Java key - key map

I need开发者_高级运维 a kind of map which is accessible in two directions, so with a key-key structure instead of key-value. Does this exist in Java? If not, what is the best way to create it?

So example:

mySpecialHashMap.put("key1", "key2");

mySpecialMap.getL2R("key1") returns "key2";
mySpecialMap.getR2L("key2") returns "key1";

So you want a bidirectional map. You can use Apache Commons Collections BidiMap or Google Collections BiMap for this.

You might want to look at BiMap from the Guava library (formerly known as Google Collections).

An example where a HashBiMap is used as the "mySpecialHashMap":

BiMap<String, String> myBiMap = HashBiMap.create();
myBiMap.put("key1", "key2");

myBiMap.get("key1"); // returns "key2"
myBiMap.inverse().get("key2"); // returns "key1"

Yes, there is BiMap from Google Collections.

Or for reversible enums see this Stackoverflow question.