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use comparator in jdk1.4

 
FY Hsieh
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I have class like



It compiles but gives run time ClassCastException error "Student can not be casted to Comparable". I am not using Comparable. I am using Comparator.
Why do I get that error ? what's the best and easy way to fix assuming I still use Comparator and Arraylist ?
 
Christophe Verré
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If you want to make Students comparable, you should implement the Comparable interface instead. If you insist on making the Student class to be a Comparator as well, you have to use the sort method the following way :

This will tell the Collections class to use a new comparator to compare the Students. That looks awkward though. You should use Comparable instead.
 
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