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From "Ganesh Gowtham (JIRA)" <>
Subject [jira] Created: (COLLECTIONS-329) Sorting the collection based on bean property in "CollectionUtils"
Date Sat, 13 Jun 2009 13:37:07 GMT
Sorting the collection based on bean property in "CollectionUtils"

                 Key: COLLECTIONS-329
             Project: Commons Collections
          Issue Type: New Feature
          Components: Collection, Comparator
    Affects Versions: 3.2
         Environment: JDK 1.5 and above , Apache Collections 
            Reporter: Ganesh Gowtham
            Priority: Minor

Hi Folks , 

Thanks for your good work done in Collection Framework .

It would be good if you add functionality to sort the collection based on bean's property
name . ( CollectionsUtils,java)

For example i have List<Person> , i should be able to sort (ascending or desending )
based on person's salary (or) firstName (or) lastName (or) may be the combination of above

below is the equivalent in SQL 

(select * from person order by salary,firtsName,lastName asc ) 

method looks like 

public static <T> void sort(List<T> list, boolean isAscending,String... beanPropertyName)
		Collection<Comparator<T>> beanComparatorCollection = new ArrayList<Comparator<T>>(beanPropertyName.length);
		for(int i =0;i<beanPropertyName.length;i++)
			beanComparatorCollection.add(new BeanComparator(beanPropertyName[i]));
		Comparator<T> finalComparator = ComparatorUtils.chainedComparator(beanComparatorCollection);
		if (!isAscending) {
			finalComparator = new ReverseComparator(finalComparator);
		Collections.sort(list, finalComparator);

Please let me know if you need any details , infact i able to submit patch too .

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