java - What does the dot operator `.` (before the generic parameter) mean? -

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i saw code today:

    immutablemap<class<? extends clientcommand>, commandprocessorinterface> immutablemap =             immutablemap.<class<? extends  clientcommand>, commandprocessorinterface>of(...

what syntax mean?

immutablemap.<class ..

i knew generics right after class name. no?

what difference between:

immutablemap<class.. , immutablemap.<class..

it means you're invoking generic static method, called of in immutablemap class.

it's pretty same you're invoking static method, nested in class:

someclass.staticmethod();

for cases when method has type-parameter defined, can explicitly provide generic type , done this:

someclass.<type>genericstaticmethod();

and answer final question:

what difference between immutablemap<class...> , immutablemap.<class... ?

the first used when creating instance of generic class. it's used define generic-type on class level, while second used invoke generic static method that's nested in class.


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