Question

我有一個使用gwt的應用程序並託管在gae上。有一種使用xfbml的表單，一旦數據填充並提交表單，就會有一個重定向URL。問題是它通過xfbml表單提交發生異常。如果我直接調用網址，它的效果很好。

的XFBML代碼：

<fb:registration redirect-uri="http://www.sakshum.org/FbBloodDonorRegister" fields='[{"name":"name"},{"name":"first_name"},{"name":"last_name"}, {"name":"cellPhone", "description":"Cell Number", "type":"text"}, {"name":"homePhone", "description":"Home Number", "type":"text"}]' onvalidate="validated" width="530"> 
</fb:registration> 

唯一的例外是下面

javax.servlet.ServletContext log: Exception while dispatching incoming RPC call 
javax.servlet.ServletException: Content-Type was 'application/x-www-form-urlencoded'. Expected 'text/x-gwt-rpc'. 
    at com.google.gwt.user.server.rpc.RPCServletUtils.checkContentTypeIgnoreCase(RPCServletUtils.java:427) 
    at com.google.gwt.user.server.rpc.RPCServletUtils.readContent(RPCServletUtils.java:160) 
    at com.google.gwt.user.server.rpc.RPCServletUtils.readContentAsGwtRpc(RPCServletUtils.java:205) 
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.readContent(AbstractRemoteServiceServlet.java:182) 
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:239) 
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) 
    at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:102) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) 
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) 
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) 
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) 
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) 
    at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:249) 
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) 
    at org.mortbay.jetty.Server.handle(Server.java:326) 
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) 
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923) 
    at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76) 
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) 
    at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135) 
    at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:447) 
    at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:452) 
    at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:458) 
    at com.google.tracing.TraceContext.runInContext(TraceContext.java:698) 
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:336) 
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:328) 
    at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:456) 
    at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251) 
    at java.lang.Thread.run(Thread.java:679) 

Answer 1

看看這個文件，這是上面叫： http://code.google.com/p/google-web-toolkit/source/browse/trunk/user/src/com/google/gwt/user/server/rpc/RPCServletUtils.java

因爲這是在

public static String readContentAsGwtRpc(HttpServletRequest request) 
    throws IOException, ServletException { 
    return readContent(request, GWT_RPC_CONTENT_TYPE, CHARSET_UTF8_NAME); 
} 

鍵指定你不會要能夠很容易地改變預期的內容類型，似乎是你從Facebook的XFBML調用一個RPC特定的servlet。嘗試調用RPC特定的調用是不值得的，你可能無法改變FB如何調用它。最簡單的解決方案是添加另一個接受普通POSTS和GETS的servlet，並從Facebook調用它。

Answer 2

我看到你的錯誤顯示：內容類型是 '應用/的X WWW的形式，進行了urlencoded'。預期'text/x-gwt-rpc'

我會將您的servlet中的預期內容類型更改爲'text/x-gwt-rpc'。你的servlet獲得回調嗎？