Re: Empty constants

Eric Sosman wrote:
Spud wrote:
I've just created a static class that contains a number of static, final, read-only, empty constants for common classes. For example, I've got:

public static final Map MAP = new EmptyMap();

where EmptyMap is a map implementation that has zero elements and throws an UnsupportedOperationException if you try to modify it.
[...]
Question: surely somebody, somewhere must be doing this already. Is there a standard class out there that everybody uses for this purpose? Maybe something in Apache Commons?

... or maybe something in java.util.Collections?
Like java.util.Collections.EMPTY_MAP, perhaps? See
also java.utilCollections.emptyMap(), which is a method
rather than a constant, but which plays nicely with
generics.


Perfect. That eliminates all Collections constants. Now I just have EMPTY_ITERATOR, empty Object arrays, and a few things like empty StringBuffers.
.

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