Your String
s seem very related, since you have a use case that needs to randomly choose one among them. Therefore, they should probably be gathered in an array anyway (on a semantic point of view).
There won't be more "runtime filling" than with your current multiple fields:
public final class MyStrings {
public static final String[] strings = {
"this is string one",
"this is string two",
"this is string three",
"this is string four",
"this is string five"
};
}
Then you can pick one String
randomly this way:
Random random = new Random();
String randomString = strings[random.nextInt(strings.length)]);