Roy Tutorials

Introduction In this example I am going to show you how to call REST APIs using javax.net.ssl.HttpsURLConnection. So, I am using plain Java code to send or receive data to or from the REST APIs. I am also going to show you how to send authentication token in the HTTP header. I am also going to show you how to use…

Introduction In this tutorial I am going to show you how to build Spring Boot Angular CRUD Application. CRUD is an acronym and stands for Create, Read, Update and Delete operations performed through an application or APIs. Using Spring Boot application I will build REST APIs which will be used to perform CRUD operations on server side resources. The Angular…

Introduction Here I am going to show you how to build an application using Angular for authenticating a user using Okta SSO (Single Sign On) with PKCE. Okta is an enterprise level identity provider that helps you to enable Single Sign-On across applications within an enterprise. Angular is a single page application (SPA) and it is recommended that you use…

Introduction Are you getting logon denied error while starting or deploying your Spring Boot application into Pivotal Cloud Foundry (PCF) cloud environment? Generally, logon denied error occurs while your application is trying to connect to database server. The error you get in your application log is similar to the following error: From the above error message it is clear that…

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 broker… completed with 0 plugins….

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, etc. Among these branches there…

Multiple Rows Deletion 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 on an HTML…

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 you need to mention Group…

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 will use Spring Data JPA…

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 server side, and you are…