Search results for: Open API

In this article, we will cover the basics of Aspect-Oriented Programming (AOP). You will learn how to use AspectJ to provide different AOP advices to Spring Boot applications to support cross-cutting issues like logging, profiling, caching, and transaction management and finally we will do a practical implementation to record user operations using Spring Boot AOP.…

Read More A guide to Spring Boot AOP to Record User Operations

In this tutorial, you will learn about JUnit5 Lifecycle methods. A Lifecycle Method is any method that is directly annotated or meta-annotated with @BeforeAll, @AfterAll, @BeforeEach, or @AfterEach. Let’s have a look at these annotations one by one. @BeforeAll When a method is annotated with @BeforeAll it means that the method should be executed before…

Read More A Guide to JUnit5 Lifecycle Methods

In this lesson, you will learn how to read URL query string parameters in your Spring MVC web application.   @RequestParam annotation Let’s assume that we need to create a method that needs to return a list but is limited to a certain number. To make our method read URL Query String Parameters, we will…

Read More Spring Web MVC – Reading URL Query String Parameters

synchronized void method() {} public class SynchronizedInstanceMethodExample implements Runnable { public static void main(String[] args) { SynchronizedInstanceMethodExample runnable = new SynchronizedInstanceMethodExample(); new Thread(runnable).start(); // creates one thread new Thread(runnable).start(); // creates second thread } // Inherited run method from the Runnable interface @Override public void run() { try { // Calling the non-synchronized method print()…

Read More Java Synchronized Blocks and Methods

In this guide, you will learn to use @RepeatedTest and @ParametrizedTest annotations introduced in JUnit 5. We’ll look at the capability that lets us run a test a certain number of times.  We’ll also look at interfaces that will allow us to retrieve information about the repeated tests.  Moreover, we will also look at a…

Read More A Guide to @RepeatedTest and @ParametrizedTest in JUnit 5

class PrintArrayElementsExample { public static void main(String[] args) { int[] arr1 = {1, 7, 9, 5, 2, 8, 3}; String[] arr2 = {“Megan”, “Tom”, “Melissa”, “John”, “Steve”}; // print elements of the arr1 System.out.println(Arrays.toString(arr1)); // print elements of the arr2 System.out.println(Arrays.toString(arr2)); } } Output: [1, 7, 9, 5, 2, 8, 3] [Megan, Tom, Melissa, John,…

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public class SplitString { public static void main(String[] args) { String names = “Tom,Steve,John,Megan,Melissa”; // split string String[] arr = names.split(“,”); // print the size of the array System.out.println(arr.length); // print the elements Stream.of(arr).forEach(System.out::println); } } Output: 5 Tom Steve John Megan Melissa   If you need a list, instead of an array, use the…

Read More Split a comma-separated String in Java

In this tutorial, you will learn how to secure access to User’s Data in RDS using Lambda Authorizer. First, the Lambda Authorizer function will authenticate the caller by validating JWT using nimbus-jose-jwt library. After that, the Lambda Authorizer function will return an output object containing an IAM policy. The Authorizer will also return additional information…

Read More Lambda Authorizer – Secure Access to User’s Data in RDS

In this tutorial, we will read user data from AWS RDS with an access token. You can have a look at the following tutorials before moving ahead. Build and deploy a Serverless Spring Boot Web Application with AWS Lambda AWS Lambda with Spring Boot – A Simple GreetMe Example Amazon Cognito User Authentication in Spring…

Read More Reading user data from AWS RDS with an access token

In this article, you will learn about RabbitMQ and explore its common use cases. I will also guide you step-by-step on how to implement messaging using RabbitMQ in a Spring Boot application. By the end of this article, you will know how to publish and consume messages in a queue. So let’s get started! What…

Read More Messaging with RabbitMQ in Spring Boot Application

In this tutorial, we are going to see how to insert records into a DynamoDB table using an AWS Lambda function written using Spring Boot Java. We are also going to add an AWS API Gateway trigger to the Lambda function and see how it works. To follow this tutorial, make sure that you have…

Read More Writing into DynamoDB in a Spring Boot App using AWS Lambda

In the previous blog post, we have covered how to grant access to certain endpoints based on the Role configured through code. As we know, Keycloak is the Identity and Access Management solution that provides out-of-the-box authentication and authorization services. One of the services includes a Fine-Grained Authorization Service. Fine-Grained Authorization Service provides businesses with…

Read More Fine-grained Authorization Services in Keycloak with Spring Boot