Where's my flaw in this crafting system?

I'm not very good at debugging and haven't been with java for long enough to see any errors.
So, how I'm making my crafting system is in four steps:

1) I test if the player is in a crafting block with

if(!Crafting.isOpen())
    return;

2) If that is true then I test if the player has specific items with

if(inventoryItems.contains(//certain item) && inventoryItems.contains(// certain item) {
    g.fillRect(100, 100, 100, 20);
    g.setColor(Color.white);
    g.drawString("Craft " + // certain item, 110, 111);
} else 
    return;

3) If all of that is true I test if the mouse touches the craft "button" with

if(Mouse.MouseX() >= 100 && Mouse.MouseX() <= 200 && Mouse.MouseY() >= 100 & Mouse.MouseY() <= 120) {
    inventoryItems.add(// certain item);
}

I feel like step 2 is wrong, but I can't find any error; also, is there any alternative to .contains();?