我不熟悉使用Facebook应用程序环境。我正在开发一个小应用程序。我正在尝试在项目中使用一些社交数据来检查某些条件。我不知道我是否以正确的方式访问FB返回的JSON对象，但这是我的问题。
我想将名字从当前文件发送到另一个jsp或servlet。因此，我创建了jsp变量，并尝试在从Facebook获得的响应对象中分配“名称”的值。
[尝试在jsp文件末尾打印名字时，名字输出为空。如何在对象中使用名称和性别值并将其发送到另一个jsp文件或servlet文件？
B着头寻找解决方案。有人请帮忙！
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Facebook authentication usage</title>
</head>
<body>
<%! String firstname="";
String lastname="";
String middlename="lynne";
%>
<div id="fb-root"></div>
<script>
window.fbAsyncInit = function() {
// init the FB JS SDK
FB.init({
appId : '532238706811106', // App ID from the App Dashboard
//channelUrl : '//WWW.YOUR_DOMAIN.COM/channel.html', // Channel File for x-domain communication
status : true, // check the login status upon init?
cookie : true, // set sessions cookies to allow your server to access the session?
frictionlessRequests : true,
xfbml : true // parse XFBML tags on this page?
});
// Additional initialization code such as adding Event Listeners goes here
FB.getLoginStatus(function(response) {
if (response.status === 'connected')
{
// the user is logged in and has authenticated your
// app, and response.authResponse supplies
// the user's ID, a valid access token, a signed
// request, and the time the access token
// and signed request each expire
var uid = response.authResponse.userID;
var accessToken = response.authResponse.accessToken;
FB.api('/me', function(response)
{
console.log(response);
console.log('Good to see you, ' + response.name + '.');
firstname=firstname+response.name;
lastname=lastname+response.last_name;
document.write(response.name+middlename);
});
}
else if (response.status === 'not_authorized')
{
// the user is logged in to Facebook,
// but has not authenticated your app
var oauth_url = 'https://www.facebook.com/dialog/oauth/';
oauth_url += '?client_id=532238706811106'; //Your Client ID
oauth_url += '&redirect_uri=' + 'https://apps.facebook.com/newjsp'; //Send them here if they're not logged in
//oauth_url += '&scope=user_about_me,email,user_location,user_photos,publish_actions,user_birthday,user_likes';
window.top.location = oauth_url;
}
else
{
// the user isn't logged in to Facebook.
window.top.location ='https://www.facebook.com/index.php';
}
});
};
// Load the SDK's source Asynchronously
// Note that the debug version is being actively developed and might
// contain some type checks that are overly strict.
// Please report such bugs using the bugs tool.
(function(d, debug)
{
var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
if (d.getElementById(id)) {return;}
js = d.createElement('script'); js.id = id; js.async = true;
js.src = "//connect.facebook.net/en_US/all" + (debug ? "/debug" : "") + ".js";
ref.parentNode.insertBefore(js, ref);
}(document, /*debug*/ false));
</script>
<h1>this is a sample to test facebook authentication
Welcome <%=firstname+""+lastname+middlename%></h1>
<%out.print(firstname+""+lastname+""+middlename); %>
</body>
</html>
firstname=firstname+response.name;没有设置Java代码中先前定义的String变量。相反，它设置了一个新变量，该变量只能由您的JavaScript代码看到。您的Java代码在服务器端运行，而JavaScript在客户端运行。它们是两个完全不同的程序，在完全不同的位置在不同的时间执行。由于这样的原因，不建议在同一文件中同时编写客户端和服务器端代码。
关于解决问题的方法，我建议要么为Facebook寻找Java API，以便可以在呈现JSP之前使用它，要么以JavaScript代码访问从FB返回的数据。仔细阅读Java，JavaScript，服务器端和客户端代码之间的差异也是个好主意。