PriorityQueue in MATLAB using JAVA

[Udaranga]

Hi,
I created a PriorityQueue by using this command.
>>P = java.util.PriorityQueue;

But there is a problem when adding elements. I can only add the first element.
The command I used was
>>P.add({1,1});

When i try to add more i get the below error
-----------------------------------------------------------------------------
??? Java exception occurred:
java.lang.ClassCastException:
[Ljava.lang.Object; cannot be cast to
java.lang.Comparable
at
java.util.PriorityQueue.siftUpComparable(Unknown Source)

at java.util.PriorityQueue.siftUp(Unknown Source)

at java.util.PriorityQueue.offer(Unknown Source)

at java.util.PriorityQueue.add(Unknown Source)
------------------------------------------------------------------------------

Why is that ? What is the solution ??