How to group array of objects ?

I have a big array of Student objects.  

Student object has a field coNo;

Now, I plan to group these Students into smaller arrays.  i.e Students who has same coNo should be in same group.

Finally I'd like to print these smaller arrays.

Issue  is , I'll have dynamic no of smaller arrays which I need to prepare from the bigger array. What is the way ?

using JDK 1.5
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You could use Map<String, List<Student>>, where the key is coNo. You can turn that List into Student[] if you really need to.

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zzynxSr. Software engineerCommented:
I'll have dynamic no of ...
Then a List is the most natural way to go (as CEHJ said)

The code looks something like:
Map<String, List<Student>> myMap = new HashMap();
for each student in your big array {
    if (!myMap.contains(student.getCoNo()) {
          List<Student> list = new ArrayList();
          myMap.put(student.getCoNo(), list);
    } else {

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cofactorAuthor Commented:
zzynxSr. Software engineerCommented:
Thanx 4 axxepting
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