小程序errcode:40163errmsg:codebeenused

如何看待微信公开课小程序热门讨论「小程序errcode:40163errmsg:codebeenused」
摘要：小程序errcode:40163errmsg:codebeenused
展开：如题，以下是代码publicclassOAuthServletextendsHttpServlet{privatestaticfinallongserialVersionUID1847238807216447030L;publicvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{request.setCharacterEncoding(request.setCharacterEncoding(utf8);response.setCharacterEncoding(utf8);//用户同意授权后，能获取到codeStringcoderequest.getParameter(code);Stringstaterequest.getParameter(state);//用户同意授权if(!authdeny.equals(code)){//获取网页授权access_tokenWeixinOauth2TokenweixinOauth2TokenAdvancedUtil.getOauth2AccessToken(wxe34a90ac7bxxcab85c,1207d566090a8344xxxd6224c02c,code);//网页授权接口访问凭证StringaccessTokenweixinOauth2Token.getAccessToken();//用户标识StringopenIdweixinOauth2Token.getOpenId();//获取用户信息SNSUserInfosnsUserInfoAdvancedUtil.getSNSUserInfo(accessToken,openId);//设置要传递的参数request.setAttribute(snsUserInfo,snsUserInfo);request.setAttribute(state,state);}//跳转到index.jsprequest.getRequestDispatcher(index.jsp).forward(request,response);}}第一次可以获取到信息，但是第二次就code已被使用怎么改才能让code不被重复使用，求具体代码