The insertNodeInto method doesn't work for my JTree

[LianaN]

Hi!


Initially, I have a data set stored in the database and a BLANK JTree. This data set contains a tree structure, e.g.:
1. Documents
1.1 Correspondence
1.1.1 Incoming
1.1.2 Outgoing
1.2 Contracts
etc.

What I need, is to build the JTree based on the above-shown information. The problem is that insertNodeInto doesn't work properly in my code - only second-level nodes are added to the root node, while the path to the other nodes is not found. Where is the problem? Thanks!

#
public static void traverse( Object hierarchy[], Object hierarchyChildOf[], int k ) {
for(int i = 0; i < hierarchy.length; i++) {
if (hierarchy[k].equals(hierarchyChildOf[i])) {
  MutableTreeNode childNode = new DefaultMutableTreeNode(hierarchy[i]);
  try {
    TreePath path = tree1.getNextMatch(hierarchyChildOf[i].toString(), 0, Position.Bias.Forward);
     if (path != null) {
        MutableTreeNode parentNode = (DefaultMutableTreeNode)  (MutableTreeNode) path.getLastPathComponent();
        treeModel.insertNodeInto(childNode, parentNode, parentNode.getChildCount());
         System.out.println("The child node " + hierarchy[i] + " is added to the parent node " + hierarchyChildOf[i]);
     } else { 
         System.out.println("The path to the parent node " + hierarchyChildOf[i] + "  cannot be found.");
   }
   } catch (Exception e) {
       e.printStackTrace();
   }
       traverse(hierarchy, hierarchyChildOf, i);
   }
 }
}

      public static void createTree() {
         ...
         tree1 = new JTree(); tree1.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
         root = new DefaultMutableTreeNode(hierarchy[0]);
         treeModel = (DefaultTreeModel)tree1.getModel();
         treeModel.setRoot(root);
         traverse( hierarchy, hierarchyChildOf, 0 );
         ...
      }

This is output of System.out.println

The child node Contracts is added to the parent node Documents
The child node Correspondence is added to the parent node Documents
The path to the parent node Correspondence cannot be found.
The path to the parent node Correspondence cannot be found.
The child node Inner documents is added to the parent node Documents
The child node Labour contracts is added to the parent node Documents

[LianaN]

I'll try to be more specific.

There are two arrays filled from DB:
* hierarchy[]: Documents, Correspondence, Incoming, Outgoing, Contracts
* hierarchyChildOf[]: null, Documents, Correspondence, Correspondence, Documents

For instance, hierarchy[1] (Correspondence) is a child of hierarchyChildOf[2] (Documents). Now I must populate JTree with these data. The task is just to add all nodes defined in hierarchy[] to corresponding parent nodes specified in hierarchyChildOf[].

Below you may find my comments on the code:

      public static void traverse( Object hierarchy[], Object hierarchyChildOf[], int k ) {
      for(int i = 0; i < hierarchy.length; i++) {
      // We are searching children of hierarchy[k].
      // If hierarchy[k] is equal to hierarchyChildOf[i], then it means that
      // hierarchy[i] is a child of hierarchy[k]
      if (hierarchy[k].equals(hierarchyChildOf[i])) {
      MutableTreeNode childNode = new DefaultMutableTreeNode(hierarchy[i]);
      try {
      // We are searching the node hierarchyChildOf[i] in the JTree->tree1
      TreePath path = tree1.getNextMatch(hierarchyChildOf[i].toString(), 0, Position.Bias.Forward);
      if (path != null) {
      // If such node exists, then the childNode hierarchy[i] is added
      // to the parentNode hierarchyChildOf[i]
      MutableTreeNode parentNode = (DefaultMutableTreeNode)(MutableTreeNode) path.getLastPathComponent();
      treeModel.insertNodeInto(childNode, parentNode, parentNode.getChildCount());
      System.out.println("The child node " + hierarchy[i] + " is added to the parent node " + hierarchyChildOf[i]);
      } else {
      System.out.println("The path to the parent node " + hierarchyChildOf[i] + " cannot be found.");
      }
      } catch (Exception e) {
      e.printStackTrace();
      }
      traverse(hierarchy, hierarchyChildOf, i);
      }
      }
      }

Any ideas how to implement it correctly?

[LianaN]

I've solved the problem in the following way:

        Hashtable h = new Hashtable();
        for (int i = 0; i < hierarchy.length; i++) {
           Hashtable child = new Hashtable();
           for(int j = 0; j < hierarchy.length; j++) {
              if (hierarchy[i].equals(hierarchyChildOf[j])) {
                  child.put(hierarchy[j],hierarchy[j]);
              }
           }
           if (!child.isEmpty()) h.put(hierarchy[i], child);
        }

        tree1 = new JTree(h);