从swing应用程序到servlet进行http调用，会话未保存 [英] Making http calls from swing application to a servlet, session not saved
问题描述
我正在创建一个连接到Web服务器的Swing应用程序，运行一些servlet（由我自己创建）。在用户第一次连接时，他得到一个playerID，保存在servlet上的会话中。当我尝试从Swing应用程序再次调用servlet时，似乎无法识别PlyaerID。我正在进行简单的调用以获取PlayerID。 servlet识别这种类型的请求并发送带有playerID的JSON，如果它没有设置（null），则发送为-1。 swing应用程序总是从servlet获得-1回复。我尝试从浏览器运行它，一切都很好。
I'm creating a Swing application that connects to a web server, running some servlets (created by myself). On the 1st time a user connects, he get a "playerID" that is saved on his session on the servlets. When I try to make another call from the Swing application to the servlet, the "PlyaerID" seems not to be recognized. I'm making a simple call to get the PlayerID. The servlets recognize this type of request and send a JSON with the "playerID" and if it is not set (null) than it sends -1. The swing application always getting the "-1" reply from the servlet. I tried running it from a browser and everything was just fine.
我的Swing客户端是否有可能无法发出请求，并且会话不会保存在servlet上？
Is it possible that my Swing client can not make a request and a session will not be saved on the servlet?
我可以肯定地告诉你，与servlet通信的swing方法效果很好。
I can tell you for sure that the swing method that communicate with the servlet works well.
推荐答案
servlet会话由cookie支持。您基本上需要从第一个请求的响应中获取所有 Set-Cookie 标头，然后传递 name = value 成对后续请求的 Cookie 标头。
The servlet session is backed by a cookie. You basically need to grab all Set-Cookie headers from the response of the first request and then pass the name=value pairs back as Cookie header of the subsequent requests.
目前还不清楚您使用的是哪个HTTP客户端，但是如果它的 java.net.URLConnection ，然后你可以使用 java.net.CookieHandler 。
It's unclear what HTTP client you're using, but if it's java.net.URLConnection, then you could use the java.net.CookieHandler for this.
// First set the default cookie manager.
CookieHandler.setDefault(new CookieManager(null, CookiePolicy.ACCEPT_ALL));
// All the following subsequent URLConnections will use the same cookie manager.
URLConnection connection = new URL(url).openConnection();
// ...
connection = new URL(url).openConnection();
// ...
connection = new URL(url).openConnection();
// ...
参见：
- 使用java.net.URLConnection来触发和处理HTTP请求 - 维护会话
- servlet如何工作？实例化，会话，共享变量和多线程
- Using java.net.URLConnection to fire and handle HTTP requests - Maintaining the session
- How do servlets work? Instantiation, sessions, shared variables and multithreading
See also:
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