Help matching fields between two classes

Question

I\'m not too experienced with Java yet, and I\'m hoping someone can steer me in the right direction because right now I feel like I\'m just beating my head against a wall...

Answer 1

You're probably better off using a Map rather than a List, you can use the enum as the key and get the values out.

Map<YourEnumType,ValueType> map = new HashMap<YourEnumType,ValueType>();

Answer 2

@Tom's recommendation to use Map is the preferred approach. Here's a trivial example that constructs such a Map for use by a static lookup() method.

private enum Season {

    WINTER, SPRING, SUMMER, FALL;
    private static Map<String, Season> map = new HashMap<String, Season>();
    static {
        for (Season s : Season.values()) {
            map.put(s.name(), s);
        }
    }

    public static Season lookup(String name) {
        return map.get(name);
    }
}

Note that every enum type has two implicitly declared static methods:

public static E[] values();
public static E valueOf(String name);

The values() method returns an array that is handy for constructing the Map. Alternatively, the array may be searched directly. The methods are implicit; they will appear in the javadoc of your enum when it is generated.

Addendum: As suggested by @Bert F, an EnumMap may be advantageous. See Effective Java Second Edition, Item 33: Use EnumMap instead of ordinal indexing, for a compelling example of using EnumMap to associate enums.