[
https://issues.apache.org/jira/browse/LANG-536?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14174087#comment-14174087
]
Duncan Jones commented on LANG-536:
-----------------------------------
bq. The only point of note is that not all wrapper class contain a
compare(prim, prim) method in Java 6 so some logic will need to be reversed
engineered from Java 7. These could be made public for more general use.
Are you sure? Looking at
http://docs.oracle.com/javase/6/docs/api/java/lang/Comparable.html, it seems
like all the primitive wrapper objects implement this. Which ones do you think
are missing?
So, if we're going to go down the primitive route, do you want to do the
honours? Otherwise I'll adjust your first patch so that the primitive methods
look like the one in [my earlier
comment|https://issues.apache.org/jira/browse/LANG-536?focusedCommentId=14172305&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14172305].
> Add isSorted() to ArrayUtils
> ----------------------------
>
> Key: LANG-536
> URL: https://issues.apache.org/jira/browse/LANG-536
> Project: Commons Lang
> Issue Type: New Feature
> Components: lang.*
> Reporter: Sergei Ivanov
> Priority: Minor
> Fix For: Review Patch
>
> Attachments: LANG-536.patch, perftest.zip
>
>
> In my unit tests I often need to verify that an array is correctly sorted.
> In order to achieve this, I've got two helper methods as follows.
> Is it possible to integrate these methods into ArrayUtils?
> {code}
> /**
> * Checks that the specified array of objects is in an ascending order
> * according to the specified comparator. All elements in the array must
> be
> * <i>mutually comparable</i> by the specified comparator (that is,
> * <tt>c.compare(e1, e2)</tt> must not throw a <tt>ClassCastException</tt>
> * for any elements <tt>e1</tt> and <tt>e2</tt> in the array).
> *
> * @param a the array to be checked.
> * @param c the comparator to determine the order of the array. A
> * <tt>null</tt> value indicates that the elements'
> * {@linkplain Comparable natural ordering} should be used.
> * @return {@code true}, if the array is sorted; {@code false}, otherwise.
> * @throws ClassCastException if the array contains elements that are
> * not <i>mutually comparable</i> using the specified comparator.
> */
> public static <T> boolean isSorted(final T[] a, final Comparator<? super
> T> c) {
> if (a.length <= 1) {
> // Empty or singleton arrays are always sorted
> return true;
> }
> // Otherwise, check that every element is not smaller than the
> previous
> T previous = a[0];
> for (int i = 1, n = a.length; i < n; i++) {
> final T current = a[i];
> if (c.compare(previous, current) > 0) {
> return false;
> }
> previous = current;
> }
> return true;
> }
> /**
> * Checks that the specified array of objects is in an ascending order,
> * according to the {@linkplain Comparable natural ordering} of its
> elements.
> * All elements in the array must implement the {@link Comparable}
> interface.
> * Furthermore, all elements in the array must be <i>mutually
> comparable</i>
> * (that is, <tt>e1.compareTo(e2)</tt> must not throw a
> <tt>ClassCastException</tt>
> * for any elements <tt>e1</tt> and <tt>e2</tt> in the array).
> *
> * @param a the array to be checked.
> * @return {@code true}, if the array is sorted; {@code false}, otherwise.
> * @throws ClassCastException if the array contains elements that are not
> * <i>mutually comparable</i> (for example, strings and integers).
> */
> @SuppressWarnings({"unchecked"})
> public static <T> boolean isSorted(final T[] a) {
> if (a.length <= 1) {
> // Empty or singleton arrays are always sorted
> return true;
> }
> // Otherwise, check that every element is not smaller than the
> previous
> T previous = a[0];
> for (int i = 1, n = a.length; i < n; i++) {
> final T current = a[i];
> if (((Comparable<? super T>) previous).compareTo(previous) > 0) {
> return false;
> }
> previous = current;
> }
> return true;
> }
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
