Roy Tutorials

Introduction Here I am going to build a system to log online user activity in Spring Boot applications using HandlerInterceptor interface. As an application owner you may want to track your user activities, such as, which page they are accessing, from where requests were made to your application, from which pages to which pages they…

Introduction Here I will discuss about OWASP top 10 securities considerations in web applications. These applications could be anything from standalone to enterprise to web applications. OWASP is an acronym that stands for Open Web Application Security Project (OWASP) and it is a global community that continuously focuses on the improvement of all types of…

Introduction You might have seen the error in CodeIgniter 4: The framework needs the following extension(s) installed and loaded: curl, intl. I will show you how here to solve this problem. This problem generally you will find in PHP based CodeIgniter 4 web framework in your environment when you try to run your application using…

Introduction Here I am going to tell you how to manually move WordPress site to local server. In this tutorial I am going to show you only the manual process and I won’t use any plugin to move live WordPress site to local server. I will show you here how to move your live WordPress…

In this tutorial I am going to show you how to configure PHP, MySQL, Apache HTTP Server for developing PHP based web applications. You may create PHP based standalone applications or web based applications and you want to run them in development environment before deploying into the production or live environment. I will also show…

Introduction Apache POI is the most popular library when comes to manipulate word, excel, ppt based documents. In this example I am going to show you how to read large excel file using Apache POI library. Your large excel file may contain various kind of information, such as, Human Resource data, Sales data, Credit Cards,…

Introduction In this tutorial I am going to show you how to call Spring REST APIs concurrently using Java CompletableFuture. So basically REST service APIs will be invoked parallelly and in parallel execution the response time will be very less. I am going to show you how to call REST APIs concurrently using Java 8…

In this example you will see what are Predicate and Function functional interfaces in Java 8 or later version of Java. Functional interfaces provide target types for lambda expressions and method references. Each functional interface has a single abstract method, called functional method for that functional interface, to which the lambda expression’s parameter and return…

Introduction Here in this tutorial I am going to discuss about working principle of content security policy (CSP) in web applications. What if you want to minimize attacks on your website, what if you want to restrict the content to be displayed on your web site for some security reasons, what if you want to…

Introduction Here in this tutorial I am going to show you how to work with Apache Kafka consumer and broker failover in multi-broker clusters. Kafka is a distributed event streaming platform that lets you read, write, store, and process events (also called records or messages in the documentation) across many machines. Example events are payment…

Table of Contents Introduction Prerequisites Download Large File Using WebClient Using RestTemplate Testing the APplication Source Code Introduction Here in this tutorial I am going to show you how to download large file using Spring REST API. Generally when you download a file, your file is stored into file system or you load it into…

Introduction Here in this tutorial I am going to show you how to use AJAX technique using jQuery with Spring Boot application to check user availability instantly without refreshing the web page. I am going to use Thymeleaf template in Spring Boot application. I will use Spring REST to create REST API endpoint which will…