Code not running (javafx)

[proven kiln]

First of all, this is a simple side scroller beatemup game. It's just supposed to be a simple project that uses javafx. it wont boot up properly. I don't know how to explain the issue because this has to do with the setting up of the environment rather than the actual code not working I believe.

im getting errors such as

exception in Application start method.
and a larger wall of text following with many different errors that, once again, seem to be not errors with the code itself

(for the record, my project partner was the one who created it. I'm just attempting to get it set up for myself. They are also having issues with it.)

I dont know how to explain the problem further.

[modern adder]

<@&987246487241105418> please have a look, thanks.

[quiet robin]

It would be helpful sharing the full error

also are you using maven or gradle?

it may be helpful sharing the build settings as well

[proven kiln]

Exception in Application start method
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:118)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at [email protected]/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
at [email protected]/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1149)
Caused by: java.lang.RuntimeException: Exception in Application start method
at [email protected]/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:893)
at [email protected]/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:196)
at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.Error: Unresolved compilation problem:
MainGameApp cannot be resolved

    at beatemup.GameManager.<init>(GameManager.java:148)
    at beatemup.Main.start(Main.java:11)
    at [email protected]/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:839)
    at [email protected]/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:483)
    at [email protected]/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:456)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
    at [email protected]/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:455)
    at [email protected]/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at [email protected]/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at [email protected]/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:185)
    ... 1 more

Exception running application beatemup.Main

oops

uh, that's the error im getting

[quiet robin]

Caused by: java.lang.Error: Unresolved compilation problem:
        MainGameApp cannot be resolved

        at beatemup.GameManager.<init>(GameManager.java:148)
        at beatemup.Main.start(Main.java:11)

this kinda shows that the error seems to be in your code

please share Main and GameManager

or at least the relevant sections

[proven kiln]

ok one sec. btw, what's that thing that formats code here in discord

like what are the symbols

[modern adder]

Please use this format for posting code:

```java
// Example java program
int value = 5;
System.out.println(value);
```

Which results in:

// Example java program
int value = 5;
System.out.println(value);

For syntax highlighting, you have to add the name of the language after the three backticks, like ```java. Please make sure to use exactly this format, so no space between the backticks and the language name, and a newline before the code starts. If done right, the syntax highlighting will even be applied to your text as you type, before sending.

squidxtv • used /tag id: code · May 8, 2025, 5:42 AM

[quiet robin]

this explains it

[proven kiln]

ah thanks

MAIN:

package beatemup;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) {
        GameManager gameManager = new GameManager();
        Pane root = gameManager.getGamePane();
        Scene scene = new Scene(root, 800, 600);
        primaryStage.setTitle("Beat 'Em Up Survival");
        primaryStage.setScene(scene);
        primaryStage.show();
        gameManager.startGameLoop();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

[modern adder]

Detected code, here are some useful tools:

[WARNING] The code couldn't end properly...

Problematic source code:

package beatemup;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) {
        GameManager gameManager = new GameManager();
        Pane root = gameManager.getGamePane();
        Scene scene = new Scene(root, 800, 600);
        primaryStage.setTitle("Beat 'Em Up Survival");
        primaryStage.setScene(scene);
        primaryStage.show();
        gameManager.startGameLoop();
    }

    public static void main(String[] args) {
        launch(args);
    }
}```
Cause:
The code doesn't compile:
illegal start of expression

## System out
[Nothing]

[modern adder]

I uploaded your attachments as Gist. This makes them more accessible, for example to mobile users.

[proven kiln]

the gamemanager's code is much too large

ill send the txt file though

[modern adder]

I uploaded your attachments as Gist. This makes them more accessible, for example to mobile users.

[proven kiln]

did i accidentally send the Main file like 5 times (or the gamemanager). Apologies. only two files are relevant

[quiet robin]

all good

so let me give you a walkthrough

[proven kiln]

yes please

[quiet robin]

You have this error, what information does it give you?

Caused by: java.lang.Error: Unresolved compilation problem:
        MainGameApp cannot be resolved
        at beatemup.GameManager.<init>(GameManager.java:148)
        at beatemup.Main.start(Main.java:11)

[proven kiln]

is it simply because I'm calling main incorrectly?

it isn't supposed to be MainGameApp but rather Main?

