My motivation for the addition was for exactly one reason, writing null safe comparators.
The facility exists already in collections via ComparatorUtils.nullLowComparator(Comparator c) ComparatorUtils.nullHighComparator(Comparator c) I just failed to find it. -Antony On Tue, Aug 11, 2009 at 9:13 AM, Henri Yandell <flame...@gmail.com> wrote: > Maybe something for the CompareUtils class proposed in LANG-483: > > http://issues.apache.org/jira/browse/LANG-483 > > I'd prefer compareNullFirst, compareNullLast instead of the boolean param. > > Hen > > On Mon, Aug 10, 2009 at 5:23 AM, Antony Riley<ant...@cyberiantiger.org> > wrote: > > Maybe I'm missing something obvious but commons lang does not seem to > > provide a null safe compare method for comparable objects. > > > > My apologies if this functionality exists somewhere in commons lang and > I'm > > being brain dead with regards to locating it. > > > > It seems like a really obvious addition, code would probably look like > > > > // In ObjectUtils. > > > > /** > > * Compare two Comparable objects for order. > > * > > * This method is null safe. Null is considered to be less than all other > > objects. > > * > > * @param a the first object to be compared. > > * @param b the second object to be compared. > > * @return a negative integer, zero, or a positive integer as the first > > argument is less than, equal to, or greater than the second. > > */ > > public int compare(Comparable a, Comparable b) { > > return compare(a,b,true); > > } > > > > /** > > * Compare two Comparable objects for order. > > * > > * This method is null safe. Null is considered to be less than all other > > objects if nullfirst is true, else > > * it is considered to be greater than all other objects. > > * > > * @param a the first object to be compared. > > * @param b the second object to be compared. > > * @param nullfirst > > * @return a negative integer, zero, or a positive integer as the first > > argument is less than, equal to, or greater than the second. > > */ > > public int compare(Comparable a, Comparable b, boolean nullfirst) { > > // Deal with the case both a, b are null or they are both equal first. > > if (a == b) { > > return 0; > > } else if (a == null) { > > return nullfirst ? -1 : 1; > > } else if (b == null) { > > return nullfirst ? 1 : -1; > > } else { > > return a.compareTo(b); > > } > > } > > > > -Antony > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org > >
