What's your most reused class?

Question

Every programmer ends up with a set of utility classes after a while. Some of them are true programming pearls and they are reused in several of your projects. For example, in java:

 class Separator {

        private String separator;
        private boolean called;

        public Separator(String aSeparator) {
            separator = aSeparator;
            called = false;
        }

        @Override
        public String toString() {
            if (!called) {
                called = true;
                return "";
            } else {
                return separator;
            }
        }
    }

and:

public class JoinHelper {

    public static <T> String join(T... elements) {
        return joinArray(" ", elements);
    }

    public static <T> String join(String separator, T... elements) {
        return joinArray(separator, elements);
    }

    private static <T> String joinArray(String sep, T[] elements) {
        StringBuilder stringBuilder = new StringBuilder();
        Separator separator = new Separator(sep);

        for (T element : elements) {
           stringBuilder.append(separator).append(element);
        }

        return stringBuilder.toString();
    }
}

What is your most reused class?

Answer 1

Globals

Just a simple class with static DBConnString, and a few other app wide settings.

Have reused the simple file in about 2 dozen projects since working with .Net

Answer 2

A utility class that has logging and email functionality. An extensions class that contains extension methods. A reporting class that basically harness the reporting services web service and makes it easy to stream reports as excel, pdf, etc.

Examples...
1.) Utility Class (static)

   public static void LogError(Exception ex)
    {
        EventLog log = new EventLog();
        if (ex != null)
        {
            log.Source = ConfigurationManager.AppSettings["EventLog"].ToString();
            StringBuilder sErrorMessage = new StringBuilder();
            if (HttpContext.Current.Request != null && HttpContext.Current.Request.Url != null)
            {
                sErrorMessage.Append(HttpContext.Current.Request.Url.ToString() + System.Environment.NewLine);
            }
            sErrorMessage.Append(ex.ToString());
            log.WriteEntry(sErrorMessage.ToString(), EventLogEntryType.Error);
        }
    }

2.) Extensions Class

   public static IEnumerable<TSource> WhereIf<TSource>(this IEnumerable<TSource> source, bool condition, Func<TSource, bool> predicate)
    {
        if (condition)
            return source.Where(predicate);
        else
            return source;
    }

Answer 3

System.Object - almost all my types extend it.

Answer 4

Configuration Reader/Setter: which reads the configuration from ini/xml file and sets the environment of the application

Answer 5

Most reused? Hmmm...

boost::shared_ptr<> with boost::weak_ptr<>

probably most reused (also probably most bang-for-buck ratio)

Answer 6

A ConcurrentDictionary I wrote, which I now seem to use everywhere (I write lots of parallel programs)