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  1. #1
    makpandian's Avatar
    makpandian is offline Senior Member
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    Default Array List Sorting

    I need to sort my arraylist which has some java bean objects.I tried Collections.sort() to do so.But I could not.
    Is there any way to do so?
    Mak
    (Living @ Virtual World)

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    JosAH's Avatar
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    Quote Originally Posted by makpandian View Post
    I need to sort my arraylist which has some java bean objects.I tried Collections.sort() to do so.But I could not.
    Is there any way to do so?
    Do your beans implement the Comparable<T> interface? (as stated by the API documentation of the Collections.sort( ... ) method).

    kind regards,

    Jos
    The only person who got everything done by Friday was Robinson Crusoe.

  3. #3
    makpandian's Avatar
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    Default

    I did not.Is the reason for that issue?
    Mak
    (Living @ Virtual World)

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    JosAH's Avatar
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    Quote Originally Posted by makpandian View Post
    I did not.Is the reason for that issue?
    You bet; how else is that sorting method supposed to check if a < b or b < a?
    It needs to compare the objects in the collection so these objects need to be comparable.

    kind regards,

    Jos
    The only person who got everything done by Friday was Robinson Crusoe.

  5. #5
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  6. #6
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    Default

    If you don't want the class to have to implement Comparable you create a Comparator<T> object and use this in the Collections.sort(...) overload that takes a Comparable as the second parameter.

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