ElasticSearch Create, Query, Delete Index – Java Example
ElasticSearch Java APIs can be used to create, update, query (retrieve items) and delete the index. In this post, you will learn about using Java APIs for performing CRUD operations in relation with managing indices and querying items in ElasticSearch. Create an empty index with data type mapping Create/update the index using BulkRequest APIs Search Index using QueryBuilder and SearchRequestBuilder APIs Delete the index Create an Empty Index with Data-type Mapping Create/Update the Index using BulkRequest APIs Pay attention to some of the following: Create an instance of TransportClient Prepare bulk request for inserting multiple entries in index Delete the Index Pay attention to some of the following: Create an …
ElasticSearch Fuzzy Query Example in Java
ElasticSearch fuzzy query can be used in scenarios when the user searches with mistyped keywords or misspellings. Alternatively, it can also be used for performing the search for similar words based on Levenshtein Edit Distance, which can be defined as the minimum number of single-character edits (insertions, deletions or substitutions) required to change one word into the other. In this post, Fuzzy Search using ElasticSearch Java API is demonstrated. Some of the following points are covered: Getting Setup with ElasticSearch and Kibana ElasticSearch Library POM Entries Using Fuzzy Query API for fuzzy search Using Match Query API for fuzzy search Using Bool Query API for Fuzzy Search Getting Setup with …
Spring Boot JPA MySQL Sample App – Code Example
Creating a Spring Boot app with MySQL data source is something every Java developer come across when thinking of creating a quick POC or app. This post is aimed to provide quick code samples which can be used to quickly create a MySQL-based Spring boot app. In this post, you will learn about code examples in relation to getting setup with Spring Boot app which interacts with MySQL database. The following are some of the topics covered: Define properties in application.properties file Create/Configure Database-related Beans Create Entity Classes (Domain) Create Database Implementation Classes (DAOs) Define Service Classes for interacting with Data Access Objects Invoke service class from SpringBoot main program …
AWS Error 2003 – Can’t Connect to RDS MySQL Server
In this post, you will learn about the solution to the error, AWS Error 2003: Can’t Connect to RDS MySQL Server, which you may come across while trying to connect AWS MySQL RDS server from your local machine (laptop or desktop). I came across this error when I first created an RDS MySQL instance using AWS console and tried accessing the instance from my laptop using the command such as mysql -h endpoint_address -P 3306 -u username -p. The following represents the error: As a matter of fact, I have come across this error once in a while trying to connect the MySQL database app from the command prompt or the application. The solution works …
Get Started with ElasticSearch and Kibana on Windows
ElasticSearch is a distributed, restful analytics search engine which is used to provide faster search through your data than the traditional databases including RDBMS and NoSQL databases. It works by regularly creating data indices from the data stored in traditional databases and use Lucene library to search through the data. Kibana is the visualization client used to explore, visualize and discover the data. In this post, you would learn about some of the following: Setup ElasticSearch and Kibana on Windows Load Sample Data and play around Setup ElasticSearch and Kibana on Windows Setup ElasticSearch on Windows: Go to the elasticsearch installation page and download the file elasticsearch-6.2.2.zip. Follow the instructions on the page …
AWS DynamoDB PutItem Java Example to Create Items
In this post, you will learn about Java code example related to creating an entry in the DynamoDB table using PutItem API. The following are some of the points considered later in this article: Configure Dev Environment with AWS Credentials Update POM.xml or Gradle file to include DynamoDB library Use PutItem API to create an Item in DynamoDB table PutItem API example with Spring Boot app Configure Dev Environment with AWS Credentials Make sure you have configured your dev environment with appropriate Access Key ID and secret access key. You could do that by executing the command such as following: If you have configured it correctly, you should be able …
DynamoDB – Partition Key vs Composite Partition Key
AWS DynamoDB has two key concepts related to table design or creating new table. A beginner with DynamoDB is found to be wondering on whether to use a partition key or composite partition key when creating a new table. Composite partition key is also termed as composite primary key or hash-range key. In this post, you will learn about some of the following: Is the partition key same as the primary key of a table? What are composite partition key or composite primary key? When to use partition key vs composite partition key? This post presumes that you have got a good understanding of partition concept and how DynamoDB stores …
Build IVR System using Amazon Polly, 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 …
Amazon Polly Text-to-speech with AWS S3, Twilio Java App
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 …
Java Code to Invoke Twilio Rest API to Play Audio
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 …
Twilio & AWS S3 using Java & Spring Boot – Code Example
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 …
AWS Temporary Credentials with Java & Spring Boot
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 https://sts.amazonaws.com. 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 …
10 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 …
Amazon S3 with Spring Boot & Java – Sample Code
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 …
Amazon Polly Hello World with Java & Spring Boot
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 …
Spring Boot CommandLineRunner Code Example
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 …
I found it very helpful. However the differences are not too understandable for me