Question

我在将自己的数据库服务器与Google Web应用程序一起使用时遇到了问题。

使用eclips（java EE IDE），安装所有google插件init，并开发一个示例google web应用程序，将其部署到web.Its正常工作。

现在我想在我的应用程序中使用自己的数据库。（在localhost中安装MYSQL）。这里使用Hibernate连接数据库。所有必需的jar文件都放在WEB目录下的lib目录中。

当我运行我的应用程序时，会出现类似错误的错误。

com.google.apphosting.utils.jetty.JettyLogger warn
WARNING: Error for /Home
java.lang.ExceptionInInitializerError
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:169)
    at org.hibernate.connection.DriverManagerConnectionProvider.configure(DriverManagerConnectionProvider.java:57)
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:124)
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:56)
    at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:397)
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:62)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2006)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1289)
    at base.Trackerlogin.service(Trackerlogin.java:56)
    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$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    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 com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doDirectRequest(DevAppServerServersFilter.java:369)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doDirectServerRequest(DevAppServerServersFilter.java:352)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doFilter(DevAppServerServersFilter.java:115)
    at org.mortbay.jetty.servlet.ServletHandler$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.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:421)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)
    at java.security.AccessControlContext.checkPermission(AccessControlContext.java:323)
    at java.security.AccessController.checkPermission(AccessController.java:546)
    at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkPermission(DevAppServerFactory.java:289)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkAccess(DevAppServerFactory.java:314)
    at java.lang.ThreadGroup.checkAccess(ThreadGroup.java:288)
    at java.lang.Thread.init(Thread.java:332)
    at java.lang.Thread.<init>(Thread.java:419)
    at com.mysql.jdbc.AbandonedConnectionCleanupThread.<init>(AbandonedConnectionCleanupThread.java:33)
    at com.mysql.jdbc.NonRegisteringDriver.<clinit>(NonRegisteringDriver.java:88)
    ... 46 more
Apr 26, 2013 10:37:22 AM com.google.apphosting.utils.jetty.JettyLogger warn
WARNING: Nested in java.lang.ExceptionInInitializerError:
java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)
    at java.security.AccessControlContext.checkPermission(AccessControlContext.java:323)
    at java.security.AccessController.checkPermission(AccessController.java:546)
    at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkPermission(DevAppServerFactory.java:289)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkAccess(DevAppServerFactory.java:314)
    at java.lang.ThreadGroup.checkAccess(ThreadGroup.java:288)
    at java.lang.Thread.init(Thread.java:332)
    at java.lang.Thread.<init>(Thread.java:419)
    at com.mysql.jdbc.AbandonedConnectionCleanupThread.<init>(AbandonedConnectionCleanupThread.java:33)
    at com.mysql.jdbc.NonRegisteringDriver.<clinit>(NonRegisteringDriver.java:88)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:169)
    at org.hibernate.connection.DriverManagerConnectionProvider.configure(DriverManagerConnectionProvider.java:57)
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:124)
    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:56)
    at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:397)
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:62)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2006)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1289)
    at base.Trackerlogin.service(Trackerlogin.java:56)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doDirectRequest(DevAppServerServersFilter.java:369)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doDirectServerRequest(DevAppServerServersFilter.java:352)
    at com.google.appengine.tools.development.DevAppServerServersFilter.doFilter(DevAppServerServersFilter.java:115)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:421)
    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$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Apr 26, 2013 10:37:22 AM org.hibernate.connection.DriverManagerConnectionProvider close
INFO: cleaning up connection pool: null

请给出任何想法来实现这个......

Answer 1

你使用Hibernate 4.3.1 Final？

Hibernate的DriverManagerConnectionProvider尝试创建新的线程，这在GAE上是不允许的。我也有这个问题。

在GitHub上查看Google的example告诉我，使用Hibernate 4.2.0.Final可以正常工作。我尝试使用Hibernate 4.3.1运行相同的示例并获得相同的异常。但是4.2使用它就像预期的那样运行。

我要在我的应用程序中降级Hibernate，看看..

Answer 2

本周我尝试在 Google App Engine / Google Cloud Sql项目中使用 Hibernate 4.3.6.Final ，并遇到上述问题（ java.security.AccessControlException ）。在早期的GAE / GCS项目中，我使用了Hibernate 4.3.0.Beta3而没有任何问题。

正如GaëlOberson已在上面所述，问题是Hibernate中默认连接池 DriverManagerConnectionProviderImpl 的新实现。此连接池尝试使用 Executors.newSingleThreadScheduledExecutor 生成新线程;

executorService = Executors.newSingleThreadScheduledExecutor(); executorService.scheduleWithFixedDelay( new Runnable() {...}

This is not allowed on Google App Engine;


Java应用程序可以创建一个新线程，但也有一些   限制如何做到这一点。这些线程不能“活跃”了   请求创建它们。

实际问题是Hibernate配置，它不允许使用无连接池。根据谷歌this connection pool is even not necessary on GAE/GCS;


如何最好地管理数据库连接取决于您的使用案例。   例如，如果创建新数据库连接的时间是   比检查和重用现有连接更重要，那么我们   建议您使用连接池。相反，如果时间到了   创建新连接与测试是否存在大致相同   连接是活着的并重用它，那么我们建议您创建   为每个HTTP请求提供服务的新连接，并将其重用于   请求的持续时间。特别是，后一种情况可能适用于   您从Google App Engine连接到Google Cloud SQL。

<强>概括;我们不需要GAE / GCS上的连接池，但是Hibernate不提供开箱即用的非连接池选项。

由于时间紧迫，我寻求快速解决方案;我编写了自己的DriverManagerConnectionProviderImpl版本。此版本不保留连接管理，只是打开和关闭呼叫连接。还有一些改进的余地，因为我应该在请求期间重复使用连接......另一个解决方案是使用已批准的GAE线程......

在我看来，Hibernate应该为GAE / GCS开发人员提供no pooling选项。 I already posted this topic at the Hibernate Community。

Answer 3

按照：

Appengine拥有自己的MySQL版本Cloud SQL。请参阅有关如何use your own MySQL instance during development的文档。请注意，您无法在生产中使用自己的MySQL。
请参阅有关make Cloud SQL work with Hibernate。

Answer 4

我在尝试使用Class.forName("com.mysql.jdbc.Driver");时遇到了同样的异常，并通过执行以下操作解决了这个问题：

使用com.google.appengine.api.rdbms.AppEngineDriver代替com.mysql.jdbc.Driver
将jdk版本从jdk1.7.0_25更改为jdk1.7.0_21

java.security.AccessControlException：拒绝访问（java.lang.RuntimePermission modifyThreadGroup）

4 个答案: