Java ImageIO.read(getClass().getResource()) returns null

Question

The line

andImg = ImageIO.read(getClass().getResource(\"gate_and.png\"));

fails with

Exception in thread \"AWT-EventQueue-         


        

Answer 1

Assuming your class is in package view.random.name, then

getClass().getResource("gate_and.png")

will look for the resource in

/view/random/name/gate_and.png

relative to the root of the classpath. You apparently don't have a resource by that name there.

By setting project/images as a build path entry, Eclipse will include everything in it on the classpath. Therefore, your resource will appear at

/gate_and.png

You can access it with

getClass().getResource("/gate_and.png")

Note the leading / that means start looking at the root of the classpath, ie. it's an absolute path.

All these rules are explained in the javadoc.