted in AI, AWS, Java, Tutorials. Tagged with , , .

Amazon Polly Text-to-speech with AWS S3, Twilio Java App

Amazon Polly - S3 - Twilio - Spring Boot - Java

Amazon Polly can be used with Twilio phone service and AWS S3 to create an automated alert system which does (achieves) some of the following: Convert text to speech (using Amazon Polly) Upload audio (speech stream) created using Polly service on AWS S3 bucket Use Twilio Call service to play the audio to the destined phone number The following represents the application architecture diagram (communication flow viewpoint) representing communication between  Spring Boot app and Amazon Polly, Amazon S3 and Twilio Service to achieve automated phone alerts based on text-to-speech conversion. This can be used to create automated alert/notification system around following use cases which makes phone call to concerned personal …

Continue reading

Posted in AI, AWS, Java.

Java Code to Invoke Twilio Rest API to Play Audio

Java and Twilio Rest API for Phone Calls

This post represents sample Java code (example) to demonstrate how to invoke Twilio Rest API to play pre-recorded audio in a phone call made to the users. The code could be used to in some of the following usecase: Alert users via phone call in relation to different kind of critical events such as security issues, production downtime, production issues etc. Play different kind of messages to users in relation to different occasions such as birthdays, anniversaries etc. The code can be used to play audio stored at locations such as cloud platform storage (AWS storage, Google/Azure storage etc.) The key is to provide public access (READ permission) to these …

Continue reading

Posted in Java. Tagged with , .

Twilio & AWS S3 using Java & Spring Boot – Code Example

twilio and AWS S3 with Java and Spring Boot

Twilio is a very popular communication service which could be used to send SMS, make the phone or video calls to people in different countries. In this post, you will learn about creating Java and Spring Boot app in relation to how to use Twilio phone service to make a phone call and play audio stored at AWS S3 bucket. The following are some of the related use cases: Play security and other alerts via phone calls Play messages of any kind via phone calls The following are some of the topics which would be covered in this post: Define VoiceService interface defining APIs Create Twilio Voice Service implementation Load …

Continue reading

Posted in AWS, Java. Tagged with , , , .

AWS Temporary Credentials with Java & Spring Boot

AWS Temporary Security Credentials - AWS STS

AWS Security Token Service (STS) is an Amazon web service which enables you to request temporary, limited-privilege credentials for AWS Identity and Access Management (IAM) users or for users that you authenticate (federated users). By default, the AWS Security Token Service (AWS STS) is available as a global service, and all AWS STS requests go to a single endpoint at You can optionally send your AWS STS requests to endpoints in any of the AWS regions shown in the table that follows. In this post, you would learn how to use AWS security token service to create temporary security credentials with Spring Boot and Java app. I would recommend …

Continue reading

Posted in AWS, Java, Tutorials. Tagged with , , .

10 Spring Framework Interview Questions for Freshers

Spring framework interview questions for freshers

Spring Framework is one of the most popular and widely used Java frameworks which makes it very easy to create a Java application/web application using several out-of-box framework components provided by Spring. Thus, it is imperative that beginners starting to do Java web app would end up using Spring framework for building the app. From that perspective, it becomes of great importance for beginners to take note of some of the basic concepts related to which interview questions can be asked. In this post, you will learn some of the Spring framework fundamentals concepts which could be asked in form of interview questions and answers. These questions and answers may …

Continue reading

Posted in Career Planning, Freshers, Interview questions, Java. Tagged with , , .

Amazon S3 with Spring Boot & Java – Sample Code

amazon S3 with Spring Boot and Java

Amazon Simple Storage Service (S3) is an AWS object storage platform which helps you to store the files/data in form of objects, and, store and retrieve any amount of data from anywhere – websites and mobile apps, corporate applications, and data from IoT sensors or devices. Each file stored in Amazon S3 (as an object) is represented using a key. The following are some of the usecases where S3 could be used. Thus, it becomes of utmost importance to understand how to interact with Amazon S3 API using AWS SDKs including AWS Java SDK. Backup & recovery Data archiving Big data analytics Disaster recovery Cloud-native application data Hybrid cloud storage …

Continue reading

Posted in AWS, Java, Tutorials. Tagged with , , .

Amazon Polly Hello World with Java & Spring Boot

amazon polly with spring boot and java

Amazon Polly is one cool AWS service which can be used to achieve requirements such as creating business, security alerts via phone call. When integrated with communication providers such as Twilio, several value-added services could be created using Amazon Polly AWS service. In this post, you will learn about creating a sample Java app which uses Amazon Polly service for converting text to speech. You should be able to listen to the following text using the program given below: Hello World! How are you doing? This is Polly. I am happy to talk with you. The following are some of the aspects covered in this post: Create a Spring Boot app …

Continue reading

Posted in AI, AWS, Cloud, Java, Tutorials. Tagged with , , , .

Spring Boot CommandLineRunner Code Example

spring boot app using command liner

Spring Boot helps you quickly get started with building a Spring-based web app in no time. All you need to do is go to Eclipse IDE, create a new Spring Starter Project and that is it. This is provided you installed Eclipse plugin, Spring Tools (aka Spring IDE and Spring Tool Suite) by going to Help > Eclipse Marketplace… and searching for “spring tools” keyword. Often, one wants to run a Spring Boot app as a Java application as like a traditional Java program and test different parts of their app. In this post, you will get a template code for quickly getting started with Command Liner which would help …

Continue reading

Posted in Java, Tutorials. Tagged with , , .

