Google App Engine привет мир программа не работает

Question

Я установил затмение GAE плагин, а затем this простой учебник, и когда я запускаю свою программу, я получаю сообщение об ошибке

Initializing App Engine server 
אוג 23, 2013 12:54:04 PM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml 
INFO: Successfully processed C:\Users\Owner\workspace\GoogleTest2\war\WEB-INF/appengine-web.xml 
אוג 23, 2013 12:54:04 PM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml 
SEVERE: Received exception processing C:\Users\Owner\workspace\GoogleTest2\war\WEB-INF/appengine-web.xml 
com.google.apphosting.utils.config.AppEngineConfigException: appengine-web.xml does not contain a <threadsafe> element. 
See http://code.google.com/appengine/docs/java/config/appconfig.html#Using_Concurrent_Requests for more information. 
You probably want to enable concurrent requests. 
     at com.google.apphosting.utils.config.AppEngineWebXmlReader.readAppEngineWebXml(AppEngineWebXmlReader.java:85) 
     at com.google.apphosting.utils.config.EarHelper.readWebModule(EarHelper.java:166) 
     at com.google.appengine.tools.development.ApplicationConfigurationManager$WarModuleConfigurationHandle.readConfiguration(ApplicationConfigurationManager.java:399) 
     at com.google.appengine.tools.development.ApplicationConfigurationManager.<init>(ApplicationConfigurationManager.java:146) 
     at com.google.appengine.tools.development.ApplicationConfigurationManager.newWarConfigurationManager(ApplicationConfigurationManager.java:88) 
     at com.google.appengine.tools.development.DevAppServerImpl.<init>(DevAppServerImpl.java:137) 
     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 com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:233) 
     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:69) 
     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:53) 
     at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:84) 
     at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509) 
     at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1093) 
     at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:836) 
     at com.google.gwt.dev.DevMode.main(DevMode.java:311) 

    [ERROR] Unable to start App Engine server 
com.google.apphosting.utils.config.AppEngineConfigException: Invalid configuration 
     at com.google.appengine.tools.development.DevAppServerImpl.reportDeferredConfigurationException(DevAppServerImpl.java:414) 
     at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:211) 
     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:1093) 
     at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:836) 
     at com.google.gwt.dev.DevMode.main(DevMode.java:311) 
Caused by: com.google.apphosting.utils.config.AppEngineConfigException: Invalid appengine-web.xml(C:\Users\Owner\workspace\GoogleTest2\war\WEB-INF/appengine-web.xml) - appengine-web.xml does not contain a <threadsafe> element. 
See http://code.google.com/appengine/docs/java/config/appconfig.html#Using_Concurrent_Requests for more information. 
You probably want to enable concurrent requests. 
     at com.google.apphosting.utils.config.EarHelper.readWebModule(EarHelper.java:168) 
     at com.google.appengine.tools.development.ApplicationConfigurationManager$WarModuleConfigurationHandle.readConfiguration(ApplicationConfigurationManager.java:399) 
     at com.google.appengine.tools.development.ApplicationConfigurationManager.<init>(ApplicationConfigurationManager.java:146) 
     at com.google.appengine.tools.development.ApplicationConfigurationManager.newWarConfigurationManager(ApplicationConfigurationManager.java:88) 
     at com.google.appengine.tools.development.DevAppServerImpl.<init>(DevAppServerImpl.java:137) 
     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 com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:233) 
     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:69) 
     at com.google.appengine.tools.development.DevAppServerFactory.createDevAppServer(DevAppServerFactory.java:53) 
     at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:84) 
     ... 4 more 
Unable to start embedded HTTP server 
com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries) 
     at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:102) 
     at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509) 
     at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1093) 
     at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:836) 
     at com.google.gwt.dev.DevMode.main(DevMode.java:311) 
[ERROR] shell failed in doStartupServer method 

Любые идеи, почему? Спасибо!

Answer 1

В вашем файле appengine-web.xml отсутствует запись. Для hello-world вы не хотите иметь дело с параллелизмом (пока), поэтому добавьте:

<threadsafe>false</threadsafe> 

этот файл. Вы найдете его в war/META-INF/.

Как только вы создаете параллельное приложение (приходит намного позже), вы можете установить его в true.