jsp中树形结构菜单

<%@ page import="java.util.List" %>
<%@ page import="com.example.MenuItem" %>

<%!
    // 递归方法生成树形菜单
    private void printTree(List<MenuItem> items, int level) {
        for (MenuItem item : items) {
            out.println("<li>" + repeat("&nbsp;&nbsp;&nbsp;&nbsp;", level) + item.getName());
            if (!item.getChildren().isEmpty()) {
                out.println("<ul>");
                printTree(item.getChildren(), level + 1);
                out.println("</ul>");
            }
            out.println("</li>");
        }
    }

    // 辅助方法，用于生成缩进
    private String repeat(String str, int times) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < times; i++) {
            sb.append(str);
        }
        return sb.toString();
    }
%>

<ul>
    <% 
        List<MenuItem> menuItems = (List<MenuItem>) request.getAttribute("menuItems");
        if (menuItems != null) {
            printTree(menuItems, 0);
        }
    %>
</ul>