Spring Boot & Angular App Hello World as One Deployable War

deploying spring and angular app as deployable war

This article represents steps and related code samples to deploy an Angular app (created with Angular 2.*, Angular 4.* or Angular 5.*) with a Spring Boot / Spring Web app as one deployable unit (war file) on the web server such as Tomcat, Jetty etc. Different Deployment Strategies for Spring Boot and Angular App The following are the two different strategies which can be used for deploying web app built with Angular 5.* (and previous versions such as Angular 4.* or Angular 2.*) used for doing client side programming and Spring boot with Spring Web for server-side programming. Deploy Angular App and Spring Boot / Spring Web app as different applications running on different servers; This implies that users connect …

Continue reading

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

Top 5 Java Rule Engine for 2017-2018

Java rule engine 2017 2018

This is a list of top 5 rules engine which can be used in your Java application. Out of below 5 frameworks, Drools is the most popular one. Popularity Rule Engine Summary 1 Drools A Business Rules Management System (BRMS) solution which provides a core business rules engine (BRE), a web authoring and rules management application (Drools Workbench) and an Eclipse IDE plugin for core development 2 OpenRules A general purpose business rules and decision management system 3 EasyRules EasyRules provides the Rule abstraction to create rules with conditions and actions, and the RulesEngine API that runs through a set of rules to evaluate conditions and execute actions. 4 JLisa A Clips-like Rule engine accessible from …

Continue reading

Posted in Java, News, Tools. Tagged with .

Spring Framework Interview Questions & Answers – Set 1

Spring framework interview questions and answers

This is a practice test / interview questions and answers for Java Developers working on Spring Framework. These questions can be used to check your knowledge on Spring framework fundamentals. They could be useful and helpful in preparing you for upcoming interview in relation with Spring framework. The following are some of the topics in relation with Spring Framework Fundamentals which are covered in this practice test: Spring IOC concepts Configuration metadata Beans packages for IOC container Beans instantiation Different types of DI techniques (Constructor-based, Setter-based DI) Beans initialization (Eager / lazy initialization) Method injection techniques (lookup method, arbitrary method injection) Bean Scopes (Singleton, Prototype, Request, Session, Application, WebSocket) Practice Test on Spring Framework Fundamentals

Posted in Interview questions, Java, Web. Tagged with , , .

Top 10 Tricky Interview Questions for Java Developers

Java interview questions

Here is a list of top ten (10) tricky / popular interview questions and answers for Java developers. I got these questions out from Stackoverflow. You are a Junior or Intermidiate level Java developer and planning to appear for Java developer interviews in near future, you would find these questions to be useful enough. Q1: Is Java “pass-by-reference” or “pass-by-value”? Ans: Java is always “pass by value”. Read the details on this page, Is Java “pass-by-reference” or “pass-by-value”? Q2: How to create a memory leak in Java? Ans: This is possible by making use of Class loader and ThreadLocal. Read the details on this page, Creating a memory leak in Java Q3: What is difference between package private, public, protected, and private? Ans: A private member …

Continue reading

Posted in Interview questions, Java. Tagged with , .

Spring Boot App on Google App Engine Standard Environment

This blog represents tips and techniques on how to deploy a Spring Boot app on Google App Engine standard environment. Create a Google AppEngine (GAE) Project Login into Google Cloud Console and create an AppEngine project. Configure GCloud Setup In order to upload GAE project from command prompt, the GCLoud setup needs to be configured. Execute following command from the command prompt to start configuring your appengine project: Do some of the following while configuring the setup: Select a new configuration; Enter the configuration name Login into your cloud account Successful login will list down existing Google Appengine (GAE) project. Pick the one which you created from the cloud console. …

Continue reading

Posted in Google Cloud, Java, Web. Tagged with , , .

Setup Environment for Google AppEngine Java Project

This blog presents tips and techniques on how to set up environment for deploying Java web app on Google AppEngine using GCloud SDK. Same environment can as well be used for deploying Spring boot web app. Following steps are described later: Install Google Cloud SDK Install Cloud SDK Appengine Java component Create Appengine project in Google Cloud Console Authorize GCloud Configure Appengine project using GCloud Install Google Cloud SDK Download and install Google Cloud SDK. The instructions for downloading and installing Google Cloud SDK can be found on Installing Cloud SDK page. Unzip or Untar the downloaded file and go to the google-cloud-sdk folder. Execute or install.bat appropriately from …

Continue reading

Posted in Cloud, Google Cloud, Java, Web. Tagged with , , .

Spring Boot with JSP Pages – Code Example

Following needs to be done to setup Spring boot web app with JSP pages Create a Spring Starter Project Create a Spring Starter Project by selecting “Web” as one of the dependencies. This will create a Springboot project. POM.xml Entries Place following entries in pom.xml for processing JSP pages Configuration in Place following configuration in Create Controller class Create a sample controller class such as following: Create JSP pages Create a folder src/main/webapp/WEB-INF/views Create a file index.jsp. Place the content such as following: Run Project as Spring Boot App Access URL such as http://localhost:8080/ in browser. Following would be displayed.

Posted in Java, Web. Tagged with , , .