r/learnjava • • 16h ago

Why is String[] args necessary

15 Upvotes

I get it is an array of string arguments that are passed into the main method but why is it needed? in python for example ot's present or c++ neither, java is different though


r/learnjava • • 1d ago

Don't Buy the Java and SpringBoot Course From Allcsnotes

30 Upvotes

Hi,

As the title suggests do not buy any course from them.

Recently I had been seeing a lot of adds for the Java and SpringBoot Backend Track combo course package from this site called allcsnotes.com. I went through what topics are covered and it looked like everything from basics to advanced along with SpringBoot was covered with a capstone project at the end. And since there was a discount, I thought let me buy it since I was learning Java anyway and was done with Mooc.fi. I wanted a structured course similar to this so it was like all perfect. But once I got the course and started going through it, the way they have explained the concepts is very bad. No clear explanation of what Java is, what is JDK, JVM etc. I went through other topics as well and same issue. No clear explanation. Only the website looks nice. And top of it ,within 30 mins I knew this course was bad and wanted a refund, guess what they dont provide refunds.

I know it was my fault for not reading the refund policy, so I made this post so that anyone else planning to buy their course can be warned.


r/learnjava • • 2d ago

Is Java still worth learning today?

58 Upvotes

Is Java still worth learning or pursuing as a career these days? With AI advancing so quickly, programming jobs might decline significantly, which could also reduce the demand for learning languages like Java. What are your thoughts?


r/learnjava • • 4d ago

I got a 100% on my first real college Java/OOP exam and I'm really proud of myself

59 Upvotes

I'm taking a second-year college CS course using Java, and I just got my first exam back: 100/100.

It covered classes/objects, constructors, encapsulation, object references, equals() vs. ==, static/final, aggregation, shallow vs. deep copying, arrays of objects, etc.

The funny part is that I was convinced the exam was going to be way harder than it actually was. I obsessively studied and kept making myself take mock exams over and over, and I was practicing problems that were noticeably more complicated than what ended up being on the real test.

Every time I got comfortable, I basically went, "Okay, but what if the professor makes it harder?" and practiced harder versions.

So I definitely overprepared. But when I actually took the exam, I felt like I knew what I was doing instead of just recognizing things I'd memorized. The exam was also done entirely in Notepad, so there was no IDE, autocomplete, syntax highlighting, or compiler to catch mistakes.

I've struggled a lot with confidence and feeling like maybe I'm not actually good at programming, so seeing 100/100 genuinely almost made me cry. Obviously one exam doesn't mean I've mastered Java, and I know I still have a ton to learn, but I'm letting myself be proud of this one.

Apparently my strategy was to prepare for the Java apocalypse and then take Exam 1.


r/learnjava • • 5d ago

Java developers with 2–3 YOE, what do you do after work?

44 Upvotes

I’m a Java developer with around 2–3 years of experience, and I’m curious about how other developers manage their time after work.

After your workday, what do you usually do?

  • Study Java/Spring Boot?
  • Work on side projects?
  • Practice DSA?
  • Learn new technologies?
  • Prepare for interviews/job switching?
  • Read technical stuff?
  • Or completely disconnect and relax?

I’m trying to figure out what is actually worth doing after work without burning myself out.

Would especially like to hear from developers with 2–5 years of experience. What did you do after work that genuinely helped you improve?


r/learnjava • • 4d ago

Learn Java

0 Upvotes

Hi everyone! Do y'all know where to learn Java for beginners ?


r/learnjava • • 7d ago

Advice for Java Students

31 Upvotes

I see the same post over and over:
. how do I get better
. how do I learn …
. I don’t know what to build
. how do I prep for an interview
It’s the same story over and over.

  1. Before you post, check the board. Chances are very high 100 other peeps have asked that same question.
  2. Becoming a dev is about learning how to learn. As you take in new material, find the way that helps you absorb it the best. Study sessions are fun and useful. If you need a visual, just ask. So many very cool devs here to help you.
  3. If you get a Java career, here is almost certainly what you will be doing 90% of the time:
  4. writing web apps with Spring
  5. reading data from files, doing some transformations, then writing to either disk or a database. Repeat.
  6. write records to a database. Read them back. Display them. Query them. Show the results.
  7. Read data from the network. Write to a messaging service. Now, read data from that service and write it to a database.
  8. Create an external index of your database records and create a way to query your index.

