getClass().getResource() in static context

Question

I'm trying to get a resource (image.png, in the same package as this code) from a static method using this code:

import java.net.*;

public class StaticResource {

    public static void main(String[] args) {
        URL u = StaticResource.class.getClass().getResource("image.png");
        System.out.println(u);
    }

}

The output is just 'null'

I've also tried StaticResource.class.getClass().getClassLoader().getResource("image.png"); , it throws a NullPointerException

I've seen other solutions where this works, what am I doing wrong?

Brogue

What error are you getting? Are you sure you have the image in the classpath? – Crocket

ClassName.class is exactly the same as SomeClassReference.getClass(). You are getting the class of the StaticResource class. – Devries

@Crocket it either outputs null or throws a NullPointerException – Brogue

Don't use in this way. Why are using getClassLoader()? Simply use StaticResource.class.getResource("image.png") – Illegitimate

Always try to place the resources outside the JAVA code to make it more manageable and reusable by other package's class. – Illegitimate

Answer 1

Remove the ".getClass()" part. Just use

URL u = StaticResource.class.getResource("image.png");

Jamijamie

+1 X.class.getClass() is always going to be the Class class as all Classes have a type of Class As this is loaded by the boot loader, it almost never has the resource you want. ;) – Paget

Answer 2

Always try to place the resources outside the JAVA code to make it more manageable and reusable by other package's class.

You can try any one

// Read from same package 
URL url = StaticResource.class.getResource("c.png");

// Read from same package 
InputStream in = StaticResource.class.getResourceAsStream("c.png");

// Read from absolute path
File file = new File("E:/SOFTWARE/TrainPIS/res/drawable/c.png");

// Read from images folder parallel to src in your project
File file = new File("images/c.jpg");

// Read from src/images folder
URL url = StaticResource.class.getResource("/images/c.png")

// Read from src/images folder
InputStream in = StaticResource.class.getResourceAsStream("/images/c.png")

Illegitimate

I don't get the last 3 - they seem to make assumptions on the structure of some project, which may (or rather may not) apply to someone else's setup. – Fanniefannin

I want to try to keep resources outside the packages. – Illegitimate

just create the images folder to place all the images inside this folder. – Illegitimate