http 503 错误 gwt 码头服务器 SERVICE_UNAVAILABLE

Question

在 Web 浏览器中运行项目时，我从 Eclipse 集成码头服务器收到 503 错误。由于我更改了项目的 gae 应用程序 ID，因此出现此错误。

java.lang.ClassNotFoundException: com.google.api.server.spi.SystemServiceServlet
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:176)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.mortbay.util.Loader.loadClass(Loader.java:91)
at org.mortbay.util.Loader.loadClass(Loader.java:71)
at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:73)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:191)
at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:239)
at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:146)
at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:97)
at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
at com.google.gwt.dev.DevMode.main(DevMode.java:311)
    21.08.2012 16:09:42 com.google.appengine.tools.development.ApiProxyLocalImpl log
    SCHWERWIEGEND: javax.servlet.ServletContext log: unavailable
    javax.servlet.UnavailableException: com.google.api.server.spi.SystemServiceServlet
at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:79)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at   com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerS ervice.java:191)
at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:239)
at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:146)
at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:97)
at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
at com.google.gwt.dev.DevMode.main(DevMode.java:311)

    21.08.2012 16:09:42 com.google.apphosting.utils.jetty.JettyLogger warn
    WARNUNG: failed SystemServiceServlet: java.lang.NullPointerException
    21.08.2012 16:09:43 com.google.apphosting.utils.jetty.JettyLogger warn
    WARNUNG: Failed startup of context    com.google.appengine.tools.development.DevAppEngineWebAppContext@9f4160a{/,C:\Users\dp\work        space\fooApp\war}
    java.lang.NullPointerException
     at java.lang.Class.isAssignableFrom(Native Method)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:256)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:191)
at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:239)
at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:146)
at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:97)
at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
at com.google.gwt.dev.DevMode.main(DevMode.java:311)
    21.08.2012 16:09:46 com.google.appengine.tools.development.DevAppServerImpl start
    INFO: The server is running at http://localhost:8888/
    21.08.2012 16:09:46 com.google.appengine.tools.development.DevAppServerImpl start
    INFO: The admin console is running at http://localhost:8888/_ah/admin

这是我的 web.xml 文件

<!-- Default page to serve -->
<welcome-file-list>
   <welcome-file>fooApp.html</welcome-file>
</welcome-file-list>
<servlet>
   <servlet-name>phonegapfileapi</servlet-name>
   <servlet           class>com.googlecode.gwtphonegap.server.file.FileRemoteServiceServlet</servlet-class>
   </servlet>
   <servlet-mapping>
      <servlet-name>phonegapfileapi</servlet-name>
      <url-pattern>/showcase/phonegapfileapi</url-pattern>
   </servlet-mapping>
   <servlet>
       <servlet-name>SystemServiceServlet</servlet-name>
       <servlet-class>com.google.api.server.spi.SystemServiceServlet</servlet-class>
       <init-param>
          <param-name>services</param-name>
       <param-value/>
     </init-param>
   </servlet>

   <servlet-mapping>
      <servlet-name>SystemServiceServlet</servlet-name>
      <url-pattern>/_ah/spi/*</url-pattern>
   </servlet-mapping>

所有的 jars 都在 fooApp/war/WEB-INF/lib 我该如何解决这个问题？ 请帮忙。

Answer 1

我遇到了同样的问题。 SystemServiceServlet 似乎只有在您想在码头中部署 Web 管理 servlet 时才需要。

在我的情况下，问题是 GAE eclipse 插件默认使用 GAE Java SDK 1.6 并且包 com.google.api.server 甚至不存在。我通过手动将 SDK 设置为 GAE SDK 1.7 来修复它。

更改 SDK 时要小心，我尝试更改默认 SDK，但在我选择指向 1.7 的“使用特定 SDK”之前仍然存在此问题。

Answer 2

我正在使用 maven，但遇到了同样的问题。使用 maven，我们没有在项目属性中设置 SDK 版本，而是有这个插件：

<plugin>
    <groupId>com.google.appengine</groupId>
    <artifactId>appengine-maven-plugin</artifactId>
    <version>1.8.3</version>

解决异常： Window/Show View/Other... > Servers/Server 然后右键单击使用的 AppEngine 服务器然后单击 Clean...。

注意：这将擦除您的本地开发数据存储，因此如果您想保留数据，请备份文件：

.../workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp${SERVER_NUM}/${DEPLOYED_APP_NAME}/WEB-INF/appengine-generated/local_db.bin

Answer 3

在我的情况下的解决方案 - 只需在任务管理器中杀死所有 javaw.exe *32 进程。