使用Java在LinkedHashMap中按值获取密钥

Question

I have a big LinkedHashMap<Integer,<List<String>>

.

For example:

<86, ["abc","def","xyz"]>  
<32, ["ugy","oop","bbb"]>  
<..., ...........]>

What i want is when user type a Comma separated String(eg "abc,oop,bbb" ), i want to print out the key. In these case keys are 86,32,32 . I can handle separete the String into an array by using .split(" "); but i don't know what is simplest way to search these Strings ?

Answer 1

I would use a map of integers to sets, not lists, since using a set would make checking against the user input without regard to order relatively easy. Doing the same check for a list would be harder.

public Integer getKey(Map<Integer, Set<String>> map, String input) {
    String[] parts = input.split(",");
    for (Map.Entry<Integer, Set<String>> entry : map.entrySet()) {
        Integer key = entry.getKey();
        Set<String> value = entry.getValue();
        if (value.size() != parts.length) {
            continue;
        }
        int counter = 0;
        for (String part : parts) {
            if (value.contains(part)) {
                ++counter;
            }
            else {
                break;
            }
        }
        if (counter == value.size()) {
            return key;
        }
    }

    return null;
}