后台获取json格式数据。
直接上代码。 最后有一张官方ajax获取tree的说明。

     var ajaxTreeSample = function() {

        $("#tree_4").jstree({
            "core" : {
                "themes" : {
                    "responsive": false
                }, 
                // so that create works
                "check_callback" : true,
                'data' : function (obj, callback) {
                    var jsonstr="[]";
                    var jsonarray = eval('('+jsonstr+')');
                    $.ajax({
                        type: "POST",
                        url:"/bms/wechat/wemenu/show.do",
                        dataType:"json",
                        async: false,
                        success:function(result) {
                            var arrays= result.data;
                            for(var i=0 ; i<arrays.length; i++){
                                var arr = {
                                        "id":arrays[i].menuId,
                                        "parent":arrays[i].parentId=="root"?"#":arrays[i].parentId,
                                        "text":arrays[i].menuName
                                }
                                jsonarray.push(arr);
                            }
                        }

                    });
                    callback.call(this, jsonarray);
                }
            },
            "types" : {
                "default" : {
                    "icon" : "fa fa-folder icon-state-warning icon-lg"
                },
                "file" : {
                    "icon" : "fa fa-file icon-state-warning icon-lg"
                }
            },
            "state" : { "key" : "demo3" },
            "plugins" : [ "dnd", "state", "types" ]
        });

    }