[Dev][Log4j2]Log4j2 converter for '@' is not working

[Chathura Priyankara]

Hi all,

I created following simple converter to append @ sign in to a log record,

@Plugin(name="AtSignPatternConverter", category = "Converter")
@ConverterKeys({"@"})
public class AtSignPatternConverter extends LogEventPatternConverter{

    protected AtSignPatternConverter(String name, String style) {
        super(name, style);
    }

    public static AtSignPatternConverter newInstance(String[] options){
        return new AtSignPatternConverter("@","@");
    }

    @Override
    public void format(LogEvent event, StringBuilder toAppendTo) {
        toAppendTo.append("@");
    }
}

However when I'm using %@ for conversion pattern. I'm getting following
exception.

2015-05-19 17:53:55,301 ERROR Unrecognized format specifier []
2015-05-19 17:53:55,302 ERROR Empty conversion specifier starting at
position 7 in conversion pattern.

(There are other some converters which are working fine in the same package
with this)

In log4j2 is it not allowed create converter for this symbol ?
can anyone please explain me why this is happening ?

Thanks,
Any help is highly appreciated.

-- 
Chathura Priyankara,
Faculty of Information Technology,
University of Moratuwa.