How can I derive a list of existing classes in a project?

Question

I want to be able to store an array of every class in my project. Is there a simple way to do it so it looks like this?

Class<?>[] classes = SomeClass.getClasses();

Thanks.

EDIT: Here's the code for the main class.

package game_engine.main;

public abstract class Main {
    public static void main(String[]args){
        //do something
    }
    protected abstract void start(GameSettings settings);
}

Could you give some insight as to why you need to do this? [XY Problem](http://xyproblem.info/) — 4castle, Dec 02 '16 at 01:28
Possible duplicate of [Can you find all classes in a package using reflection?](http://stackoverflow.com/q/520328/5221149) — Andreas, Dec 02 '16 at 01:29
I'm trying to create a game engine with with an extendable main class, and a non-static init method. — Java Noob, Dec 02 '16 at 01:32
And, "every class", doesn't include anything in the jdk (that would be insane). Just in the project (src folder). — Java Noob, Dec 02 '16 at 01:34
Based on your comment, you may want to [check out this Q&A](http://stackoverflow.com/questions/29424612/how-would-one-create-a-custom-jvm-launcher) — Dioxin, Dec 02 '16 at 01:48

score 0 · Answer 1 · answered Dec 02 '16 at 01:26

0

There is no simple way to do it, no. Doing this involves scanning the classpath, which is not doable in a portable way. Google's Guava has ClassPath, but it explicitly says to not use it for production-critial tasks.

answered Dec 02 '16 at 01:26

diesieben07

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score 0 · Answer 2 · answered Dec 02 '16 at 01:43

0

I can't make it done in one-line code. But this may also help:

//scan urls that contain 'my.package', include inputs starting with 'my.package', use the default scanners
Reflections reflections = new Reflections("my.package");

//or using ConfigurationBuilder
new Reflections(new ConfigurationBuilder()
 .setUrls(ClasspathHelper.forPackage("my.project.prefix"))
 .setScanners(new SubTypesScanner(), 
              new TypeAnnotationsScanner().filterResultsBy(optionalFilter), ...),
 .filterInputsBy(new FilterBuilder().includePackage("my.project.prefix"))
 ...);

Detail：https://github.com/ronmamo/reflections

answered Dec 02 '16 at 01:43

Dai Kaixian

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I've tried using reflections before, but it didn't clone from git, the classes weren't able to be imported and it intellij couldn't import it. How do I add a github repository to a project? – Java Noob Dec 02 '16 at 01:45
You are not using maven or gradle? – Dai Kaixian Dec 02 '16 at 01:53
https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html – Dai Kaixian Dec 02 '16 at 01:59
It‘s Maven in 5 Minutes. Another alternative is to build the sourcecode as a jar and then add the jar to the classpath. But using maven is a better way. – Dai Kaixian Dec 02 '16 at 02:01
Okay. Thanks. I'll try it. – Java Noob Dec 02 '16 at 02:24
Hello, have you fix it? – Dai Kaixian Dec 02 '16 at 10:58

How can I derive a list of existing classes in a project?

2 Answers2