Knowledge Factory

This guide walks you through setting up a Spring Boot application with a Resilience4j Circuit Breaker , ensuring fault tolerance. You will learn how to create a REST API, configure circuit breaker settings, write unit tests, and package the application for deployment. By the end of this guide, you'll have a fully functional Spring Boot project that can handle failures gracefully and be easily extended for production use. 1. Prerequisites Make sure you have the following installed: Java 17 or later Maven (Apache Maven 3.6+) An IDE (e.g., IntelliJ IDEA, Eclipse, or VS Code) 2. Project Setup Create a Maven Project You can set up a Maven project manually or by using Spring Initializr. Here, we’ll create the project manually. Project Structure spring-boot-demo/ ├── src/ │ ├── main/ │ │ ├── java/ │ │ │ └── com/ │ │ │ └── example/ │ │ │ └── demo/ │ │ │ ├── DemoApplication.java │ │ │ └── controller/ │ │ │ ...

Here's a breakdown of each section: 1. User Registration Step 1 : The user sends a POST request to the /auth/register endpoint with their username and password. Step 2 : The Flask App checks the database to see if the user already exists. Step 3 : If the user doesn't exist, the app saves the new user with a hashed password to the database. Step 4 : A success message is returned to the user. 2. User Login Step 1 : The user sends a POST request to /auth/login with their credentials. Step 2 : The Flask App validates the credentials against the database. Step 3 : If valid, the app generates a JWT access token. Step 4 : The token is sent back to the user for future authentication. 3. Accessing a Protected Route Step 1 : The user sends a GET request to /auth/protected with the JWT token in the Authorization header. Step 2 : The app validates the token using the JWT service. Step 3 : If the token is valid, the app retrieves the user's identity from the database. Step 4 : A s...

PayPal is one of the most widely used payment platforms globally, making it an excellent choice for adding payment functionality to your web applications. In this guide, we’ll walk you through integrating PayPal with a Python Flask application from scratch. You’ll learn how to set up your environment, configure PayPal’s REST API, create and execute payments, and test the integration. By the end, you’ll have a fully functional payment flow that you can expand for your specific needs. Step 1: Setup Your Environment Install Python Ensure you have Python 3.7+ installed. You can download it from Python's official website . Create a Flask Project Create a new directory for your project and set up a virtual environment: mkdir flask-paypal-integration cd flask-paypal-integration python - m venv venv source venv/bin/activate # For Windows, use `venv\Scripts\activate` pip install flask Install Required Libraries Install Flask and the PayPal SDK: pip install flask flask-cors paypalrest...

Query caching in Spring Data JPA helps improve performance by reducing database access for frequently executed queries. By caching query results, subsequent requests for the same query fetch data directly from the cache instead of executing a database query. This guide demonstrates how to implement query caching using Hibernate's second-level cache with Spring Data JPA and Ehcache. Step 1: Set Up the Project Add Maven Dependencies Include the following dependencies in your pom.xml file: <dependency> <groupId> org.springframework.boot </groupId> <artifactId> spring-boot-starter-data-jpa </artifactId> </dependency> <dependency> <groupId> org.springframework.boot </groupId> <artifactId> spring-boot-starter-web </artifactId> </dependency> <dependency> <groupId> com.h2database </groupId> <artifactId> h2 </artifactId> <scope> runtime </sco...

This guide will show you how to create a simple Spring Boot project using Spring Cloud Function to implement a serverless function. You’ll learn how to set up a project, create a greeting function, expose it as a REST endpoint, and deploy it to a cloud environment like AWS Lambda or Azure Functions. By the end, you'll have a scalable, cloud-ready function. Let’s get started! Step 1: Create a Spring Boot Project via Spring Initializr Visit Spring Initializr : Go to https://start.spring.io/ . Configure Project Metadata : Project : Maven Project Language : Java Spring Boot : 3.4.2 (or latest version compatible with your setup) Project Metadata : Group : com.example Artifact : spring-cloud-function-demo Name : spring-cloud-function-demo Description : Demo project for Spring Cloud Function Package Name : com.example.springcloudfunctiondemo Packaging : Jar Java Version : 17 (or any version compatible with Spring Boot 3.4.2) Add Dependencies : Spring Web Function Generate Project : Click...