1.把传的值保存在encodeURI中，记得是双encodeURI

url:'json/selectUser.action?param='+encodeURI(encodeURI("中文")),

HttpServletRequest request = ServletActionContext.getRequest();
		
		String param = request.getParameter("param");
	    
		param = URLDecoder.decode(param,"UTF-8");

System.out.println(param);