GWT 连接数据库问题解决及例子

      最近在搞GWT，之前一直是写Client端的代码，没有和Service端交互过，现在利用GWT的RPC机制和Server端交互，并且连接Oracle数据库，随便写了一个RPC的例子，跑得还挺顺畅，后来就加了连接数据库的语句就怎么也跑不通，不知道出了什么问题，在网上也找了些资料，也按照上面的方式做了，可报出的错误还是一样，错误如下：

 

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 oracle.net.nt.TcpNTAdapter.connect(Unknown Source)
    at oracle.net.nt.ConnOption.connect(Unknown Source)
    at oracle.net.nt.ConnStrategy.execute(Unknown Source)
    at oracle.net.resolver.AddrResolution.resolveAndExecute(Unknown Source)
    at oracle.net.ns.NSProtocol.establishConnection(Unknown Source)
    at oracle.net.ns.NSProtocol.connect(Unknown Source)
    at oracle.jdbc.ttc7.TTC7Protocol.connect(TTC7Protocol.java:1687)
    at oracle.jdbc.ttc7.TTC7Protocol.logon(TTC7Protocol.java:214)
    at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:346)
    at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:468)
    at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:314)
    at java.sql.DriverManager.getConnection(DriverManager.java:582)
    at java.sql.DriverManager.getConnection(DriverManager.java:185)
    at com.founder.employeegwt.utils.DBConnection.getConnection(DBConnection.java:17)
    at com.founder.employeegwt.server.EmployeeServiceImpl.<init>(EmployeeServiceImpl.java:22)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at java.lang.Class.newInstance0(Class.java:355)
    at java.lang.Class.newInstance(Class.java:308)
    at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
    at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:463)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:51)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:121)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:712)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
    at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:352)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
    at org.mortbay.jetty.Server.handle(Server.java:313)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:844)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
    at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)
2010-1-19 10:16:17 com.google.apphosting.utils.jetty.JettyLogger warn
警告: /employeegwt/employee
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 oracle.net.nt.TcpNTAdapter.connect(Unknown Source)
    at oracle.net.nt.ConnOption.connect(Unknown Source)
    at oracle.net.nt.ConnStrategy.execute(Unknown Source)
    at oracle.net.resolver.AddrResolution.resolveAndExecute(Unknown Source)
    at oracle.net.ns.NSProtocol.establishConnection(Unknown Source)
    at oracle.net.ns.NSProtocol.connect(Unknown Source)
    at oracle.jdbc.ttc7.TTC7Protocol.connect(TTC7Protocol.java:1687)
    at oracle.jdbc.ttc7.TTC7Protocol.logon(TTC7Protocol.java:214)
    at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:346)
    at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:468)
    at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:314)
    at java.sql.DriverManager.getConnection(DriverManager.java:582)
    at java.sql.DriverManager.getConnection(DriverManager.java:185)
    at com.founder.employeegwt.utils.DBConnection.getConnection(DBConnection.java:17)
    at com.founder.employeegwt.server.EmployeeServiceImpl.<init>(EmployeeServiceImpl.java:22)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at java.lang.Class.newInstance0(Class.java:355)
    at java.lang.Class.newInstance(Class.java:308)
    at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
    at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:463)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:51)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:121)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:712)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
    at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:352)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
    at org.mortbay.jetty.Server.handle(Server.java:313)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:844)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
    at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)

 

 

找了很多解决方法 就是搞不定，后来把它编译放在Tomcat下跑，竟然可以，后来经过多方查找，竟然发现不能使用GWT App Angine，就做了以下设置：

选择项目右键->Google->App Angine Settings...->Use Google App Engine复选框，把对勾给去掉，就可以了！

下面把我的一个GWT连接数据库的例子加在附件上，可以跑通的！

 

评论

3 楼 Mr.TianShu 2013-03-20  

BAE也出现这问题。。暂时没解决。。肯定是沙盒运行中的限制。

2 楼 smiky 2010-01-22  

MS是权限问题,我也碰到这个问题了,你看gwt官方的demo,说明了布署到tomcat时要对相应的servlet进行grant相应的权限,你这不能算是解决问题的方案吧

1 楼 yonglin4605 2010-01-19  

GAE会对class文件进行增强修改，如果不是在GAE上运行，在创建GWT项目时就不要开启GAE
这种增强是给google自己的面向对象数据库用的