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https://issues.apache.org/jira/browse/COLLECTIONS-742?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17000714#comment-17000714
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Chen Guoping commented on COLLECTIONS-742:
------------------------------------------
Hello Wesllhey Holanda,
What about the CollectionUtils.get(Object object, int index) with index=0 ?
Line 1316:
{code:java}
/**
* Returns the {@code index}-th value in {@code object}, throwing
* {@code IndexOutOfBoundsException} if there is no such element or
* {@code IllegalArgumentException} if {@code object} is not an
* instance of one of the supported types.
* <p>
* The supported types, and associated semantics are:
* </p>
* <ul>
* <li> Map -- the value returned is the {@code Map.Entry} in position
* {@code index} in the map's {@code entrySet} iterator,
* if there is such an entry.</li>
* <li> List -- this method is equivalent to the list's get method.</li>
* <li> Array -- the {@code index}-th array entry is returned,
* if there is such an entry; otherwise an {@code IndexOutOfBoundsException}
* is thrown.</li>
* <li> Collection -- the value returned is the {@code index}-th object
* returned by the collection's default iterator, if there is such an
element.</li>
* <li> Iterator or Enumeration -- the value returned is the
* {@code index}-th object in the Iterator/Enumeration, if there
* is such an element. The Iterator/Enumeration is advanced to
* {@code index} (or to the end, if {@code index} exceeds the
* number of entries) as a side effect of this method.</li>
* </ul>
*
* @param object the object to get a value from
* @param index the index to get
* @return the object at the specified index
* @throws IndexOutOfBoundsException if the index is invalid
* @throws IllegalArgumentException if the object type is invalid
*/
public static Object get(final Object object, final int index) {
final int i = index;
if (i < 0) {
throw new IndexOutOfBoundsException("Index cannot be negative: " + i);
}
if (object instanceof Map<?,?>) {
final Map<?, ?> map = (Map<?, ?>) object;
final Iterator<?> iterator = map.entrySet().iterator(); {code}
> Create new method in CollectionUtils to return first element if not null
> ------------------------------------------------------------------------
>
> Key: COLLECTIONS-742
> URL: https://issues.apache.org/jira/browse/COLLECTIONS-742
> Project: Commons Collections
> Issue Type: New Feature
> Components: Collection
> Affects Versions: 4.4
> Reporter: Wesllhey Holanda
> Priority: Minor
> Original Estimate: 8h
> Remaining Estimate: 8h
>
> When we try to get the first element into collection, we have to lead with
> null point exception. So with this method, when the collection is null or
> empty, the method will return null, and when not, the method will return the
> first element.
> In this way, the user don't need to write nothing to lead with null point
> exception.
>
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