log4j2 strLookup

@Plugin(name = "thread", category = StrLookup.CATEGORY)
public class ThreadLookup implements StrLookup {
    @Override
    public String lookup(String key) {
        return Thread.currentThread().getName();
    }
    @Override
    public String lookup(LogEvent event, String key) {
        return event.getThreadName() == null ? Thread.currentThread().getName()
                : event.getThreadName();
    }
}