Say I need a data structure in Java involving one set of categories, each with one set of subcategories. For example, let’s say the main category is ‘brand’ (like, of a product) and the subcategory is ‘product’. I want to be able to map the combination of brand+product to a piece of data e.g. a price.
I’d like to use an enum type for both ‘brand’ and ‘product’ if they were on their own, because
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Brand+product has only a small, single piece of data tied to it (the price)
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I need to refer to them many times throughout a reasonably large program, so the chance that I’ll mistype any string literal keys I assign to them is basically one.
However, the number of brands/products is too large to have a single enum for each brand/product combination (around twenty brands each with ten products and a good chance of adding more later). I’d like to be able to use the structure like this:
getPrice(APPLE.IPOD)
getPrice(APPLE.MACBOOK)
getPrice(HERSHEYS.PEANUT_BUTTER_CUPS)
Should I use some sort of nested enum? If so, how would that be implemented?
Bonus information: I’ve spent a bit of time googling ‘java nested enum’ but haven’t come up with anything. The problem with structures like the first one in the ticked answer here or thelosts’s answer here is that I have too many categories all exhibiting the same behavior to write out very similar enum definitions so many times.
I wouldn’t use an enum for this.
I would suggest you load this information from a file or database. Java is not a good place for storing large amounts of data.