DEV Community: Hirushi Nethmini

Hibernate vs JPA: Two Names, One Persistent Confusion

Hirushi Nethmini — Tue, 10 Feb 2026 06:25:04 +0000

Introduction

As a software engineer, I work with Java Spring Boot projects. For some projects, we use Spring Data JPA, while in others, we use Hibernate. Then I came across a little confusion: what is the difference between Spring Data JPA and Hibernate? I believe that many of you have the same question.

In earlier versions, developers relied on JDBC, which required repetitive SQL queries, manually set mappings, and extensive boilerplate code. As applications grow, managing this becomes difficult, and Hibernate and Spring Data JPA have become industry standards.

Main Difference

ORM is a technique for querying and manipulating data in a database using the object-oriented paradigm. It allows developers to work with relational databases without writing SQL directly. Hibernate is a framework that provides the actual ORM implementation of JPA, while JPA is an API specification primarily focused on defining ORM standards.

Differences Between JPA and Hibernate

JPA defines in javax.persistence package but hibernate describes in org.hibernate package.
JPA is java specification but hibernate is a framework.
JPA use JPQL to execute database operations where hibernate uses HQL.
JPA provides the EntityManager interface to create, read, update, and remove operations on instances of mapped entity classes, whereas Hibernate uses the Session interface for the same purpose.

Conclsion

JPA is a specification that defines ORM standards, while Hibernate is a framework that implements those standards. In Spring Boot applications, Spring Data JPA uses JPA as an abstraction, and Hibernate usually works behind the scenes as the ORM provider.

Understanding this difference helps developers choose the right approach and avoid common confusion.

Learning Through Contribution - Hacktoberfest 2025🎯

Hirushi Nethmini — Thu, 30 Oct 2025 13:42:06 +0000

This is a submission for the 2025 Hacktoberfest Writing Challenge: Contribution Chronicles

This year marks my first ever Hacktoberfest contribution. 🧩
As a software engineer, who's passionate about continuous learning I wanted to challenge myself by contributing open source. Last year I didn't participate, but I read several articles written by Hacktoberfest winners 2024. This year I didn't overthink, just participate with finding issues and enhancements.

First PR Accepted - Java Streams example with Real world scenario #46

Enhancement-1
The repository focuses on Advance Java Programs. While reviewing it, I found many concept-based examples that were quite useful. It reminded me of a real-world scenario I had come across while practicing Java Streams from an interview preparation book. At that time, I couldn’t fully solve it. I realized that adding this real-world example to the repository would provide additional value and help others learn Java Streams more effectively.

Second PR Accepted - Product Analysis using java streams #76

Enhancement-2
While exploring the repositories which are labeled as Hacktoberfest. I found this repo focuses on Java Programs. I noticed it had many great Java examples but lacked one demonstrating the combined use of Streams and Maps. So, I decided to contribute an example on this topic. My PR Product Analysis using Java Streams adds a program that simulates a store and uses Java Streams and Maps to count products in each category. It was appreciated by the maintainer with the feedback;

"This is a great submission! The program is clean, and highly efficient"

Third PR - Repository Excluded

This PR includes basic example to understand Abstraction in java. The maintainer merged the PR, but the repository excluded by the Hacktoberfest community.

Fourth PR - Add a Java solution for checking if two words are anagrams #96

Enhancement-3
I found a repository named code-contribution that contains many problems similar to those we solve on LeetCode and HackerRank. It reminded me of the problems I recently solved on HackerRank, so I decided to contribute one of them to the repository. It was great way to refresh my knowledge, and I was able to solve it even better this time before.

Final Thoughts

I’m really proud to have participated in Hacktoberfest this year! It was an amazing experience contributing to open-source projects, learning from the community, and improving my coding skills. I’m even happier to share that three of my pull requests were approved and officially recognized on the Hacktoberfest website. This achievement has boosted my confidence and inspired me to continue contributing to meaningful open-source initiatives in the future.

