Sort a list of object w.r.t to a particular member/state

I have a list of java object that have 4 members.

int id;
String 开发者_JAVA百科name;
String age;
int order;

I want to sort the list of this object w.r.t order.

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class Foo {

    private int id;
    private String name;
    private String age;
    private int order;
    //accessors
}

Use Custom Comparator

    List<Foo> list = null;
    Collections.sort(list, new Comparator<Foo>() {

          public int compare(Foo o1, Foo o2) {
            return Integer.valueOf(o1.getOrder()).compareTo(Integer.valueOf( o2.getOrder()));
        }
    });

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1. You can Implement java.lang.Comparable interface and put the sorting logic in compareTo(T o) or else
2. you can have custom java.lang.Comparator and have the logic in compare() method.

I would suggest to implement custom Comparator, as later if you try to modify your sorting criteria, ll be easily done.

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Make the object implement Comparable.

public class Person implements Comparable<Person> {
    private int id;
    private String name;
    private int order;

    public int compareTo(Person p) {
        return p.order - this.order;
    }
}

You can then use objects of this class Person in any sorted list such as PriorityQueue or you could simply use Collections.sort(personList) for that.

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Use a PriorityQueue and let your objects extend Comparable.

You also have to implement the compareTo(object o) method.