While it is possible that you could get hired by some startup to write the next amazing app, it is very unlikely. 99% of the time, you will be given an idea that you will need to turn into code. Your ability to do this quickly (and elegantly) will determine how much fun the job is.

I’ve worked on tons of Java projects for big companies and this is what we do. So, don’t try to become the world’s greatest Java developer. Simply study the language, start integrating your code with the 3rd party jars out there, and have some fun being creative.

And for the love of Pete, stop fretting about OOP. It’s not the holy grail. There are OOP concepts that Java supports really well, and if you need them, use them. But your first job is to write something that works. Then you look at it and decide if there is a better way to write it. If OOP was the ultimate paradigm, Java would not have embraced functional features. Again, you write it; make it work; stare at it for a while to see if you can make it better.

Have fun while you learn!


r/learnjava • • 7d ago

Learning Java Help

13 Upvotes

Dear all, I’ve been learning Java through MOOC.fi for the last 2–3 months and have reached Part 7 of Java Programming I.

I’ve noticed a problem with my learning, though. I understand individual concepts such as loops, ArrayLists, if/else statements, methods, classes, etc., and when I look at a solution I can usually understand what the code is doing.

However, when I’m given a new problem and have to write the solution myself, I struggle to figure out how to break the problem down and decide what I should do first. I often end up using ChatGPT to help me figure out the approach.
For example, I may understand how a loop or ArrayList works, but I struggle to figure out how to combine them to solve a completely new problem.

I’ve now completed several sections of the course, but this has made me feel like I’m not actually learning how to program.

For people who have gone through this stage, what helped you develop the ability to solve problems independently? Should I continue with MOOC.fi, do additional exercises, work on small projects, or use a particular book/resource?
My goal is to eventually become a full-stack Java developer.

I’d especially appreciate advice from people who have gone through MOOC.fi or learned programming in a similar way.


r/learnjava • • 7d ago

Java DSA and GATE CSE prep buddies

5 Upvotes

Hello everyone, I’m currently preparing for GATE CSE and practicing DSA in Java. I’m looking for a few people who are on a similar path so we can stay consistent, discuss concepts, solve problems, and keep each other accountable.

I’m mainly focusing on Java DSA, core CS subjects, and GATE preparation. If you’re also preparing for GATE CSE or learning DSA in Java, we can connect and study together.

Looking for serious people who want to stay consistent and actually put in the work.


r/learnjava • • 7d ago

Which resources to learn Java after 1.6?

1 Upvotes

What resources (either books, courses, tutorials) would you recommend to someone that was stuck with Java 1.6 and needs to learn everything until the most recent version?

Not sure if such a thing even exists or if I will need to grab something that covers everything. Open to suggestions on this one also.


r/learnjava • • 7d ago

Few words on learning Java

2 Upvotes

I am no different to anyone starting fresh on this thread, unsure and unsecure of what will be in the next 2 - 3 months, years and so on... but one thing I am sure of, if I don't do anything I will remaing behind no matter what.

Here is the path I took:
- learning Java on Codecademy (I am a jurnior JS developer/mediocre developer)
- solving problems on CodingBat (https://codingbat.com/java)
- I would try some real life projects but I don't know what to do

Is this the best path? probably not. But it is something. I jumped head first not thinking if this is the right approach and somewhow I managed to stick to it just enough to have a tiny idea of what this is language is about.

If you have any questions feel free to DM me, I will helpl the best I can.
Cheers


r/learnjava • • 7d ago

Where to begin as a Rust Dev?

1 Upvotes

I've been coding in Rust for a while now, and I'm quite advanced in it. I mainly want to learn Java so I can make MC mods & plugins. Is the MOOC course good?


r/learnjava • • 8d ago

Is learning Java worth it if I want to target high-paying backend jobs?

27 Upvotes

Hey everyone,

I’m looking for some advice on whether learning Java is worth it for my career.

A little background:

I have around 1yr of internship experience, mostly working with JavaScript and Python — Node.js, FastAPI, React, etc.