🌟 Join My Office Dashboard Project for Hacktoberfest 2025 — Perfect for Beginners!

Hirushi Nethmini — Mon, 13 Oct 2025 08:41:07 +0000

This is a submission for the 2025 Hacktoberfest Writing Challenge: Maintainer Spotlight

Hey Everyone,
I started building this office dashboard for Dev Community challenge, but I didn't get the chance to publish it.
So, I decided to open it for Hacktobefest 2025 - To collabrate, share knowledge and grow together.

💡 About the Project

Office dashboard is a clean and cute looking web app designed for team workspaces.

Employee greetings and daily highlights
To-do list and upcoming events
Stars of the month
Birthdays and reminders
Notifications and calendar view

⚙️ Tech Stack

Frontend - React
Backend - Node JS, MongoDB (Planned)
Tools - Github, VS Code

🌱 Who Can Join

Anyone who loves to learn from real world scenarios.
This project is beginner friendly, so even if you're new to react or open source you can easily contribute.

🤝 Purpose

The main goal of this project isn’t just to complete features — it’s to learn, experiment, and grow together.

Git Hub Repo - Click here for Repo

Let's learn & build together...

MongoDB - Relational to Document Model

Hirushi Nethmini — Thu, 28 Aug 2025 12:03:03 +0000

When I built my first MERN (MongoDB, Express, React, Node JS) project at university, I was only focus on making the app work that I did not pay attention on database design.

Later through this course offered by mongoDB, I realized that my design had lot of problems. That experience taught me to understand the relational model in NoSQL databases.

For the past two years, I've been working with relational databases and I haven't had the opportunity to work with mongoDB. So, That's why I believe this certification will help strengthen my skills.

Link to the batch

Optimistic Locking & Pessimistic Locking

Hirushi Nethmini — Mon, 14 Jul 2025 08:35:28 +0000

In Fintech domain, especially when handling transactions Optimistic Locking & Pessimistic Locking mechanisms play a pivotal role in ensuring data integrity and preventing concurrency issues.
So, I’m here to share my knowledge and insights on these two types of locking.

Let’ assume a scenario, I have a bank account with a balance of Rs. 5000. I can make payments through mobile banking application and debit card. I given my debit card to my mother to buy goods at home. Then, she went to the supermarket and came to pay Rs. 4500 for goods. At the same time, I pay my mobile phone bill which is Rs. 3000.
Then the two transactions happened at the same time.
Transaction 1 – Rs. 4500 – through debit card
Transaction 2 – Rs. 3000 – through mobile banking app
Account Balance – Rs. 5000.
If both transactions are completed, it leads to a drop of account balance below zero or data inconsistency.
The solution to this problem is to use locking. There are two types of locking mechanisms.

Pessimistic Locking
Optimistic Locking

Pessimistic Locking

It is a locking strategy when a transaction reads a record, it should be locked. Then other transactions cannot read or modify that record until the lock is released. This approach is used in high concurrency environments.

Types of Pessimistic Locks:

PESSIMISTIC_READ – Allows reading but it blocks writing.
PESSIMISTIC_WRITE – Blocks both reading and writing.
PESSIMISTIC_FORCE_INCREMENT – like PESSIMISTIC_WRITE but also increment the version number even if no changes made.

PESSIMISTIC_READ
PESSIMISTIC_READ is the locking strategy shared access which means all transactions can read the record but cannot modify it while the lock is held. It blocks the write operation.
@Lock(value = LockModeType.PESSIMISTIC_READ) Optional<AccountBalance> findById(Integer id);

PESSIMISTIC_WRITE
Transactions cannot do read write operation until the lock release. No transaction can perform read write operations until the current transaction finishes.
@Lock(value = LockModeType.PESSIMISTIC_WRITE) Optional<AccountBalance> findById(Integer id);

PESSIMISTIC_FORCE_INCREMENT
It is like PESSIMISTIC_WRITE, but the only one difference is it forces the version field of the entity to increment.
@Lock(value = LockModeType.PESSIMISTIC_FORCE_INCREMENT) Optional<AccountBalance> findById(Integer id);

Optimistic Locking

It allows multiple transactions to read and write data simultaneously, without holding locks.

