The best solution to dealing with user messages is the humble ResourceBundle. But even that is a pain. ATG provided a class called ResourceUtils, but it wasn't very Util. I lost count of the number of MY_BUNDLE_NAME and sResourceBundle fields I had to stick into classes to make everything work.

I wrote about this earlier, but I didn't think I had a good solution. Now I think I do.

public class UserMessages {
    protected UserMessages(String pBundleName) {
       mBundleName = pBundleName;
       mResourceBundle = ResourceUtils.getBundle(mBundleName);
   }

    public static UserMessages getUserMessages(Class pClass) {
       Package classPackage = pClass.getPackage();
       String name = classPackage.getName() + ".UserMessages";

       return getUserMessages(name);
   }


   public static UserMessages getUserMessages(String pBundleName) {
       return new UserMessages(pBundleName);
   }

   public String getUserMessage(String pCode) {
       String message = ResourceUtils.getUserMsgResource(pCode, getBundleName(), getResourceBundle());

       return message;
   }
}

Admittedly this is ATG-specific, but it's easy enough to generalize this.

Using this one class, you can do the following:

private static final UserMessages sMessages = UserMessages.getUserMessage(MyClass.class);

And from there you can get user messages for the package.

There's a number of optimizations possible with this class. I could make ResourceBundles hierarchical -- start at the class's package, and then go to each ancestor class and query for a valid messageCode. It should be possible to validate user messages through this class as well. I could do this by looking through the class and picking out any private String fields starting with "MSG_".

What I find interesting is that my instinct says that message code constants should be private to a class. I'm still not exactly sure why, but it just feels better to me if a class can't pick up parent message codes from a different package.