我配置了GWT 2.4.0 + Hibernate 4.x
我使用数据传输对象（DTO）作为GWT教程之后的集成策略： https://developers.google.com/web-toolkit/articles/using_gwt_with_hibernate
但是，当我将项目作为Web应用程序运行时（使用Google eclipse插件），抛出了这个异常：
引起：java.lang.NoClassDefFoundError：java.net.Socket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。
完整的例外：
Initial SessionFactory creation failed.java.lang.NoClassDefFoundError: java.net.Socket is a restricted class. Please see the Google App Engine developer's guide for more details.
01/04/2012 22:11:39 com.google.appengine.tools.development.ApiProxyLocalImpl log
GRAVE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String web.reg.client.GreetingService.greetServer(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: java.lang.ExceptionInInitializerError
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
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$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:60)
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:122)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$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:78)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:363)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$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$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.ExceptionInInitializerError
at web.reg.util.HibernateUtil.<clinit>(HibernateUtil.java:17)
at web.reg.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:104)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
... 34 more
Caused by: java.lang.NoClassDefFoundError: java.net.Socket is a restricted class. Please see the Google App Engine developer's guide for more details.
at com.google.appengine.tools.development.agent.runtime.Runtime.reject(Runtime.java:51)
at org.hsqldb.HsqlSocketFactory.createSocket(Unknown Source)
at org.hsqldb.HSQLClientConnection.openConnection(Unknown Source)
at org.hsqldb.HSQLClientConnection.initConnection(Unknown Source)
at org.hsqldb.HSQLClientConnection.<init>(Unknown Source)
at org.hsqldb.jdbc.jdbcConnection.<init>(Unknown Source)
at org.hsqldb.jdbcDriver.getConnection(Unknown Source)
at org.hsqldb.jdbcDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:154)
at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:173)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcServicesImpl.java:242)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:117)
at org.hibernate.service.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:75)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:159)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131)
at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:71)
at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2273)
at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2269)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1738)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1778)
at web.reg.util.HibernateUtil.<clinit>(HibernateUtil.java:13)
我在这个论坛上读过：http://www.mail-archive.com/google-web-toolkit@googlegroups.com/msg44312.html 我应该在eclipse上取消选中“使用Google App Engine”选项，同时删除这个谷歌应用引擎引用的jar。
好的，我做到了。
但是当我通过eclipse插件运行gwt时，当我启动应用程序并发送一些数据存储在服务器上时，抛出了这个异常：
Caused by: org.hibernate.HibernateException: Could not instantiate dialect class
at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.constructDialect(DialectFactoryImpl.java:82)
at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:64)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:170)
at org.hibernate.service.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:75)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:159)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131)
at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:71)
at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2273)
at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2269)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1738)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1778)
at web.reg.util.HibernateUtil.<clinit>(HibernateUtil.java:13)
... 28 more
Caused by: java.lang.ClassCastException: org.hibernate.dialect.HSQLDialect cannot be cast to org.hibernate.dialect.Dialect
at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.constructDialect(DialectFactoryImpl.java:73)
我的hibernate.cfg.xml实际上是由属性使用org.hibernate.dialect.HSQLDialect： org.hibernate.dialect.HSQLDialect
the .jar files I'm using are:
on GWT structure:
war/WEB-INF/lib:
|- antlr-2.7.7.jar
|- dom4j-1.6.1.jar
|- gwt-servlet.jar
|- hibernate-commons-annotations-4.0.1.Final.jar
|- hibernate-core-4.1.1.Final.jar
|- hibernate-entitymanager-4.1.1.Final.jar
|- hibernate-jpa-2.0-api-1.0.1.Final.jar
|- hsqldb.jar
|- javassist-3.15.0-GA.jar
|- jboss-logging-3.1.0.GA.jar
|- jboss-transaction-api_1.1_spec-1.0.0.Final.jar
|- jsr107cache-1.1.jar
缺少什么？或者有什么我不应该放的东西？
答案 0 :(得分：0)
我认为@Strelok是对的，似乎你在jar HSQLDB和hibernate.4x之间存在兼容性问题。如果您从谷歌网站下载了集成gwt + hibernate的示例，那么最好检查该示例使用的jar版本，还应检查您是否添加了一些不兼容的jar
答案 1 :(得分：0)
这是一个Jetty类加载器问题。我自己没有得到这个特殊错误，但问题详见Hibernate Bug Report。
Vladimir Konkov建议更改ClassLoaderServiceImpl.java以将null值传递给构造函数应该可以解决它。
this.classClassLoader = new ClassLoader(null) {
@Override
protected Class<?> findClass(String name) throws ClassNotFoundException {
for ( ClassLoader loader : classLoadingClassLoaders ) {
try {
return loader.loadClass( name );
}
catch (Exception ignore) {
}
}
throw new ClassNotFoundException( "Could not load requested class : " + name );
}
};