[quiet robin]

not necessarily, lets just stick to the reason first before trying to fix it

what is the reason for the error

and where is it located in your code

[proven kiln]

well, it's saying at 148, there is an error. it

148 in gamemanager

[quiet robin]

exactly

[proven kiln]

MainGameApp.setScene("start");

[quiet robin]

yep

do you know what this means then:

Caused by: java.lang.Error: Unresolved compilation problem:
        MainGameApp cannot be resolved

[proven kiln]

simply because it doesn't exist right?

not a class?

or file

or something

[quiet robin]

maybe
the reason is it doesnt know about the MainGameApp class that you are trying to use in that line

that can have many reasons

maybe missing import

maybe that file doesnt even exist etc

do you have a class MainGameApp?

[proven kiln]

no

these are all my files and I don't believe it exists anywhere

[quiet robin]

then why are you trying to use it?

[proven kiln]

it was my project partner who did most of the code. I just believed in them since they took lead of the project

[quiet robin]

hm fair

then it makes sense to ask them

[proven kiln]

i shall do that right now but the current fix sounds like changing the MainGameApp into Main probably right? I can only assume that was the intent anyways

[quiet robin]

well as you said, its just an assumption (which is probably wrong)

it tries to use a static method setScene and Main doesnt have that

so it wont work either

[proven kiln]

i see

I am pretty sure this guy fell asleep after giving me his debugging work. how annoying

[quiet robin]

lol

[proven kiln]

i believe the method setScene doesn't exist

[quiet robin]

try a search all

but it might even be intented if this is group work

[proven kiln]

i see

[quiet robin]

maybe he wants you (or someone else) to create that class and implement that functionality

[proven kiln]

wait, maybe he just made a simple mistake of, in game manager, using setScene instead of getScene?

actually

that's probably wrong

[quiet robin]

I doubt that, but best thing would be asking the person about the intent

[proven kiln]

He wasn't asleep in the end but he just says, "I must've imss spelled it or I didn't check very well what I was typing in for the code."

I think bro chat gpt'd this. I dont think this guy knows what's going on whatsoever.

[quiet robin]

yeah, so did he even tried the code?

[proven kiln]

I feel like accidentally using an incorrect class like that or just a wrong name is very chatgpt to do

[proven kiln]

he says he was also having issues setting up the environment. says he was using java 24 but

idk

[quiet robin]

seems like you arent using a build tool, which would be the first mistake in a group project

[proven kiln]

It sucks cause I was working on code before that ACTUALLY ran (despite it not looking very nice)
but he offered to do the code while I did the presentation

[proven kiln]

as in something like screen builder? or what exactly are you referring to

[quiet robin]

nah

it helps setting up your project and working in basically every environment

like you are using vsc and imagine someone else using intellij

but build tools do a lot more

and are complex, you probably didnt learn them yet

[proven kiln]

i think i may understand

[quiet robin]

which makes it harder to do group projects though

[proven kiln]

yeah they didn't teach us to do javafx or anything else

just the basics and they want a project on it

dunno

[quiet robin]

these might be helpful

[modern adder]

JavaFX Tutorials

Official Documentation

• Project Setup: https://openjfx.io/openjfx-docs/
• API JavaDocs: https://openjfx.io/javadoc/23/
• Introduction to FXML: https://openjfx.io/javadoc/23/javafx.fxml/javafx/fxml/doc-files/introduction_to_fxml.html
• CSS Reference: https://openjfx.io/javadoc/23/javafx.graphics/javafx/scene/doc-files/cssref.html

Community & Tutorials

• FXDocs: https://fxdocs.github.io/docs/html5/
• Jenkov Tutorials: https://jenkov.com/tutorials/javafx/index.html
• Fundamentals (dev.java): https://dev.java/learn/javafx/

Additional Tools:

• Scene Builder: https://gluonhq.com/products/scene-builder/

squidxtv • used /tag id: javafx-tutorials · May 8, 2025, 6:10 AM

[proven kiln]

do you think it's feasible to set up another file and transferring everything?

also, what are the version differences between 24 and 21

like, do the functions change name

i am thinking of changing from 24 to 21 simply because I had it working on my previous project

[quiet robin]

your version shouldnt matter too much

why do you want java 21?

[maiden cloak]

Java is a backwards compatible language, and JavaFX wise there are no major changes you should be impacted by.

[proven kiln]

im thinking irrationally. a bit stressed from the situation. I really do think my project partner has gone to sleep this time (it is 3am almost) and im basically alone in this at this point

I am ok now but i was just grasping at straws trying to get see if there was a simple fix that just somehow fixes everything

[proven kiln]

i see. thanks

[quiet robin]

why are you still awake lol
go to sleep and continue tomorrow

[proven kiln]

i would very much rather but im currently trying to get us out of this hole