java - Sort two arrayLists concurrently -

say have 2 arraylists:

name: [four, three, one, two] num:  [4, 3, 1, 2] 

if do: arrays.sort(num), have:

name: [four, three, one, two] num:  [1, 2, 3, 4] 

is there way can possibly sort on num , have reflected in name well, might end with:

name: [one, two, three, four] num:  [1, 2, 3, 4] 

? please me out. thought of comparators , objects, barely know them @ all.

you should somehow associate name , num fields 1 class , have list of instances of specific class. in class, provide compareto() method checks on numerical values. if sort instances, name fields in order desire well.

class entity implements comparable<entity> {     string name;     int num;     entity(string name, int num) {         this.name = name;         this.num = num;     }     @override     public int compareto(entity o) {         if (this.num > o.num)             return 1;         else if (this.num < o.num)             return -1;         return 0;     } } 

test code this:

public static void main(string[] args) {     list<entity> entities = new arraylist<entity>();     entities.add(new entity("one", 1));     entities.add(new entity("two", 2));     entities.add(new entity("three", 3));     entities.add(new entity("four", 4));     collections.sort(entities);      (entity entity : entities)         system.out.print(entity.num + " => " + entity.name + " "); } 

output:

1 => 1 2 => 2 3 => 3 4 => four