RESTFB：如何使用java程序在朋友墙上发布消息

Question

我有我朋友的facebook用户名。我想使用restFB API发布他们的墙。我可以张贴在我的墙上。但我如何通过用户名获取user_id。

String user_id =“1234567567”

FacebookType publishMessageResponse = facebookClient.publish("{user_id}/feed", FacebookType.class, Parameter.with("message", "RestFB 1234 "));

这里应该是user_id(always numeric)。或者我们也可以传递用户名。

错误

Received Facebook error response of type OAuthException: Error validating access token: The session is invalid because the user logged out. (code 190, subcode 467) 
com.restfb.exception.FacebookOAuthException: Received Facebook error response of type OAuthException: Error validating access token: The session is invalid because the user logged out. (code 190, subcode 467)