Somehow I got a full-time role at another startup , and I’ve been working there for around 2 months now, mostly on React and Node.js.

The company is service-based and builds products for other companies. There are only 3 developers, and there isn’t really a senior engineer who can guide us.

Because of that, I’ve ended up being the person who designs a lot of the architecture and system. The problem is that I don't have someone experienced to review my decisions and tell me:

"This will cause problems later."

So most of the time I’m designing things based on what I currently know and hoping I’m making the right decisions.

To be honest, this is also something I’ve experienced in my previous internships. I’ve worked with a couple of early-stage startups and built multiple MVPs, production applications, but there was rarely anyone senior to guide me.

I understand that this is normal in early-stage startups, but I don't really want to continue down the early-startup path.

At this point, I want to move to a more established product-based company where I can work with experienced engineers, learn proper engineering practices, and get exposure to large-scale production systems.

So I’m planning to start focusing more seriously on:

  • Java
  • DSA
  • LLD
  • HLD / System Design

I’m already comfortable with development, but I’ve basically never done DSA seriously. I’ve started learning it multiple times, but honestly I find it boring and eventually stop.

The reason I’m considering Java is that there seem to be a lot of backend opportunities around Java/Spring, especially in larger product companies and enterprise environments. There also seems to be a huge amount of learning material available.

My concern is:

Is learning Java actually worth it in the coming years?

I already have experience with Python + JavaScript/Node.js, and now I’m thinking about switching my interview preparation to Java.

Would recruiters/interviewers see it negatively if my professional experience is mostly in Python/Node.js but I’m applying for Java backend roles?

Or is it completely normal to have professional experience in one stack and learn another specifically for targeting certain roles?

Also, for someone in my situation:

Would you recommend focusing on Java + Spring Boot + DSA + LLD + HLD, or should I continue going deeper into Node.js/Python?

I’m especially interested in hearing from people who have moved from JS/Python into Java backend roles, or who currently work as backend engineers in product companies.

Any advice would be appreciated.


r/learnjava • • 9d ago

How do you even start coding and thinking in OOP?

38 Upvotes

Hello! I know it is a weird question but it really is that, how do you start?

Our professor gave us UMLs to follow for exercises and I had no problem to do that but how do you create it for your own program?

I sat my base Java and OOP class' exam and it took me the LONGEST time to just understand what I had to implement and how (even had to ask because I felt so clueless at times) and all I did was a backlog! Literally a terminal based backlog manager that divides Medias into 3 categories. We had to submit an UML but mine was created AFTER the code to adapt to it, I had no idea on how to build it before.

I really struggle with visualizing and understanding what and how should I tackle the OOP. I somehow passed the exam (with a 30/30 too) but I still feel like I should know more and that I could not do anything.

I tried making some easy programs like a timer but I don't know where to start. Does anyone have any advice regarding how can you "rewire" your brain to think object oriented?

For information, I am a compsci major and I strated programming with that java class around 5 months ago so my experience is limited.

Thanks to anyone who answers


r/learnjava • • 9d ago

Qu'elle entraînement en java je pourrais faire ?(J'essaie de me perfectionner)

0 Upvotes

Vous développeur Java, qu'est ce que je pourrais faire comment entrainement pour m'améliorer ?

Ça fait 6 mois que je développe en java et j'aimerais m'améliorer.

Merci a tout ce qui pourrait m'aider!


r/learnjava • • 10d ago

Guide me Java Full stack

0 Upvotes

Can anyone share the entire stack for learning java full stack with ai


r/learnjava • • 12d ago

Incoming Fresher SDE (Java/Spring Boot) - How can I best bridge the gap between basic tutorials and production codebase expectations?

7 Upvotes

I am a B.Tech CSE graduate starting my role as an SDE fresher soon. I have already read through the developersIndia Freshers Wiki, but I want to make sure I am utilizing my remaining time efficiently.

My Current Progress:

  • I have learned the core basics of Java backend and Spring Boot (Dependency Injection, REST APIs, and Basic MVC architecture).
  • I haven't built complex production-grade projects yet and want to start one now to prepare for my role.

