Display xml file in JTree: Select information to be shown in node label

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  • Piet

    Display xml file in JTree: Select information to be shown in node label

    Hi there,
    I have managed to write a small java program that display an xml file
    in a JTree. This was achieved by defining a suitable tree model. THe
    program works...somehow . The nodes (elements and texts) are correctly
    recognized, and the corresponding branches in the JTree can be opened
    and closed. However, when I run the program, all the non-leaf nodes
    (e. g. the element nodes) are displayed from the start tag to the end
    tag including the tag delimiters. Is there any way to control what is
    used as a "node label" in a JTree? Of course that could be done by
    brute (e.g. by building the JTree from simple strings) but I believe
    that this approach will destroy the tree structure of the underlying
    xml file.
    I have tried for some time to display xml data in a tree view, and a
    java solution seemed to be the most "organic" one. So it would be
    great if that program to be really made to work properly. Many thanks
    for any idea how to achieve this! Piet
    Here is the code:
    import java.awt.*;
    import java.awt.event. *;
    import java.util.List;
    import javax.swing.*;
    import javax.swing.tre e.*;
    import javax.swing.eve nt.*;
    import javax.xml.parse rs.*;
    import org.w3c.dom.*;

    public class XmlTreeDemo extends JFrame {
    XmlTreeDemo(Str ing title){
    super(title);
    try{
    DocumentBuilder Factory IDocumentBuilde rFactory
    = DocumentBuilder Factory.newInst ance();
    DocumentBuilder IDocumentBuilde r
    = IDocumentBuilde rFactory.newDoc umentBuilder();
    Document IDocument = IDocumentBuilde r.parse("c:/test1.xml");
    Node root = IDocument.getDo cumentElement() ;
    XmlTreeModel model = new XmlTreeModel(ro ot);
    JTree IJTree = new JTree();
    IJTree.setModel (model);
    getContentPane( ).add(new JScrollPane(IJT ree),BorderLayo ut.CENTER);
    setDefaultClose Operation(JFram e.EXIT_ON_CLOSE );
    }
    catch (Exception e){
    System.err.prin tln(e);
    }
    }
    public static void main(String[] args){
    XmlTreeDemo IJTreeDemo = new XmlTreeDemo("Xm l tree demo");
    IJTreeDemo.pack ();
    IJTreeDemo.show ();
    }
    }
    class XmlTreeModel implements TreeModel{
    protected Node root;
    public XmlTreeModel(No de root){
    this.root = root;
    }
    public Object getRoot(){
    return (Object)this.ro ot;
    }
    public boolean isLeaf(Object node){
    if ((((Node)node). getNodeType() == 7) || (((Node)node).g etNodeType()
    == 1)) return false;
    return true;
    }
    public int getChildCount(O bject parent){
    return ((Node)parent). getChildNodes() .getLength();
    }
    public Object getChild(Object parent,int index){
    Node child = ((Node)parent). getChildNodes() .item(index);
    return (Object)child;
    }
    public int getIndexOfChild (Object parent, Object child){
    NodeList childs = ((Node)parent). getChildNodes() ;
    if (childs.getLeng th() == 0) return -1;
    for (int i=0; i<childs.getLen gth(); i++){
    if (childs.item(i) == (Node)child) return i;
    }
    return -1;
    }
    public void valueForPathCha nged(TreePath path, Object newValue){
    }
    public void addTreeModelLis tener(TreeModel Listener l){
    }
    public void removeTreeModel Listener(TreeMo delListener l){
    }
    }
  • Raymond DeCampo

    #2
    Re: Display xml file in JTree: Select information to be shown innode label

    Piet wrote:[color=blue]
    > Hi there,
    > I have managed to write a small java program that display an xml file
    > in a JTree. This was achieved by defining a suitable tree model. THe
    > program works...somehow . The nodes (elements and texts) are correctly
    > recognized, and the corresponding branches in the JTree can be opened
    > and closed. However, when I run the program, all the non-leaf nodes
    > (e. g. the element nodes) are displayed from the start tag to the end
    > tag including the tag delimiters. Is there any way to control what is
    > used as a "node label" in a JTree? Of course that could be done by
    > brute (e.g. by building the JTree from simple strings) but I believe
    > that this approach will destroy the tree structure of the underlying
    > xml file.[/color]

    The default rendering will call toString() on the object associated to
    the node. So, if appropriate, you could override toString() to get what
    you want.

    Of course, that is the easy way and is frequently not possible. In such
    a case, you can implement and set a custom TreeCellRendere r to display
    whatever you like.

    Ray

    --
    XML is the programmer's duct tape.

    Comment

    • Piet

      #3
      Re: Display xml file in JTree: Select information to be shown in node label

      Raymond DeCampo <rdecampo@spam. twcny.spam.rr.s pam.com.spam> wrote in message news:<kK3Ac.860 66$j24.20715@tw ister.nyroc.rr. com>...
      Hi Raymond,
      many thanks for the hint! In fact it was only 10 lines of code to improve it.
      Piet

      Comment

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