Types of Optimistic Locks:

OPTIMISTIC
OPTIMISTIC_FORCE_INCREMENT

OPTIMISTIC
It increases the version number when a record changes.
@Lock(value = LockModeType.OPTIMISTIC) Optional<AccountBalance> findById(Integer id);

OPTIMISTIC_FORCE_INCREMENT
It increases the version number when transactions perform read or write operations.
@Lock(value = LockModeType.OPTIMISTIC_FORCE_INCREMENT) Optional<AccountBalance> findById(Integer id);

Gold badge in Java

Hirushi Nethmini — Mon, 23 Jun 2025 09:44:26 +0000

Happy to earn a Gold badge in Java from HackerRank! 🚀

Celebrations

Hirushi Nethmini — Thu, 19 Jun 2025 04:55:36 +0000

This is a submission for Frontend Challenge - June Celebrations, CSS Art: June Celebrations.

Inspiration

June is a month rich with celebrations that honor identity, history, love, and joy. In my CSS Art, I focused on three special occasions celebrated in June.

✊🏾 Two People Holding the Red, Black, and Green Flag – Juneteenth
A tribute to freedom and resilience. I illustrated two figures proudly holding the Pan-African flag—symbolizing sacrifice, identity, and hope. Juneteenth honors the past and celebrates the journey toward justice.

👨‍👧 Children with “Best Dad” Card – Father’s Day
A heartfelt tribute to my father—the man who set aside his own dreams to make mine possible. This day is a reminder of his silent strength, unwavering support, and the love behind every sacrifice.

🍩 Donut Rain – National Donut Day
A sweet, silly celebration of my favorite treat! After long days at work, I treat myself to a donut from the cozy café near my office. There’s something magical about those little moments of joy-and yes, in my dreams, donuts really do fall from the sky.

Demo

Check out this Pen I made!

Journey

Process
When the user clicks the “Celebrate the Donut Day” button, the page comes alive with a whimsical donut rain.

Learned Things
🌈 Gained awareness about key June celebrations.
🎨 Revisited and applied advanced CSS techniques.
🍩 Built an interactive effect using JavaScript functions.
🧠 Strengthened my HTML/CSS/JS integration skills for visual storytelling.

I hope to participate in more complex development challenges.

Friendship to Love

Hirushi Nethmini — Thu, 20 Feb 2025 07:46:04 +0000

This is a submission for Frontend Challenge - February Edition, CSS Art: February.

Inspiration

February is a month known for celebrating love and friendship. But sometimes, love begins with the simplest bond of companionship. In the icy world of winter, two penguins find warmth in each other's company. Their story reminds us that the strongest relationships often begin as the best friendships, making February a month not just of love, but of heartwarming beginnings.

Demo

Here, the two penguins are best friends, and I added an animation of snow falling. When the user clicks the button "Click Here to Celebrate LOVE", the penguins move toward each other with a popping heart, and all the snowflakes change into red hearts.

Public Link for Demo:

Git Hub Link for Code: https://github.com/hirushi1999/Feb_Challenge

Journey

I created all the penguins and elements using HTML and CSS. I had trouble designing the beard of the penguin boy and reviewed many resources for that. I also added animations.

I’m really proud of my art and creative writing skills. I hope to add a small animation of the two penguins walking in the near future.

Thank you for reading.

