简而言之，在将我的（Java）应用程序部署到GAE时，GAE会在其中一个捆绑的jar中为类抛出java.lang.NoClassDefFoundError。在我的测试环境中，一切都运行良好。
例外是：
java.lang.NoClassDefFoundError：org.jcp.xml.dsig.internal.dom.XMLDSigRI是一个受限制的类。有关详细信息，请参阅Google App Engine开发人员指南。
但是运行jar -tf xmlsec-1.4.0.jar显示“jar”中存在“缺失”类。
为什么这门课程会受到“限制”？我怎样才能找出原因？ 我正在运行第三方servlet，需要这个包（和这个类）才能工作。 （http://sourceforge.net/projects/saml2api/） 怎么办？
以下是GAE的完整错误消息：
Uncaught exception from servlet
java.lang.NoClassDefFoundError: org.jcp.xml.dsig.internal.dom.XMLDSigRI is a restricted class. Please see the Google App Engine developer's guide for more details.
at com.google.apphosting.runtime.security.shared.stub.org.jcp.xml.dsig.internal.dom.XMLDSigRI.<clinit>(XMLDSigRI.java)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.eclipse.higgins.saml2idp.saml2.XMLElement.<clinit>(XMLElement.java:95)
at no.ntnu.it.fw.saml2api.SAML2Util.createSAMLAuthnRequest(SAML2Util.java:180)
at no.ntnu.it.fw.saml2api.http.LoginServlet.doExecute(LoginServlet.java:184)
at no.ntnu.it.fw.saml2api.http.LoginServlet.doPost(LoginServlet.java:71)
at no.ntnu.it.fw.saml2api.http.LoginServlet.doGet(LoginServlet.java:65)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:693)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$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:238)
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$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135)
at com.google.apphosting.runtime.JavaRuntime.handleRequest(JavaRuntime.java:250)
at com.google.apphosting.base.RuntimePb$EvaluationRuntime$6.handleBlockingRequest(RuntimePb.java:7115)
at com.google.apphosting.base.RuntimePb$EvaluationRuntime$6.handleBlockingRequest(RuntimePb.java:7113)
at com.google.net.rpc.impl.BlockingApplicationHandler.handleRequest(BlockingApplicationHandler.java:24)
at com.google.net.rpc.impl.RpcUtil.runRpcInApplication(RpcUtil.java:398)
at com.google.net.rpc.impl.Server$2.run(Server.java:852)
at com.google.tracing.LocalTraceSpanRunnable.run(LocalTraceSpanRunnable.java:56)
at com.google.tracing.LocalTraceSpanBuilder.internalContinueSpan(LocalTraceSpanBuilder.java:576)
at com.google.net.rpc.impl.Server.startRpc(Server.java:807)
at com.google.net.rpc.impl.Server.processRequest(Server.java:369)
at com.google.net.rpc.impl.ServerConnection.messageReceived(ServerConnection.java:442)
at com.google.net.rpc.impl.RpcConnection.parseMessages(RpcConnection.java:319)
at com.google.net.rpc.impl.RpcConnection.dataReceived(RpcConnection.java:290)
at com.google.net.async.Connection.handleReadEvent(Connection.java:474)
at com.google.net.async.EventDispatcher.processNetworkEvents(EventDispatcher.java:831)
at com.google.net.async.EventDispatcher.internalLoop(EventDispatcher.java:207)
at com.google.net.async.EventDispatcher.loop(EventDispatcher.java:103)
at com.google.net.rpc.RpcService.runUntilServerShutdown(RpcService.java:251)
at com.google.apphosting.runtime.JavaRuntime$RpcRunnable.run(JavaRuntime.java:417)
at java.lang.Thread.run(Unknown Source)