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java-help

❓︱qotw-answers

Dev0Guy

10/3/2025

Maven With Java 25

Hello everyone! Im starting to learn java. I tried to configure maven to work with maven.compiler.release to be 25. However I keep getting errors. Any way one can provide example of pom file with java25? Thanks in advance !...

Mikaela Shipha

10/2/2025

Looking for java Swingset3

Hey guys, was wondering if anybody for love of god can guide or help me on where I can find this specific version of java Swingset3? https://docs.oracle.com/javase/tutorial/uiswing/lookandfeel/nimbus.html Above is the link to the picture the specific version I'm looking for, also provided image id nobody wants to open the link. PLEASE for the love of god if anybody knows where I can get it, specially along with it's source code so I can navigate in-app source code tabs as u can see in the pictures that would be a great help....

undoublethink

10/2/2025

Round trip reflective serialisation with exact type matching

I need to serialise lists of heterogeneous Objects. These lists represent arbitrary "lookups" into data. For example [John, 2000-01-01] when paired with a key like [name, dob] represents people named John born on 2000-01-01. These key and value lists are saved in a database and associated with other data. The difficulty is that at runtime I only have a List<Object> for the values. I can save this as JSON in the database but when pulling it out of the database number types will not map to the original type. JSON does not differentiate numerical values so eveything becomes double. I need the round trip to be identical so the objects generated by the application and those that are saved can be compared for equality. I'd be grateful for any possible solution. So far I've considered Message Pack, Cbor and custom encoders/decoders. I only need to handle most primitive types, dates, timestamps and a small selection of others. ...

Nevena

10/2/2025

How to connect Checkstyle JAR (v10.12.1) with VS Code

Hi everyone 👋 I downloaded Checkstyle JAR version 10.12.1 and the google_checks.xml file, but I can’t figure out how to connect the Checkstyle JAR with Visual Studio Code. Could someone please guide me step by step (what exactly I need to click/configure) to make it work? 🙏...

Potentiometer Annihilator

10/2/2025

JNI IllegalAccessError

I am using JNI to call some static Java method from Rust side, but its throwing an java.lang.IllegalAccessError exception the code for calling the method is nothing special: ```rs // 5. Start JVM...

valer

10/2/2025

Multithreading

When dealing with multiple threads, is it better to extend the Thread class or implement Runnable?

Mosahel Khanzadeh🌴

9/30/2025

Completed Java, 10 months left in final year — Feeling a bit lost, what should I focus on next?

Hi everyone, I’m currently in my final year of BTech, and I have around 10–11 months left before graduation. Recently, I completed learning Java (core + OOPs, etc.) from BroCode's 12hr YT tutorial, and I’m now trying to figure out what I should focus on next to make the most of this year.

A bit about my background:-

i have decent knowledge of frontend development (ReactJS)....

bambizas19

9/29/2025

Why am i getting error: generic array creation?

Hello everyone. I started doing codewars, and got stuck on the first task. Ive this: ```java public static List<Integer>[] arrayOfLists = new List<Integer>[] { Arrays.asList(1, 2, 3), Arrays.asList(4, 5, 6),...

valer

9/28/2025

Anonymous Classes

Hey guys, is anyone able to explain quickly an example of why you’d need to use an anonymous class?

sol

9/28/2025

redhat openjdk problem

please i need help i cannot figure out why i cant run a java file even though i have redhat openjdk installed on my linux

𝓖𝓾𝓻𝔀𝓲𝟑𝟎

9/27/2025

Create ErrorLens like plugin for IntelliJ

I wanted to create a ErrorLens (VSC Plugin) like plugin in IntelliJ, because every already available plugin is really slow and isn't customizable enough. But im not able to find any docs about how to do it and i can't really understand the already available plugins src because they are written in scala and im tring to write them in Java.

valer

9/27/2025

Lambda Expression

Guys I had a question regarding lambda expressions in Java, when the abstract method from the functional interface requires a parameter, is the parameter not mandatory to be inputted in the code block you pass into the abstract method?

𝒫𝓇𝒾𝓃𝒸ℯ𝓈𝓈 ♡

9/27/2025

Eclipse

I’m trying to install Eclipse, but this happens when I click on the app

SockyKun~ ;3

9/26/2025

Creating a QR based attendance system

Basically I want to make a cross platform wifi and Bluetooth based attendance system which generates a session ID and a random Qr code which contains the teachers wifi and Bluetooth connection requirements and marks the attendance

Lukas

9/25/2025

Map.get() Behaviour for objects with an equals() override

So my object is basically a few variables, which I compare in an equals() overridden method. When I my map contains an object like { myvar = 1; othervar = "Hello"; yetanother= 12.4f } and I map.get(new MyObject(1, "Hello", 12.4f) with an unrelated but content wise identical object, would it get the entry for the original object?...

Asdru

9/25/2025

Basic firebase login app with google that uses compose 2.0.0+

It there a template somewhere? i even looked at the android tutorial repo and theirs is outdated

Shano

9/25/2025

I just started Java and i already need help cuz im watching a tutorial and i cant write my first cod

Carnage

9/23/2025

I need help with this step

Lianecx

9/23/2025

Hotswapping with JBR and HotSwapAgent

hey, im trying to install the jetbrain runtime in a docker container along with hotswap agent. I am running on an arm ubuntu machine and tried the aarch JBR releases JCEF (fastdebug) and JBRSDK. I put the hotswap-agent.jar in lib/hotswap and i still get the error Unrecognized VM option 'AllowEnhancedClassRedefinition', im using java 21...

ZombieLab#0808

9/22/2025

**Need help for API 35 problem build problem in Unity game engine:**

I am trying to build my completed demo to the Play Store for Internal Testing. I am trying to do a aab build to my laptop to then Upload to the Google PlayStore for Internal Testing. My download keeps crashing to my laptop. The Console have these 4 errors in the screenshots (below) I downloaded Java-11 in the screenshot (below)...

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Java Community | Help. Code. Learn.

We are a Community full of Java developers. Connect with other devs, get help, help others and do much more!

Java Community | Help. Code. Learn.

We are a Community full of Java developers. Connect with other devs, get help, help others and do much more!