Getting all names in an enum as a String[]

Create a String[] array for the names and call the static values() method which returns all the enum values, then iterate over the values and populate the names array.

public static String[] names() {
    State[] states = values();
    String[] names = new String[states.length];

    for (int i = 0; i < states.length; i++) {
        names[i] = states[i].name();
    }

    return names;
}

Here's one-liner for any enum class:

public static String[] getNames(Class<? extends Enum<?>> e) {
    return Arrays.stream(e.getEnumConstants()).map(Enum::name).toArray(String[]::new);
}

Pre Java 8 is still a one-liner, albeit less elegant:

public static String[] getNames(Class<? extends Enum<?>> e) {
    return Arrays.toString(e.getEnumConstants()).replaceAll("^.|.$", "").split(", ");
}

That you would call like this:

String[] names = getNames(State.class); // any other enum class will work

If you just want something simple for a hard-coded enum class:

public static String[] names() {
    return Arrays.toString(State.values()).replaceAll("^.|.$", "").split(", ");
}

Here`s an elegant solution using Apache Commons Lang 3:

EnumUtils.getEnumList(State.class)

Although it returns a List, you can convert the list easily with list.toArray()

If you can use Java 8, this works nicely (alternative to Yura's suggestion, more efficient):

public static String[] names() {
    return Stream.of(State.values()).map(State::name).toArray(String[]::new);
}