CODEWITHSUNDEEP
javagwtgwt-rpc
Dan Inactive
Dan Inactive

Reputation: 10060

GWT: Timer causes runtime warning

I'm working on my first GWT-based Java project for a school assignment. It's a chat application and the client polls the server for new events, while the server keeps an timer for each user to detect inactivity.

The following problem occurs at runtime:

Dec 8, 2009 7:41:17 PM com.google.apphosting.utils.jetty.JettyLogger warn
WARNING: /GAEChat/chat
java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkPermission(DevAppServerFactory.java:151)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkAccess(DevAppServerFactory.java:176)
    at java.lang.ThreadGroup.checkAccess(Unknown Source)
    at java.lang.Thread.init(Unknown Source)
    at java.lang.Thread.<init>(Unknown Source)
    at java.util.TimerThread.<init>(Unknown Source)
    at java.util.Timer.<init>(Unknown Source)
    at java.util.Timer.<init>(Unknown Source)
    at gaechat.server.ChatServiceImpl.<init>(ChatServiceImpl.java:22)
    at sun.reflect.GeneratedConstructorAccessor14.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    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$CachedChain.doFilter(ServletHandler.java:1093)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$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$RequestHandler.content(HttpConnection.java:844)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:205)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
    at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)

Here's the code repository. The problem seems to be in server/ChatServiceImpl.java.

Am I doing something wrong? I'm stuck.

Upvotes: 1

Views: 1088

Answers (2)

Luke
Luke

Reputation: 931

If you are trying to run the servlet application on Google App Engine, which the stack trace seems to show that you are, then you cannot create new threads. App Engine does not allow it.

Upvotes: 0

Iker Jimenez
Iker Jimenez

Reputation: 7245

As this is a school assignment try disabling the SecurityManager first.

Updated: It should be disabled unless you had a -Djava.security.manager set somewhere. See How to disable Java security manager?

BTW, you might be interested in this link ;) The page has the source code available for download.

Upvotes: 2

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