计算LinkedHashMap中的键<String,ArrayList <String >>

Question

假设我有这样的事情:

LinkedHashMap <String, ArrayList<String>> h 
keyOne has
stringOne 
stringTwo 
stringThree

keyTwo has
stringOne

如何计算关联键的ArrayList的大小？所以对于keyOne,它应该给我3.

Answer 1

你试过了吗:

ArrayList<String> tmp = h.get("keyOne");
if ( tmp != null ) {
    return tmp.size();
} else {
    return 0;
}