Easyui-combotree下拉框组合树

例一：agentTree函数内的id为当前点击的子节点的值（id），没有点击为null

<input name="parent_id" id="parent_id" class="easyui-combotree" data-options="width:200,height:30,url:'agentTree',required:false,
value:'${params.parent_id==null?-1:params.parent_id}',queryParams:{selected:'${params.parent_id==null?-1:params.parent_id}'}">
----------------------------------------------------------------------------------------------------------
/**
	 * 获取代理商树数据
	 * selected 表示树有默认选中的值，修改时返显数据
	 * id 表示点击节点时，展开该节点下级树
	 * @throws Exception  */	 
	@RequestMapping(value="/agentTree")
	public @ResponseBody List<Map<String, Object>> agentTree(String id, String selected){
		List<Map<String, Object>> agentTree = new ArrayList<>();
		
		agentTree=agentService.agentInfoTree();
		return agentTree;
	}

----------------------------------------------------------------------------------------------------------
public List<Map<String, Object>> agentInfoTree(){
		List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
		Map<String, Object> treeHeadMap = new HashMap<String, Object>();
		treeHeadMap.put("id", "-1");//上传的数据
		treeHeadMap.put("text", "请选择");//展示的数据
		result.add(treeHeadMap);
		
		String sql = "select ai.id,ai.agent_name from agent_info ai ";

		List<Map<String, Object>> list =  dao.find(sql);
		for(Map<String, Object> user : list){
			String id = user.get("id").toString();
			String agent_name = user.get("agent_name").toString();
			Map<String, Object> option = new HashMap<String, Object>();
			option.put("id", id);//上传的数据
			option.put("text", id+"/"+agent_name);//展示的数据
			result.add(option);
		}
		return result;
	}		<