http://www.jstree.com/documentation/types

http://code.google.com/p/struts2-jquery/source/detail?r=1458

Issue 545 has been merged into this issue.

Example:

    <s:set id="contextPath"  value="#request.get('javax.servlet.forward.context_path')" />
    <sjt:tree 
        id="treeTypes" 
        jstreetheme="default" 
        openAllOnLoad="true" 
        types="{
                'valid_children' : [ 'root' ],
                'types' : {
                    'root' : {
                        'icon' : { 
                            'image' : '%{contextPath}/images/root.png' 
                        },
                        'valid_children' : [ 'folder', 'file' ],
                    },
                    'folder' : {
                        'icon' : { 
                            'image' : '%{contextPath}/images/folder.png' 
                        },
                        'valid_children' : [ 'folder', 'file' ],
                    },
                    'file' : {
                        'icon' : { 
                            'image' : '%{contextPath}/images/file.png' 
                        },
                        'valid_children' : [ 'none' ],
                    }
            }
    }">
        <sjt:treeItem title="Root" type="root">
            <sjt:treeItem title="Folder One"  type="folder">
                <sjt:treeItem title="File One" type="file"/>
                <sjt:treeItem title="File Two" type="file"/>
            </sjt:treeItem>
            <sjt:treeItem title="Folder Two"  type="folder">
                <sjt:treeItem title="Folder Three"  type="folder">
                    <sjt:treeItem title="File Four" type="file"/>
                </sjt:treeItem>
                <sjt:treeItem title="File Three" type="file"/>
            </sjt:treeItem>
        </sjt:treeItem>
    </sjt:tree>

This will work with json data ?

No this is for static trees only. But with JSON based Trees you can control the types in your JSON Action and change the Icon with setIcon.