Seeking Guidance to Grow as a Software Engineer

Hirushi Nethmini — Wed, 15 Jan 2025 09:53:31 +0000

I have 1 year of experience as an Associate Software Engineer and a 6-month internship at my current company. During this time, I’ve worked with Java, JSP, React, and Angular, and have experience with databases like Oracle, MySQL, PostgreSQL, and SQL Server. I completed a Python course on edX and used Python for my final year research, focusing on machine learning.

To expand my skills, I’ve started two MERN stack projects to strengthen my knowledge. However, I feel uncertain about my expertise and want to build confidence in my technical abilities as I plan to transition to a new company this year.
I would love to hear from experienced developers:

What should I focus on to improve my skills and confidence?
Are there specific areas or technologies I should dive deeper into?
Any advice for standing out during job transitions? Thank you in advance for your valuable insights!

Reflecting on My Journey Through 2024 🌟

Hirushi Nethmini — Mon, 06 Jan 2025 03:09:29 +0000

This is a submission for the 2025 New Year Writing challenge: Retro’ing and Debugging 2024.

As 2024 comes to the end, I find myself looking back at a year filled with challenges, achievements, and countless lessons that shaped my growth as a professional and an individual. Here's my retrospective on the year that was:

🌱 Lessons Learned

Continuous Learning is Key:
As a full stack developer, I've worked with Java, React, MongoDB, Node JS, Relational databases and fintech solutions.I constantly challenge myself to explore new technologies, diving deeper into Java.
Adaptability Matters:
Working on React and Struts 2 projects simultaneously required me to quickly adapt to different frameworks and project domains. It enhances my problem solving and logical thiniking.
Collaboration Enhances Growth:
Working on team projects taught me the importance of team work and communication.

💪 Challenges Faced

Overcoming Technical Hurdles:
While working on projects in the office, I found things that need to develop after doing a research. Sometime it needed to be completed in limited timeframe. I worked hard those times and try to develop new features without bugs.
Self-Doubt
At times, I felt like I wasn't doing enough to grow. However it motivated me to further develop my skills.

🌟 Achievements that made 2024 Memorable

Professional Growth
I've completed one year of experience as software engineer in industry.
Personal Milestones
I completed my portfolio website, adding value beyond my own journey. I started developing a cake website and a POS system and I plan to complete it this year.

🚀 How 2024 Shaped My Growth

This year taught me resilience, adaptability, and the value of consistent effort. It reminded me to celebrate small wins and stay curious. As I step into 2025, I carry forward the lessons, challenges, and achievements that have made me stronger and more determined.

🎉 Exciting Research Throwback! 🎉

Hirushi Nethmini — Mon, 18 Nov 2024 05:26:01 +0000

Although I didn’t share this before, I’m excited to post about it now! Looking back, this experience was incredibly rewarding and full of lessons. It’s never too late to celebrate and express my gratitude.

Last year, I had the opportunity to publish my final year research project, "Utilizing Machine Learning for Forecasting Profitable Vegetable Crops and Land Use in Sri Lankan Agriculture" at the 7th SLAAI Conference 2023. I’m incredibly grateful to my research supervisor Dr. Chinthanie Weerakoon and lecturers in our department for their invaluable support and guidance throughout this journey. It was an incredibly fulfilling journey that deepened my understanding of machine learning algorithms.

🌟 Key Highlights:

This research gives solutions for selection of profitable vegetable crops, reduction of surplus vegetable stocks and minimization of product losses in specific vegetable varieties.
It aims to predict the most profitable vegetable crop and the corresponding land area required for cultivation.

💪 Challenges Faced :

Gathering data from multiple departments was challenging, as some records were handwritten, requiring significant effort to compile and organize.
Algorithm Selection: Identifying suitable machine learning algorithms to address specific problems in agriculture took careful evaluation and testing.

📚 Resources:
IEEE Published paper: [https://ieeexplore.ieee.org/document/10365011]

I’m excited to share this journey now and am open to connecting with fellow professionals who are passionate about this field. Let’s exchange ideas and explore how we can contribute to further advancements!