Introduction In this post you will see an example about Angular Spring Boot Security JWT (JSON Web Token) Authentication and role based Authorization for REST APIs or RESTful services. I won’t explain here about JWT as there is already very good article on JWT. I will implement Spring Security’s UserDetailsService to load user from database. I…

Posted in Angular Spring Boot

Angular Spring Boot Security JWT Authentication And Authorization

Introduction In this tutorial I will use Spring Data JPA Pageable to build REST API for pagination in Spring Boot applications. Here, I am going to show you how to build pagination using Bootstrap jQuery – AJAX with Spring Boot applications. Using jQuery – AJAX, you don’t need to load or fetch all records from…

Posted in Spring Boot Spring JPA

Bootstrap AJAX Spring Boot Pagination

Introduction Are you stuck or confused how to build a Java or Spring Boot project when your system has multiple versions of Java or JDK installed? I will show you how to use specific jdk version for gradle build. Java version might be different in your classpath than what you want to use in your…

Posted in Gradle

How To Use Specific JDK Version For Gradle Build

Introduction In this example I will show you how to extract text from images in Python program. The text extraction from image could be used for various purpose, for example, data mining for machine learning projects, reading the content from images can be used for further processing in your applications. To extract text from image…

Posted in Python

How To Extract Text From Images In Python

You are using Node JS 17 and hitting this error during application start up using npm start command. Error The error ERR_OSSL_EVP_UNSUPPORTED has been mentioned in the release notes for Node.js 17. If you hit an ERR_OSSL_EVP_UNSUPPORTED error in your application with Node.js 17, it’s likely that your application or a module you’re using is…

Posted in NodeJS React JS

How To Fix ERR_OSSL_EVP_UNSUPPORTED In React JS Application

Introduction In this PHP example, I am going to show you how to call external REST APIs in PHP programming. I am not going to build here any new REST API, but I will call or consume those REST APIs which are already available for testing purpose. But if you want to know then you…

Posted in PHP REST

PHP Consume External REST APIs

Introduction Here in this tutorial example, I will show you how to download large file in PHP program. Generally, when you download a file, your file is stored into file system or you load it into memory as a byte array. This is not a problem when you deal with a small file but when…

Posted in File Download PHP

PHP Large File Download in Chunks

Introduction The new feature bulk delete operation in Criteria API was added in JPA 2.1. I will show you an example how to perform bulk delete using Spring JPA CriteriaDelete. The CriteriaDelete interface can be used to implement bulk delete operations. Delete operations performed through CriteriaDelete interface are directly mapped to database delete operations. Hence…

Posted in Spring Boot Spring JPA

Bulk Delete Using Spring JPA CriteriaDelete

Introduction The new feature bulk update operation in Criteria API was added in JPA 2.1. I will show you an example how to perform bulk update using Spring JPA CriteriaUpdate. The CriteriaUpdate interface can be used to implement bulk update operations. Update operations performed through CriteriaUpdate interface are directly mapped to database update operations. Hence…

Posted in Spring Boot Spring JPA

Bulk Update Using Spring JPA CriteriaUpdate

Introduction In this example, I am going to discuss about how to work with Python flask caching. Flask is a Python based light-weight web frameworks. Flask framework provides an extension called Flask-Caching that adds caching supports for various backends to any flask applications. You can also develop your own caching system by extending the flask_caching.backends.base.BaseCache…

Posted in Flask MySQL

Python Flask Cache in Web Applications

Introduction In this example I am going to show how your application can reload changes without server restart in Flask applications in development environment. Situations may occur when you need to speed up your development works without having to worry about restarting the server for every change in the piece of code in your application….

Posted in Flask

Reload Changes in Flask Web App Without Server Restart

Introduction In this example I am going to discuss how to create custom helper functions in CodeIgniter 4. Helpers in CodeIgniter helps you with tasks. Each helper file is simply a collection of functions in a particular category. There are URL Helpers, that assist in creating links, there are Form Helpers that help you create…

Posted in Codeigniter

CodeIgniter 4 Custom Helper Functions