Introduction In this example you will see how to work with IN clause with WHERE condition in SQL statement in Spring Data JPA. I will use MySQL server for this example. I will fetch selected rows or multiple rows selection as well as I will delete selected rows or multiple rows deletion from the table using IN operator with WHERE…

Introduction We will see how to implement circuit breaker pattern using Hystrix in Spring Cloud Gateway. Hystrix is a library from Netflix that implements the circuit breaker pattern. The Hystrix GatewayFilter allows us to introduce circuit breakers to our gateway routes, protecting our services from cascading failures and allowing us to provide fallback responses in the event of downstream failures….

Introduction Here we will see how to use load balancer name or service name for Microservices instead of host, port for URI while building API gateway using Spring Cloud Gateway – the tutorial example which we have created earlier. We will use the same tutorial to use load balancer name instead of URL, such as, http://localhost:9000, http://localhost:9001, etc. for the…

In this tutorial we will build Spring Cloud Gateway for Microservices built using Spring Boot framework. Spring Cloud Gateway aims to provide a simple, yet effective way to route to APIs and provide cross cutting concerns to them such as: security, monitoring/metrics, and resiliency. Spring Cloud Gateway aims to provide a simple, yet effective way to route to APIs. When…

Introduction ServletConfig is used by only single servlet to get configuration information, whereas ServletContext is used by multiple objects to get configuration information. ServletConfig object is one per servlet class and destroyed once the servlet execution is completed. ServletConfig object gets created during initialization process of the servlet and this object is public to a particular servlet only.

IN, OUT, INOUT Params In this tutorial I will show you how to work with IN, OUT and INOUT parameters in Stored Procedure using Spring Data JPA. I will also call a stored procedure having no parameter at all. I am going to use MySQL server, so there may be some limitations on MySQL server or there may be some…

Introduction In this tutorial I will show you how to map custom query results into DTO in Spring Data JPA. Situations may occur while you are unable to return the entity object(s) as results from your Spring Data JPA Repository and instead you need to write custom query or native query for your business requirements. So in such situations you…

REST API Documentation This tutorial will show you an example on how to document REST APIs using OpenAPI 3. When creating a REST API, good documentation is instrumental. Here I will use OpenAPI 3 in Spring application for creating documentation for REST APIs. I will create and deploy REST services but I do not have an option to let others…

Introduction The tutorial, REST over HTTPS with client certificate authentication, will show you how we can use client certificate to handshake with server along with basic authentication for consuming the service. Even you can use header authentication along with client certificate to make more secure. I will create Spring Boot application on Spring REST API and build the application using…

In this tutorial we will see an example of event driven streaming using Spring Cloud Stream and Apache Kafka streaming platform. How do we deal with some events, such as, a new user has registered to a portal, an order was placed, a file has been uploaded etc? Let’s say when an order was placed then we need a call…