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Thread: Help with sorting Employee class

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    Default Help with sorting Employee class

    A Employee Class where i want to sort there lists one by there salary and one by there name individually as per the requirement ? How we do it?


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    Default re: Help with sorting Employee class

    Hi,

    I didn't get your question.Please post your code what you tried then explain what is your need.

    Happy to Help

    Thanks,

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    Default re: Help with sorting Employee class

    Welcome! Please read this topic to learn how to post code correctly and other useful info for new members.

    Please give your threads better titles.

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    Default Re: Help with sorting Employee class

    A Employee Class with fields of name , age , address, salary and want to sort the objects lists by there salary and also by there name (Two way sorting on a same custom class) using comparator or comparable? How we do it?

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    Default Re: Help with sorting Employee class

    Quote Originally Posted by sunilshiwankar View Post
    A Employee Class with fields of name , age , address, salary and want to sort the objects lists by there salary and also by there name (Two way sorting on a same custom class) using comparator or comparable? How we do it?
    Comparable must be implemented into the class of the objects to sort, so you can have only 1 ordering with Comparable for a given type, that should be the "natural" ordering of the objects (the order on name of Employee can be seen as the "natural" order).
    Comparator must be implemented in other, distinct, classes, so you can have N orderings with Comparator for a given type.

    Please, see, documentation of Comparable/Comparator, implement these interfaces and for any precise doubts, ask.
    Andrea, www.andbin.net SCJP 5 (91%) SCWCD 5 (94%)

    Useful links for Java beginners My new project Java Examples on Google Code

  6. The Following 2 Users Say Thank You to andbin For This Useful Post:

    Ganeprog (February 5th, 2014), jedmustdie (February 5th, 2014)

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    Default Re: Help with sorting Employee class

    can u give me the example of implementing comparator with two ordering ?

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    Default Re: Help with sorting Employee class

    Quote Originally Posted by sunilshiwankar View Post
    can u give me the example of implementing comparator with two ordering ?
    In a very sketchy way:

    public class Book implements Comparable<Book> {
        private String title;
        private String publisher;
     
        // ... constructor(s), getter/setter methods, toString(), etc. ...
     
        public int compareTo(Book other) {
            return getTitle().compareTo(other.getTitle());
        }
    }
     
     
    public class BookPublisherComparator implements Comparator<Book> {
        public int compare(Book book1, Book book2) {
            return book1.getPublisher().compareTo(book2.getPublisher());
        }
    }

    If you a have a primitive field, obviously, you can't use compareTo (title/publisher are String, that is Comparable and has compareTo). For primitives, just use < , > , etc... (or wrap into Integer, etc... or use e.g. compare(int x, int y) of Integer available since Java 7).
    Andrea, www.andbin.net SCJP 5 (91%) SCWCD 5 (94%)

    Useful links for Java beginners My new project Java Examples on Google Code

  9. The Following User Says Thank You to andbin For This Useful Post:

    sunilshiwankar (February 5th, 2014)

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