New to Java

I wanted to know if there is any Collection object which allows me to store multiple values for a key.

I have the data:

key "a" - value "0"
key "a" - value "1"
key "a" - value "2"
key "b" - value "3"
key "b" - value "4"
key "c" - value "5"

Is there some collection object where I can store the above data which includes duplication of keys?