RESTful Web Services

An Important Property of Modern Web Apps is Resilience. In simple words, resilience is the ability of a system’s feature to fail gracefully without impacting the entire system. In the case of web apps, we want to make sure that the entire system will not be down if a remote service (a database, API Server)…

Read More Enforcing Resilience in a Spring Boot App using Resilience4J

Multiple data source implementations are very crucial in instances where we want to secure the application from vulnerabilities such as a database failure. This will ensure that the application can still function even if part of the database went down. This tutorial will use student and course entities to demonstrate how multiple data sources can…

Read More Multiple Datasources in Spring Application

In this tutorial on Spring Cloud you will learn how to create your own Spring Cloud Config Server and also, how to configure a Spring Boot Application to be a Spring Cloud Config Client. Spring Cloud Config Server Spring Cloud Config Server is a Spring Boot application. So to create our own Spring Cloud Config…

Read More Spring Cloud Config Server and Config Client

In this short tutorial, I am going to share with you how to switch your Spring Boot app, at runtime, to use a different logging level. Set Logging Level for a Package in Your App Let’s assume we have a Spring Boot Web Application with the following method in a Rest Controller class. @RestController @RequestMapping(“/users”)…

Read More Switch Logging Level in Spring Boot at Runtime

In this tutorial, you will learn how to add a Social Login(OAuth 2) feature into your Spring MVC Web application. This will allow users to login to your application with their social network accounts like Facebook, Google, or other large services that support OAuth 2 like for example GitHub. Spring Security 5 offers very good…

Read More Spring Security OAuth 2 Social Login

In this tutorial, you will learn how to use @AuthenticationPrincipal annotation to get the Jwt object containing the details of a provided in HTTP Request access token. When we send a request containing an access token in the Authorization header, behind the scenes,  Spring Framework will do a lot of work and if all is good,…

Read More @AuthenticationPrincipal – Getting the Jwt Claims

By default, Spring Boot RESTful Web service endpoints consume and produce JSON representation. But we can easily make our RESTful Spring Boot Web service endpoints consume and produce an XML representation of a resource as well. Add XML Support to Spring Boot Project To make our Spring Boot project consume and produce an XML representation…

Read More Consuming XML in Spring Boot REST

HATEOAS is a way to make your RESTful Web Service endpoint, automatically include links to other Resources of your API, in the response that it sends back to a calling client application.  The client application that consumes your web service endpoint, can then use those links, to consume other RESTful Resources that your Web Service…

Read More Add HATEOAS to Spring Boot RESTful Web Service

In this Spring Security tutorial, you will learn how to use the @PreAuthorize annotation to secure method invocation. You can use the @PreAuthorize annotation to secure either method in a Controller class or a method in a service layer class. There are other useful method level security annotations like the ones below. It is useful…

Read More Spring Security @PreAuthorize Annotation Example

In this Spring Security tutorial, you will learn how to enable and use the Method Level Security with @Secured annotation. There are other useful method level security annotations like the ones below. It is useful to know how they work as well. @PostAuthorize Security Annotation Example, @PreAuthorize Security Annotation Example. If you are interested in video…

Read More Spring Security @Secured Annotation Example

In this tutorial, you will learn how to make Zuul API Gateway pass an Authorization header to a downstream Microservice. To learn how to make Spring Boot Microservice read HTTP Request headers, please read this tutorial: Read HTTP Request Header in Spring MVC. Configure Zuul API Gateway to Forward an Authorization Header By default, Zuul…

Read More Pass Authorization Header to Downstream Microservice

In this tutorial, I am going to share with you how to generate a self-signed certificate and enable HTTPs/SSL support in a Spring Boot application. You will also learn how to configure RestTemplate HTTP client to use the same self-signed certificate to communicate with your Web Service over HTTPs. Let’s start by generating a self-signed…

Read More Enable HTTPs/SSL in Spring Boot App

In this Spring Boot tutorial, you will learn how to get the details of the currently authenticated principal user. There is more than one way to get currently authenticated user details and in this blog post, I am going to share with you a few. Most likely you already have Spring Security configured for your…

Read More Spring Security. Get Authenticated Principal Details.

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