我在Google中寻找代码段，最终得到了一个解决方案...并且所采用的模式与以前的注释所引用的模式相同. 给我解决方案的代码是:

Looking for pieces of code in Google I ended up with a solution... And was applying the same pattern that previous comments refer. The code that gave me the solution was:

label.setIcon(new javax.swing.ImageIcon(getClass().getResource("/resources/gray.png")))

然后，我制作了要实现的方法:

With that, I made then the method that I wanted to implement:

private static void DisplayImage(JPanel jp, String url) {
    JLabel jl=new JLabel();
    jl.setIcon(new javax.swing.ImageIcon(getClass().getResource(url)));
    jp.add(jl);
}

也许这不是完美且最正确的解决方案，但对我来说却是完美的，这就是我想要的.

Maybe this is not the perfect and most-correct solution, but works perfect to my, that is what I want.

谢谢大家的回答和建议！

Thanks all for the answers and suggestions!