I am trying to develop an application in libGDX for iOS.
In my Java class I have written this line
private Texture texture = new Texture(Gdx.files.internal("data/folder_name_1/folder_name_2/abcd.png"));
com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load file: data/folder_name_1/folder_name_2/abcd.png
You've got the error right in front of you...
the resource you are looking for is NOT in the "data" folder. It's in the "Assets" which is in the android project.
Also when loading textures you don't need to use a FileHandler.. This would be enough:
texture = new Texture("image.png");
which would be the root (assets) folder of the android project