tree的使用

jsp

<div style=" 400px; border: 1px red solid; margin: 10px auto;">
		<ul id="tt" class="easyui-tree"
			data-options="url:'TreeDataServlet',
			idField:'id',textField:'mname',parentField:'parentid'">  <!-- 这几个属性在plug .js里面 --!>
		</ul>
		    <!-- 用到的是plug.js 的插件,需要引到js的包下面,但是,最外面那一层不用再写function(){} --!>    

	</div>

  MenuDao

public class MenuDao extends BaseDao {  //继承
	public List<Map<String, Object>> selectMenu() {   
		String sql="select * from menu";
		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
		initQuery(sql);               
		try {
			while(rs.next()) {
				Map<String, Object> map = new HashMap<String, Object>();   
				map.put("id", rs.getObject("id"));   /*menu表里面的列字段名*/  
				map.put("mname", rs.getObject("mname"));   
				map.put("parentid", rs.getObject("parentid"));     
				list.add(map);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;
	}
}

Servlet

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		MenuDao md = new MenuDao();
		List<Map<String, Object>> list = md.selectMenu();
		response.getWriter().append(JSON.toJSONString(list));
	}