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Problems connecting to a database

April Pilis
Greenhorn

Joined: Dec 30, 2011
Posts: 4
Hi to all!

This is my first question in this forum, since usually I prefer to find my questions already answered elsewhere, but this time I am desperate and I suspect there might be some simple solution to the problem.
I am new with GWT. Used it once a little time ago. Now I am making a new project and I have problems connecting to a database on localhost. It might a be problem with configuration or me forgetting to include some jar or whatever, because the same line of code works perfectly fine, if I just copy and paste it into my old project.
But as far as I can see, the only differences between the old and the new projects are:
- Eclipse version (which should not be a problem)
- GWT version

This is the line of code causing problems:
"Connection dbConnection=DriverManager.getConnection("jdbc:postgresql://localhost:5433/music", "user", "password");"
The driver class is loaded without any problems with: "Class.forName("org.postgresql.Driver");"
The database name, username and password are correct, since this line works fine in other programs.
For the same reason the database configurations should be ok as well. So I really have no idea, what might be the problem.

I have added postgresql-9.0-901.jdbc4.jar to my buildpath, now it is in the referenced libraries. I have also copied the same jar into war/WEB-INF/lib folder.

The error I get:

com.google.appengine.tools.development.ApiProxyLocalImpl log
SEVERE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String[] recommender.client.RegistrationService.register(java.lang.String[])' threw an unexpected exception: 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.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$ApiProxyHandler.handle(JettyContainerService.java:362)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$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.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.postgresql.core.PGStream.<init>(PGStream.java:62)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:76)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66)
at org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:125)
at org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30)
at org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnection.java:22)
at org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.java:32)
at org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)
at org.postgresql.Driver.makeConnection(Driver.java:393)
at org.postgresql.Driver.connect(Driver.java:267)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at recommender.server.RegistrationServiceImpl.register(RegistrationServiceImpl.java:38)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:100)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
... 34 more


Does anyone have an idea, what might be wrong?

Maneesh Godbole
Saloon Keeper

Joined: Jul 26, 2007
Posts: 10519
    
    9

Welcome to the Ranch.

Looks lie you have created a GWT+GAE project, which does not allow you to use your own DB.

Project->Properties->Google->App Engine (deselect the "Use Google App Engine" check box)
Ensure you got your jars under WEB-INF/lib and they are on the java build path.
Project clean and enjoy


[How to ask questions] [Donate a pint, save a life!] [Onff-turn it on!]
April Pilis
Greenhorn

Joined: Dec 30, 2011
Posts: 4
Thanks Maneesh, that seems to be the problem, since in my old project I had this check-box deselected.

Only now, when I deselect the check-box I cannot run the project as web application.

It gets stuck with the following:

Starting Jetty on port 8888
[WARN] failed org.mortbay.jetty.nio.SelectChannelConnector$1@157fe3d
java.lang.NoSuchMethodError: org.mortbay.thread.Timeout.<init>(Ljava/lang/Object;)V
at org.mortbay.io.nio.SelectorManager$SelectSet.<init>(SelectorManager.java:306)
at org.mortbay.io.nio.SelectorManager.doStart(SelectorManager.java:223)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:303)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.Server.doStart(Server.java:233)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
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)
[WARN] failed SelectChannelConnector@127.0.0.1:8888
java.lang.NoSuchMethodError: org.mortbay.thread.Timeout.<init>(Ljava/lang/Object;)V
at org.mortbay.io.nio.SelectorManager$SelectSet.<init>(SelectorManager.java:306)
at org.mortbay.io.nio.SelectorManager.doStart(SelectorManager.java:223)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:303)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.Server.doStart(Server.java:233)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
at com.google.gwt.dev.DevMode.main(DevMode.java:311)
[WARN] failed Server@1f622fa
java.lang.NoSuchMethodError: org.mortbay.thread.Timeout.<init>(Ljava/lang/Object;)V
at org.mortbay.io.nio.SelectorManager$SelectSet.<init>(SelectorManager.java:306)
at org.mortbay.io.nio.SelectorManager.doStart(SelectorManager.java:223)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:303)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.Server.doStart(Server.java:233)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
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)
Exception in thread "main" java.lang.NoSuchMethodError: org.mortbay.thread.Timeout.<init>(Ljava/lang/Object;)V
at org.mortbay.io.nio.SelectorManager$SelectSet.<init>(SelectorManager.java:306)
at org.mortbay.io.nio.SelectorManager.doStart(SelectorManager.java:223)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:303)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.Server.doStart(Server.java:233)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
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)
April Pilis
Greenhorn

Joined: Dec 30, 2011
Posts: 4
And I have managed to fix it by removing all the unneeded jars from the build path.
Maneesh Godbole
Saloon Keeper

Joined: Jul 26, 2007
Posts: 10519
    
    9

Well done and thank you for sharing the solution here
suresh manda
Greenhorn

Joined: Jan 24, 2013
Posts: 2
Maneesh Godbole wrote:thank you
 
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subject: Problems connecting to a database