Today, I applied for Fresher Backend Engineer which uses Java as programmer language. Although I know nothing about Java, I told a recruiter that I know it. So, I have 2 days to learn Java core until the interview. I have experience in Python, Javascript (Reactjs, Express.js), Typescript. Can you tell me which is most important thing in core Java ? What should the interviewer expect fresher Java candidate ?

I want to include the following Key features:

1. User Chats & Chat Rooms: Users can chat directly or in rooms.

2. Persistent Messages: Messages are stored and retained.

3. Containerization: Planning to containerize and host the app.

Questions

1. Should I create a REST API to get data on all rooms a user has joined?

2. Should I also create REST API to fetch message history in a room?

3. Is PostgreSQL a good choice for storing chat messages?

4. Any open-source chat apps I can study for reference?

If i am assuming/doing something wrong ... please point me to a right direction

I googled to see some examples but all i see is a basic app with only one room/topic

Thank you for your time

Hello guys, I am interested in learning Java, I am a computer science student, any recommendation for a good book to complement my course?

Hey everyone, I want to learn Java development but I don't how to start and where to learn.

I have asked similar questions to "can packets be read using java" in the past and very recently. Every time I do this people scatter, or get defensive attacking the reasons why I want to do so. I never actually end up getting any help, rather people telling me to change language without providing reason. Have I stumbled onto a large secret that I seem to be outside the loop on, or do people get defensive because they do not know themselves? It seems to me that packet capture and analysis is a taboo among java developers for whatever reason.

Why do some not include public in it, like:

static void

why not add public?

what does public even mean?

That word just irritates me in general

RunsPrinter.java

public class RunsPrinter {

FUCKIN ERROR

I have an array of integers and need to replace some of them with strings of text. All my attempts have been in vain.

int [] myArray = {0, 1, 2, 3, 4};

myArray[0] = "string";

This method works for other integers but not for strings. Is it because the array can only ever contain integers? Is there a way around this? My quick googling hasn't answered my question so I just thought I'd ask here. Thanks for any help! :)

So i am sorta beginner in java so i was some issue n couldn't figure out the issue so cursor helped me out with it, so i was wondering what level of experience in java would be able to figure out the issue, in plain words how much experience shld be able to figure out the below issue without cursor or ai tools

The issue was: The file has a UTF-8 BOM (Byte Order Mark) at the beginning. PowerShell's Get-Content -Raw and ReadAllText automatically strip the BOM when reading, so they don't count it. Java's InputStreamReader was counting the BOM as a character (U+FEFF), which caused the 1-character difference. The fix: The code now checks if the first character is the BOM (0xFEFF) and skips it, matching PowerShell's behavior. Character counts now match between Java and PowerShell.

Hi everyone, I am 27 years old now and I just recently dropped out of university without any degree due to illness and personal issues.

I am now trying to find a spot for an apprenticeship in app development but I lack enough skill to apply so I was wondering where to start in order to build a small portfolio.

I know a little bit of java but to be honest, I did not manage to understand more than the concepts in university. I have some practise but till today I don't even understand what the string [] args in the main function does nor do I have any clue how compilers and interpreters work not even wanting to speak of having build any application yet.

I have some ideas for some small tools like writing a script that tells you the weekday after entering a date or building a small website for the purpose building a portfolio but I realized that I got too reliant on GPT and AI to "understand" things so now I am here to get some advice on learning how to become a sufficient programmer.

Should I read books or just practise until I get a grasp on how things work?

Is it enough to google and learn by doing or should I do some courses/ solve problems on websites like leetcode?

When should I ask GPT for help? I have asked GPT to help me with a script before and I can't remember anything I did, all I know is that the script worked out and I feel like I betrayed myself.

I don't know what to do, I will try to start and find some direction and reddit and github/stackoverflow but since I could not pass Math in high school I am in doubt. (My prof was a foreigner that did not really explain a lot but just kinda copy pasted the whole lecture (which he did not write by himself) but that's my excuse for now.)

Thanks for reading and I am grateful for any response. Thank you.

So I'm learning java for 3 months now, even made a few simple projects, though my friend is telling me that java might lose to something like dart and its framework flutter, I read a little bit about it, but Im unable to get a conclusion if he is right, if someone has experince in that, please tell me your opinion

Jre does not exist anymore... so i have to build myself with Jlink... but i can't possibly build for all platforms, i got only linux. I can't distribute a jar and hope for the customer to get a JRE. So what do i do? The JDK is too large for a client to download just for one app..

Is there any cross platfom solution?

A situation where you go like: "oh, yeah, Java would be perfect here, no other language would do it better" as I find it quite difficult to find such situations. As the main selling point of Java is it is cross-platform, but also other languages like python, go, C# and more are nowadays.

I mean:

• concurrency-bases apps -> Golang

• networking -> Golang

• simple scripts running server side -> Python/Bash

• performance critical applications -> C

• security on the memory level -> Rust

• most web stuff -> Javascript/Typescript

• quick development and testing -> Python

I find Java a pain to distribute even if you install the JRE on the client, as sometimes you have to ship the EXACT development JRE used to make the app in the first place.

I have known and used java for about 4y now, but every time I think of building something I don't even consider it as a good option instead of something else.

Hey everyone.
I am a computer science student, and I must start coding with Java.

I tried Eclipse and netbeans but none were valid on my machine.
so if someone has an alternate IDE I will much appreciated.

Yeah

I am 12 years old and I have worked with java a few times.

I have two problems I need help with. One No matter What I set the icon as, when I open the app it shows this.

Also the title always says application at the top of screen (Mac). The app is named averager.

If you can help please comment.

im in university (a+ grades ) in computer science division and just got in forth semester and right now i can already solve leetcode medium level problems in 30 mins at average ,how much time it can take for me to reach a skill where i can be lavelled "expert" class in java related development and what would the best resources to get their be like books,online resources etc?

I am just curious: Can't they just set a breakpoint and check it out for themselves?

Seems a lot more obvious than posting your code online asking strangers for help, since all that needs to be done is set watches on the variables in question, set a breakpoint and you're done.

It just seems counterintuitive, which is why i am asking.

i made this code,its supposedly a code where it calculates the radius,but the thing here is; I dont understand a single line of code i just wrote I was hoping someone could try and help me.

https://ibb.co/T4P7sq7

I am trying since past 2 years, I watch courses I learn languages but when it comes to make a simple very simple project I can't!!!! Please help me I want to be a very proficient java developer but I can't please please help me

Um I'm confused of what I'll use java for and the aim of why I'm using java, i guess im a beginner that's why im having this problems....buh if someone whats to be the best java developer, what are the steps, like a road map that applies in the real world to be the best cus I'm lost😭😭...please I need an advice and help