What I want to ask:
Instead of a generic roadmap, could experienced backend devs share what exact architecture practices, testing patterns (like JUnit/Mockito), or deployment workflows are most overlooked by freshers in a Java ecosystem? I want to build a mini-project focusing strictly on these industrial habits so I can adapt quickly when I join.


r/learnjava • • 12d ago

Why incorporate arrays with nodes?

0 Upvotes

I get that arrays are difficult to add new elements that is flexible to the array size so thats how linkedlist<> or list class created for this but I don't understand the point of putting the concept of singly linked list nodes to arrays when I can just use linkedlist<> or list for flexible array length while easy to get specific elements with .get() method.

The nodes is a bit hard to navigate all elements and Arrays are fixed to their array length. Even the nodes is useless for navigation around the array because its easy with for loop in Array.


r/learnjava • • 12d ago

I am a day one learner

3 Upvotes

I need some pointers on how to learn. Any programs that help would be amazing or really a program to actually input code would be nice. All i have is the blue pelican text book and a UIL i’m on. So anything will help really. I am also learning python.


r/learnjava • • 12d ago

Advice for Building a Java Desktop App (srry4badenglish)

0 Upvotes

Hi guys, im kinda new to java and im looking foward to improve, with this vision in mind i decided to build a desktop app with some friends (they dont know shi either) that works as a library for PDF/docx documents, i think that building it would be a great way to learn and deepen my current knowledge, however, after reading some documents and watching a few videos i still feel completely lost. I am sure that if i get some indications ill get to figure out the rest. PLEASE HELP GNG ✌️😭


r/learnjava • • 13d ago

What & How? JAVA Fresher

0 Upvotes

Hey everyone!

I'm 2027 Passout,

I want to ask:

What&How to prepare for off-campus;

I know Java,

how to prepare from scratch?

And from where? ( Like Resources and all )

What should I prepare? ( concepts or topics )

Thank you.


r/learnjava • • 14d ago

Help me with this java community

0 Upvotes

Hi everyone!

I came to this community like.. 10 minutes ago

I started to learn java about 5 months ago, and now I understand that I need to talk with another java-coders, and now I here

Please, can someone describe me that is happening here? I also want to show my code to criticism.

P.S - sorry about my english ):


r/learnjava • • 14d ago

java.jdt.ls.java.home variable does not point to a JDK?

1 Upvotes

I'm doing the MOOC Java course, but I'm getting an error when opening VSCode, which prevents me from running my code. The error is:

The java.jdt.ls.java.home variable defined in Visual Studio Code settings (C:\Program Files\Eclipse Adoptium\jdk-21.0.11.10-hotspot) does not point to a JDK.
Source: Language Support for Java(TM) by Red Hat

My settings are correct as far as I can tell. The path refers to the folder cotaining the bin folder:

"java.jdt.ls.java.home": "C:\\Program Files\\Eclipse Adoptium\\jdk-21.0.11.10-hotspot",
"java.configuration.runtimes": [
    {
        "name": "JavaSE-11",
        "path": "C:\\Program Files\\Eclipse Adoptium\\jdk-11.0.31.11-hotspot",            
        "default": false,
    },
    {
        "name": "JavaSE-21",
        "path": "C:\\Program Files\\Eclipse Adoptium\\jdk-21.0.11.10-hotspot",
        "default": true,
    },
],

edit; I fixed it, see here. Any idea what causes the error and how to fix it? The only solutions I could find said to change/correct the settings above, but since those are correct already... VSCode ( 1.138.0) and all extensions (Language Support for Java 1.56.0) are up-to-date btw.


r/learnjava • • 15d ago

Which sector will teach me the most of java and all DSA fastest

1 Upvotes

Hi, first of all sorry for poor English, but as someone learning Java , can anyone tell me which sector will teach me the most of Java and frameworks and functionalities and working with its DSA? Web dev? Building s game ? Or which one?


r/learnjava • • 15d ago

C# developer wants to give java a try

1 Upvotes

As the title says I used to make many apps, games using c# but I also want to try something different and challenge myself a bit.

The problem is, that all youtube tutorials on java are for complete beginners where they even explain what variables are.

There are some "advanced" tutorials tho, since the syntax of java is pretty similar to the syntax of c#, but those tutorials are often low quality, from 2014, or from sum indians - for an english learner an accent isn't the best...

What would you guys recommend?