It is possible to sort a collection of objects with comparable interface and when you find some attribute equal increment value?
I need to keep a collection ordered by a numeric attribute, identify attributes and increase equal value without losing the ordering
Based on the limited description in the question, you can try with the following code:
class Student implements Comparable < Student >
{
int rollno;
String name;
int age;
Student (int rollno, String name, int age)
{
this.rollno = rollno;
this.name = name;
this.age = age;
}
public int compareTo (Student st)
{
if (age == st.age)
{
st.age += 1;
return -1;
}
else if (age > st.age)
return 1;
else
return -1;
}
}
When you run this code with the following, you get the desired output :
Executing Code:
public static void main (String[]args)
{
ArrayList < Student > al = new ArrayList < Student > ();
al.add (new Student (101, "Vijay", 23));
al.add (new Student (106, "Ajay", 23));
al.add (new Student (105, "Jai", 21));
Collections.sort (al);
for (Student st:al)
{
System.out.println (st.rollno + " " + st.name + " " + st.age);
}
}
Output:
105 Jai 21
106 Ajay 23
101 Vijay 24
