Introduction In this example I am going to show you Spring Security Pre-authentication hasrole with Spring Data JPA. In my another example I had shown the similar example on Spring Security Pre-Authentication with Spring JDBC Template. There are situations where you want to use Spring Security for authorization, but the user has already been reliably…

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 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…

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 memory as a byte array. This is not a problem when you deal with a small file but…

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…

Introduction In this tutorial I am going to show you an example on Spring Cloud Gateway Security with JWT. JSON Web Tokens (JWT) are an open, industry standard RFC 7519 method for representing claims securely between two parties. JWT.IO allows you to decode, verify and generate JWT. The Spring Cloud Gateway sits in front of…

In this tutorial I am going to discuss about what is Whitelabel Error Page and how to deal with Whitelabel Error Page in Spring Boot applications. Spring boot allows you to setup a Spring based application with minimal configurations. Spring MVC applications provide no default (fall-back) error page out of the box but Spring Boot…

Here in this example I am going to show you how to allow users for OAuth2 SSO (Single Sign On) using AWS (Amazon Web Services) Cognito. I had explained how to do OAuth2 Single Sign On using Spring Boot and GitHub account. Here I am going to use AWS Cognito. You can use any other…

Introduction Here I am going to show you an example on how to return different data formats from REST API using Spring Boot framework. You may have a requirement that you need to return multiple formats, such as XML, JSON, etc., from the REST response, then this example may help you. This example will return…

Introduction Here I am going to write Junit test case for testing multiple files upload in Spring REST Controller. I have already created how to upload multiple files using Spring REST API and I also had shown how to test it through REST client tool – Postman. In this tutorial I am going to use…

Introduction Here in this tutorial I am going to show you how to upload multiple files using Spring Boot REST API. I had also shown you in my another example how to upload single file using Spring Boot REST API framework. For uploading file(s) you can use any client, for example, browser or any REST…

Introduction I am going to discuss here how to perform asynchronous request processing via Spring’s DeferredResult class. A DeferredResult can be used when the application wants to produce the return value from a thread of its own choice. A DeferredResult is what is possibly not-yet-finished computation that will be available in future. Spring MVC 3.2…