A utility class for issuing error messages. A user of this class normally would create a singleton instance of this class, passing the name of the message class on the constructor. For example: static Messages x = new Messages("org.package.MyMessages"); Later the message is typically generated this way if there are no substitution arguments: String msg = x.createMessage(org.package.MyMessages.KEY_ONE, null); If there are arguments substitutions then something like this: String filename = ...; String directory = ...; String msg = x.createMessage(org.package.MyMessages.KEY_TWO, new Object[] {filename, directory) ); The constructor of an instance of this class must be given the class name of a class that extends java.util.ListResourceBundle ("org.package.MyMessages" in the example above). The name should not have any language suffix which will be added automatically by this utility class. The message class ("org.package.MyMessages") must define the abstract method getContents() that is declared in its base class, for example: public Object[][] getContents() {return contents;} It is suggested that the message class expose its message keys like this: public static final String KEY_ONE = "KEY1"; public static final String KEY_TWO = "KEY2"; . . . and used through their names (KEY_ONE ...) rather than their values ("KEY1" ...). The field contents (returned by getContents() should be initialized something like this: public static final Object[][] contents = { { KEY_ONE, "Something has gone wrong!" }, { KEY_TWO, "The file ''{0}'' does not exist in directory ''{1}''." }, . . . { KEY_N, "Message N" } } Where that section of code with the KEY to Message mappings (where the message classes 'contents' field is initialized) can have the Message strings translated in an alternate language in a errorResourceClass with a language suffix. This class is not a public API, it is only public because it is used in com.sun.org.apache.xml.internal.serializer.