List to TreeSet conversion produces: "java.lang.ClassCastException: MyClass cannot be cast to java.l

Posted by Chuck on Stack Overflow See other posts from Stack Overflow or by Chuck
Published on 2010-03-24T01:32:46Z Indexed on 2010/03/24 1:43 UTC
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classcastexception

List<MyClass> myclassList = (List<MyClass>) rs.get();

TreeSet<MyClass> myclassSet = new TreeSet<MyClass>(myclassList);

I don't understand why this code generates this:

java.lang.ClassCastException: MyClass cannot be cast to java.lang.Comparable

MyClass does not implement Comparable. I just want to use a Set to filter the unique elements of the List since my List contains unncessary duplicates.

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