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Namastecode
Namastecode

Harpal Singh

Hi, I am Harpal, a software engineer from Italy. I created Namaste Code to share my knowledge and experience with the world. I hope you find the content useful. 😄

Create Docker Image From Java Application
Java Docker Spring-Boot Containerization DevOps
Learn how to create a Docker image from a Java application by configuring Maven to package the app as an executable JAR, then building a lightweight container using a Dockerfile.
How to Upload File in Spring Boot
Spring Spring-Boot File-Upload Thymeleaf
Learn how to implement file uploads in Spring Boot, configure size limits, and handle potential errors gracefully using Thymeleaf and Spring MVC.
Http Requests With Rest Client in Spring Framework 6
Spring Restclient HTTP Rest Openai
This tutorial explains how to use the RestClient API in Spring 6.1 for making HTTP requests. We cover setting up and customizing the RestClient, handling requests (GET, POST, PUT, DELETE), and provide an example of using it with the OpenAI API. We also discuss error handling. By the end, we’ll know how to effectively use RestClient in our projects and understand its advantages over RestTemplate.
Create a RAG Chatbot With Spring AI
Spring-Ai Rag Vaadin Web Pgvector
This guide explains how to create a Retrieval-Augmented Generation (RAG) chatbot using Spring AI and Vaadin. It covers project setup, application configuration, backend and frontend development, document parsing with TikaDocumentReader, embedding generation with OpenAI, and storage in PostgreSQL using PGvector. It also shows how to build a chat interface for interacting with uploaded documents.
Understanding Spring's @Scheduled Cron Syntax
Spring Cron Scheduling
Learn how to use the @Scheduled annotation in Spring with cron expressions.
Configuring Multiple Data Sources in a Spring Boot
Spring Database
Learn to configure multiple data sources in a Spring Boot application, enabling the use of separate databases and specific data sources for Spring Data JPA repositories.
Testcontainers in Spring Boot Integration Tests
Spring Testcontainers Testing
Learn how to use testcontainers in a Spring boot application when creating integration tests.
Get Values Defined in Properties File in Spring
Spring Properties Basics
Learn how to access values defined in a properties file in a Spring Boot application. Define properties in a properties file and access them in a Spring service.
Returning HTTP 4XX Errors in a Spring Application
Spring HTTP
Learn how to return HTTP 4XX errors in Spring applications. Use ResponseEntity to set the appropriate HTTP status code and response body.
Configuring the Port for a Spring Boot Application
Spring Basics
Learn how to configure the server port for a Spring Boot application. Set the port in the application.properties file, command-line arguments, or system properties.