CODEWITHSUNDEEP
javaarrayslist
mobo
mobo

Reputation: 301

Creating an Array of Lists

Is there a way to combine Lists and Arrays in Java? I am storing data for a tile map in 2D arrays instead of 2D lists, because that way I can define a set size for them. Its worked so far because each location has a single tile and can only have a single object occupying it. Now I want to add multiple effects to a single tile, but Java does not allow creation of an Array with generics, so no ArrayList[][]. If each tile was its own object it could just have its own ArrayList of effects, but I really want to avoid that. Also I don't know how many effects each tile may have, so I cannot just define a 3D array.

Any suggestions about how to get around this. I would like more design oriented suggestions, instead of a hack to get around the array/generics issue.

Upvotes: 0

Views: 162

Answers (3)

卢声远 Shengyuan Lu
卢声远 Shengyuan Lu

Reputation: 32014

Powerful Guava Table (JavaDoc) can be used.

Upvotes: 1

duffymo
duffymo

Reputation: 309008

I think a more object-oriented approach would suit you better than complex, nested structures.

Encapsulate what you want into a single object that you can maintain in something simpler. I see your approach becoming obtuse and hard to follow rather quickly.

You could maintain a single List of sparse entries if each one kept its (i, j) position in the grid along with its state.

Upvotes: 6

tom
tom

Reputation: 22989

The object-oriented way is to make each tile an object, but you say you really want to avoid that. You can use inheritance instead of composition if that's the problem:

class Effects extends ArrayList<Effect> { }

The alternative is to use an unchecked cast, which you also say you don't want:

ArrayList<Effect>[][] board = (ArrayList<Effect>[][]) new ArrayList[...][...];

Upvotes: 1

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