Make JTree from database

Question

i have a database with two columns parent and child
and it have following data

parent   |   child 
===================
sara     |   danny
sara     |   benny
dia      |   tom
aria     |   jenny
aria     |   sunny

and i want to display it in JTree like this

-parent
  *sara
      +danny
      +benny
  *dia
      +tom
  *aria
      +jenny
      +sunny

from ResultSet i am getting each row.. but how to create DefaultMutableTreeNode only once and add child in single while loop? how to check if node is already made?

Answer 1

I found this solution, it could be a wrong approach, But it worked. So i called newRow function for each row.

TreeMap group = new TreeMap();

void newRow(String Parent,String Child) {

if(group.containsKey(Parent)) {

    //if Parent already in group return Arraylist of child
    ArrayList<String> al = (ArrayList<String>) group.get(Parent);

    //Add new Child to ArrayList
    al.add(Child);
}
else {
    ArrayList<String> al = new ArrayList<>();
    al.add(Child);

    //if new Parent add parent and its Child ArrayList
    group.put(groupname,al);
}

}

When i iterated through TreeMap group this was the outPut and i used it to make JTree

sara : [danny , benny]
dia : [tom]
aria : [jenny, sunny]