java - The type HashMap is not generic; it cannot be parameterized with arguments <String, Integer> -

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this strange error getting today when try implement map below. 

map<string, integer> cache = new hashmap<string, integer>();

i using jdk 1.7 , not sure why error has been coming , changing above line adding cast removes error. i looked @ related posts in stackoverflow before posting question seems strange issue.

map<string, integer> cache = (map<string, integer>) new hashmap();

check using java.util.hashmap , java.util.map in imports.


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