Question

What I’m doing is storing classes into an ArrayList and retrieve them by its index number. But are there any list classes in Java where I can retrieve a list element by, lets say, its name? Like this:

ArrayList<string> myArr = new ArrayList<string>();
myArr.add( "ID_name", "String to store" );

ands then retrieve it by:

myArr.get( "ID_name" );

Also, are there any other alternatives to ArrayList? I need a list class to be optimized for:

• Random access
• Only need to push items into the list
• Never need to delete anything from the list

Answer 1

If all you want to store is key-value pairs, and don’t care about iteration order, I think you might like the HashMap class:

Map<String, String> map = new HashMap<String, String>();
map.put("foo", "bar");
String bar = map.get("foo"); // bar is "bar"