Re: tomahawk tree2 for clay built up tree structure

[stephan opitz]

thx

2006/7/13, Gary VanMatre <[EMAIL PROTECTED]>:

>From: "stephan opitz" <[EMAIL PROTECTED]>
>
> problem is the structure.
>
> if i have an object containing an id and a parentId (which is null, or
> linking to another object -> the parent one)
>
> if i get a list from db how is it possible to build up the structure
> for the tree2
>
> i tried hashmap or recursive algorithm, but nothing with much success...
>
> any ideas
>

You might consider the following code snippet.


public class TreeBacker {

   public TreeNode findNode(TreeNode root, Integer sarg) {
       Integer id = root.getDescription() == null ? null : new 
Integer(root.getDescription());
       if (compare(id, sarg) == 0) {
           return root;
       }
       Iterator ci = root.getChildren().iterator();
       while (ci.hasNext()) {
           TreeNode found = findNode((TreeNode) ci.next(), sarg);
           if (found != null)
               return found;
       }

       return null;
   }


   public TreeNode getTreeData() {

       TreeNode root = new TreeNodeBase("root", null, false);
       TreeNode current = root; // current root

       Collection dbRows = getDBRows();
       Iterator di = dbRows.iterator();
       while (di.hasNext()) {
           MyVO vo = (MyVO) di.next();

           Integer id = current.getDescription() == null ? null : new 
Integer(current.getDescription());
           int order = compare(id, vo.getParent());

           if (order != 0) {
               current = findNode(root, vo.getParent());
               // if current is null you have an orphaned node
           }

           String type = vo.getParent() == null ? null : 
vo.getParent().toString();
           String desc = vo.getId() == null ? null : vo.getId().toString();

           current.getChildren().add(new TreeNodeBase(type, desc, false));
       }

       return root;
   }




   public Collection getDBRows() {

       // select parent, id from table order by parent, id

       // null, 1
       // null, 2
       // null, 3
       // 1, 4
       // 1, 5
       // 2, 6
       // 2, 7
       // 3, 8
       // 3, 9
       // 9, 10
       // 9, 11

       Set sortedList = new TreeSet();
       sortedList.add(new MyVO(null, new Integer(1)));
       sortedList.add(new MyVO(new Integer(1), new Integer(4)));
       sortedList.add(new MyVO(new Integer(1), new Integer(5)));

       sortedList.add(new MyVO(null, new Integer(2)));
       sortedList.add(new MyVO(new Integer(2), new Integer(6)));
       sortedList.add(new MyVO(new Integer(2), new Integer(7)));

       sortedList.add(new MyVO(null, new Integer(3)));
       sortedList.add(new MyVO(new Integer(3), new Integer(8)));
       sortedList.add(new MyVO(new Integer(3), new Integer(9)));

       sortedList.add(new MyVO(new Integer(9), new Integer(10)));
       sortedList.add(new MyVO(new Integer(9), new Integer(11)));


       return sortedList;
   }

   class MyVO implements Comparable {


       private Integer parent = null;
       private Integer id = null;

       public MyVO(Integer parent, Integer id) {
           this.parent = parent;
           this.id = id;
       }
       public Integer getId() {
           return id;
       }
       public void setId(Integer id) {
           this.id = id;
       }
       public Integer getParent() {
           return parent;
       }
       public void setParent(Integer parent) {
           this.parent = parent;
       }


       public int compareTo(Object obj) {

           MyVO vo = (MyVO) obj;
           int order = compare(parent, vo.parent);
           if (order == 0)
               order = compare(id, vo.id);

           return order;
       }

   }


   public static int compare(Integer col1, Integer col2) {

       if ((col1 == null) && (col2 == null))
           return 0;
       else if ((col1 == null) && (col2 != null))
           return -1;
       else if ((col2 == null) && (col1 != null))
           return 1;
       else
           return ((Comparable) col1).compareTo(col2);
   }



   public static void main(String[] args) {
       TreeBacker backer = new TreeBacker();
       TreeNode root = backer.getTreeData();

   }


}


> stephan

Gary