Roy Tutorials

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 project and probably you might…

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 I am going to use…

Scenario 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 attempting to use an…

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 can check my tutorial about…

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 you download a large file…

Criteria Delete 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 the persistent context is…

Criteria Update 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 the persistent context is…

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 class. Caching is used to…

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. Flask development server provides such…

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 form elements, Text Helpers perform…