Roy Tutorials

Introduction In this tutorial I am going to explain about few common startup problems or errors of RabbitMQ server after a fresh installation. I am using 3.6.1 version of the RabbitMQ message broker. RabbitMQ Startup Errors You might have faced the following errors during starting the RabbitMQ message broker after installation in your system. Starting…

Introduction Here in this tutorial I am going to explain what are the different branching strategy in Git repository, I will talk about different git branching workflows and how to work with different branches in Git repository. You might have heard of or seen different branches in Git repository, such as, master, develop, feature, release,…

Introduction Here I am going to build an example on how to select multiple rows from HTML table and delete these multiple selected table rows from MySQL database using CodeIgniter 4 with the help of AJAX technique in jQuery. In this tutorial I am going to fetch all records from the MySQL database and displaying…

Introduction Here I will show you how to create maven project using CLI. CLI means command line interface, so you need to use command line tool (cmd prompt) in Windows or Shell terminal in Unix based system. You can use any IDE (for example, Eclipse) or tool to create a new maven project. During project creation…

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…

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…

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…

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…

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…

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…

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…

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…