for example:

public static LinkedList ll = new LinkedList;

解决方案

from your question, I think (not 100% sure) you are looking for

java.util.LinkedHashMap

in your case, it would be LinkedHashMap

from java doc:

Hash table and linked list implementation of the Map interface, with

predictable iteration order. This implementation differs from HashMap

in that it maintains a doubly-linked list running through all of its

entries.

if you do want to get element by list.get(5), you could :

LinkedList>

so you can get Entry element by Entry entry = list.get(5), then entry.getKey() gives you the STring, and entry.getValue() gives you the Double.