我在Java7上运行良好的GAE服务。然而，最新的Java 8堆栈承诺更环保。迁移看起来很简单，只需将appengine-web.xml中的标记java7更改为java8即可。
当我部署它时，事情本质上是有效的。那是我的应用程序实际上正在运行。然而，一些我很难使用的端点，但只是为（后来的）API可用性提供的东西似乎不满意自己配置。
我看到的是频繁的异常导致我的实例每隔几分钟启动一次，这使得该服务成为糟糕的服务。
build.xml中的GAE依赖项是：
appengineSdk 'com.google.appengine:appengine-java-sdk:1.9.56'
compile 'com.google.appengine:appengine-endpoints:1.9.56'
compile 'javax.servlet:servlet-api:2.5'
第一个例外是
com.google.apphosting.runtime.jetty9.JettyLogger warn: /_ah/spi/BackendService.getApiConfigs (JettyLogger.java:29)
java.lang.NullPointerException
at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:100)
at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:71)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:848)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1772)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1759)
at com.google.apphosting.runtime.jetty9.SaveSessionFilter.doFilter(SaveSessionFilter.java:37)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1759)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1759)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:48)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1759)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:582)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1180)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:512)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1112)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at com.google.apphosting.runtime.jetty9.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:297)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
at org.eclipse.jetty.server.Server.handle(Server.java:534)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:320)
at com.google.apphosting.runtime.jetty9.RpcConnection.handle(RpcConnection.java:219)
at com.google.apphosting.runtime.jetty9.RpcConnector.serviceRequest(RpcConnector.java:81)
at com.google.apphosting.runtime.jetty9.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:108)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchServletRequest(JavaRuntime.java:650)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchRequest(JavaRuntime.java:612)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:582)
at com.google.apphosting.runtime.JavaRuntime$NullSandboxRequestRunnable.run(JavaRuntime.java:776)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:263)
at java.lang.Thread.run(Thread.java:745)
当我尝试双重部署（在类似情况下找到某个提示）时，我也会看到以下异常。可能是因为第一个从未完成开始？！
22:57:22.062
com.google.api.server.spi.SystemService invokeServiceMethod: exception occurred while calling backend method (SystemService.java:398)
com.google.api.server.spi.response.BadRequestException: API backend's app revision '404386567826848557' not the same as expected '404386523181597065'
at com.google.api.server.spi.BackendService.getApiConfigs(BackendService.java:92)
at sun.reflect.GeneratedMethodAccessor20.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:42)
at com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:363)
at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:113)
at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:71)
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$CachedChain.doFilter(ServletHandler.java:1166)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:297)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:320)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:312)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458)
at java.lang.Thread.run(Thread.java:745)