Hierarchical Bookmark Generation in PDF using iTex

I have data in ArrayList like below :

static ArrayList<DTONodeDetail> tree;
public static void main(String[] args) {
    // TODO Auto-generated method stub
    tree=new ArrayList<DTONodeDetail>();

     //first argument->NodeId
     //second->NodeName
     // third -> ParentNodeId

    tree.add(getDTO(1,"Root",0));
    tree.add(getDTO(239,"Node-1",1));
    tree.add(getDTO(242,"Node-2",239));
    tree.add(getDTO(243,"Node-3",239));
    tree.add(getDTO(244,"Node-4",242));
    tree.add(getDTO(245,"Node-5",243));
    displayTree(tree.get(0));       

}

public static DTONodeDetail getDTO(int nodeId,String nodeName,int parentID)
{
    DTONodeDetail dto=new DTONodeDetail();
    dto.setNodeId(nodeId);
    dto.setNodeDisplayName(nodeName);
    dto.setParentID(parentID);

    return dto;
}

I am able to display above data in tree structure like below :

Root
-----Node-1
------------Node-2
------------------Node-4
------------Node-3
------------------Node-5

I have try Using Chapter class of itext library but unable to know how can i generate hierarchical bookmark.

My Question is can i create hierarchical bookmark(like above) in pdf using itext java library?

In PDF terminology, bookmarks are referred to as outlines. Please take a look at the CreateOutline example from my book to find out how to create an outline tree as shown in this PDF: outline_tree.pdf

We start with the root of the tree:

PdfOutline root = writer.getRootOutline();

Then we add a branch:

PdfOutline movieBookmark = new PdfOutline(root, 
            new PdfDestination(
                PdfDestination.FITH, writer.getVerticalPosition(true)),
            title, true);

To this branch, we add a leaf:

PdfOutline link = new PdfOutline(movieBookmark,
            new PdfAction(String.format(RESOURCE, movie.getImdb())),
            "link to IMDB");

And so on.

The key is to use PdfOutline and to pass the parent outline as a parameter when constructing a child outline.

Update based on comment:

There's also an example called BookmarkedTimeTable where we create the outline tree in a completely different way:

ArrayList<HashMap<String, Object>> outlines = new ArrayList<HashMap<String, Object>>();
HashMap<String, Object> map = new HashMap<String, Object>();
outlines.add(map);

In this case, map is the root object to which we can add branches and leaves. Once we're finished, we add the outline tree to the PdfStamper like this:

stamper.setOutlines(outlines);

Note that PdfStamper is the class we need when we manipulate an existing PDF (as opposed to PdfWriter which is to be used when we create a PDF from scratch).

Additional update based on yet another comment:

To create a hierarchy, you just need to add kids.

First level:

HashMap<String, Object> calendar = new HashMap<String, Object>();
calendar.put("Title", "Calendar");

Second level:

HashMap<String, Object> day = new HashMap<String, Object>();
day.put("Title", "Monday");
ArrayList<HashMap<String, Object>> days = new ArrayList<HashMap<String, Object>>();
days.add(day);
calendar.put("Kids", days);

Third level:

HashMap<String, Object> hour = new HashMap<String, Object>();
hour.put("Title", "10 AM");
ArrayList<HashMap<String, Object>> hours = new ArrayList<HashMap<String, Object>>();
hours.add(hour);
day.put("Kids", hours);

And so on...