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Java getUserObject() return string instead of userobject

After I created a node I'd like to get a MyNodeUserObject so I can call the getFlops() method later. But I can't cast the userobject to MyNodeUserObject.

Creating the node:

MyNodeUserObject userObject = new MyNodeUserObject("aaa","AA-10");

DefaultMutableTreeNode node = new DefaultMutableTreeNode(userObject);


public static void visitAllNodes(DefaultMutableTreeNode node, JTree tree) {
    //java.lang.ClassCastException: java.lang.String cannot be cast to MyNodeUserObject
    MyNodeUserObject nodeInfo = (MyNodeUserObject) node.getUserObject();

MyNodeUserObject.class

public final class MyNodeUserObject{
    private static final long serialVersionUID = 1L;

    private final String flops;
    private final String nodeName;

    public MyNodeUserObject(String nodeName, String flops) {
        this.flops = flops;
        this.nodeName = nodeName;
    }

    public String getFlops() {
        return flops;
    }

    public String getNodeName() {
        return nodeName;
    }

    @Override
    public String toString() {
        return nodeName;
    }

Content of tree.txt:
Node name;IsFolder(true/false);Parent;Flops
my ranges;true; ;
a;false;my ranges;AA,AKs,AKo
b;false;my ranges;66,55,44,33,22
c;false;my ranges;JJ,TT,99,88

Solution

  • Looking at the code you linked in a comment, the root node of your tree actually does contain a String ("<html><b>Ranges</b></html>") as its userObject.

    Given that, your options are

    • Replace the root node with a node around MyNodeUserObject; this probably necessitates some changes to that class to handle the root node correctly
    • Add a special case in the visitAllNodes method (checking for instanceof MyNodeUserObject, for example)
    • Make sure visitAllNodes is not called with the root node