JSF/ICEfaces Dynamic hierarchy tree example

Question

i have list of departments and each department might have a parent or not,department domain object is as follows:

- departmentId
- parentDepartmentId (null if current department has no parent i,e should be under root directly, and have value if current department have parent).
.
.
.

looking at icefaces tutorial code for creating basic tree:

// create root node with its children expanded
    DefaultMutableTreeNode rootTreeNode = new DefaultMutableTreeNode();
    IceUserObject rootObject = new IceUserObject(rootTreeNode);
    rootObject.setText("Root Node");
    rootObject.setExpanded(true);
    rootTreeNode.setUserObject(rootObject);

    // model is accessed by by the ice:tree component via a getter method, this object is what's needed in the view to display the tree
    model = new DefaultTreeModel(rootTreeNode);

    // add some child nodes
    for (int i = 0; i <3; i++) {
        DefaultMutableTreeNode branchNode = new DefaultMutableTreeNode();
        IceUserObject branchObject = new IceUserObject(branchNode);
        branchObject.setText("node-" + i);
        branchNode.setUserObject(branchObject);
        rootTreeNode.add(branchNode);
    }

it's all about constructing basic node, and adding childs.

my case is complex that child A which is under root may have child nodes B,C,D and D have for example child nodes and so on so on.

so i am thinking of a best practice about how to accomplish something like that, i need a sample code or hints if anyone can help.

Answer 1

finally i was able to do it as follows:

List<Department> departmentList = getAllDepartments();
            // create root node with its children expanded
            DefaultMutableTreeNode rootTreeNode = new DefaultMutableTreeNode();
            IceUserObject rootObject = new IceUserObject(rootTreeNode);
            rootObject.setText("Root");
            rootObject.setExpanded(true); 
            rootTreeNode.setUserObject(rootObject);

            HashMap<Department, DefaultMutableTreeNode> createdNodesMap = new HashMap<Department, DefaultMutableTreeNode>(
                    0);

            for (Department department : departmentList) {

                DefaultMutableTreeNode currentNode = null;

                if (createdNodesMap.get(department) == null) {
                    log.debug("############ CREATING NODE "
                            + department.getName());
                    currentNode = new DefaultMutableTreeNode();
                    IceUserObject currentObject = new IceUserObject(currentNode);
                    currentObject.setText(department.getName());
                    currentObject.setExpanded(true);
                    currentNode.setUserObject(currentObject);

                    if (department.getParentDepartment() == null) {
                        rootTreeNode.add(currentNode);
                        log.debug("######### NODE " + department.getName()
                                + " ADDED UNDER ROOT");
                    }

                    createdNodesMap.put(department, currentNode);
                } else {
                    log.debug("############ GETTING CREATED NODE "
                            + department.getName());
                    currentNode = createdNodesMap.get(department);
                }

                if (department.getChildren().size() > 0)
                    log.debug("############ NODE " + department.getName()
                            + " HAVE " + department.getChildren().size()
                            + " CHILDREN");
                else
                    log.debug("############ NODE " + department.getName()
                            + " DOES NOT HAVE CHILDREN");

                for (Department department2 : department.getChildren()) {

                    log.debug("############ CREATING CHILD "
                            + department2.getName() + " FOR PARENT "
                            + department.getName());
                    DefaultMutableTreeNode branchNode;
                    if (createdNodesMap.get(department2) == null) {
                        branchNode = new DefaultMutableTreeNode();
                        IceUserObject branchObject = new IceUserObject(
                                branchNode);
                        branchObject.setText(department2.getName());
                        branchObject.setExpanded(true);
                        branchNode.setUserObject(branchObject);
                    } else
                        branchNode = createdNodesMap.get(department2);

                    createdNodesMap.put(department2, branchNode);
                    currentNode.add(branchNode);
                }

            }

            model = new DefaultTreeModel(rootTreeNode);