[rules-dev] Drools in Google App Engine
Paul Browne
paulb at firstpartners.net
Fri May 15 17:40:52 EDT 2009
Ok, for the moment I'll use either AspectJ or modify the source (i.e. it can
get pasts the File.exists() so that I can identify all of points that App
engine doesn't like ....
On Fri, May 15, 2009 at 9:16 AM, Geoffrey De Smet
<ge0ffrey.spam at gmail.com>wrote:
> I am not surprised that File.exists() fails, but why does
> getClass().getResourceAsStream() fail?
>
> In Applets, the latter should work:
> http://java.sun.com/docs/books/tutorial/uiswing/components/applet.html
> chapter Using Images in a Swing Applet.
>
> Because getClass().getResourceAsStream() only looks in the classpath,
> I see not reason that Google App Engine would block it.
>
> With kind regards,
> Geoffrey De Smet
>
>
> Paul Browne schreef:
>
>> Geoffrey,
>> The stack exception below is Drools looking for the conf file *before* it
>> even looks for the DRL file. However *any* file IO is blocked - so even it
>> Drools got past the File.exists(), it's likely to throw another
>> SecurityException at the getClass().getResourceAsStream for the DRL file.
>> I say 'likely' as 3 months ago I was trying to get version 4 of Drools
>> running in an Applet environment (has similar security constraints), and
>> worked my way through the source code to resolve the security exceptions. In
>> that case, getClass().getResourceAsStream was blocked.
>> Any suggestions?
>> Thanks
>> Paul
>>
>>
>> On Wed, May 13, 2009 at 4:51 PM, Geoffrey De Smet <
>> ge0ffrey.spam at gmail.com <mailto:ge0ffrey.spam at gmail.com>> wrote:
>>
>> Does this File.exists() usage occur even if your DRL is a classpath
>> resource and fetched with getClass().getResourceAsStream()?
>>
>> With kind regards,
>> Geoffrey De Smet
>>
>>
>> Paul Browne schreef:
>>
>> Folks,
>>
>> Are there any plans to tweak Drools to allow it to run in a
>> security constrained environment such as Google App Engine or
>> Applets? I know some of the other JBoss.org projects have this
>> on the 'todo' list.
>>
>> When I try to load a simple web application using drools into
>> the Google App Engine, I get the error below.The app itself is
>> the sample 8 from the following web page, but tweaked according
>> to the Google 'howto' to get it up and running in the app
>> engine; http://code.google.com/p/red-piranha/
>>
>> My understanding of the problem is that drools is using File
>> access to check if the configuration file exists the first time
>> it is run. This is constrained in App Engine - just like the
>> J2EE spec says it should be (although most other app servers
>> allow you to get away with this!). I know that if I tweak the
>> source code there will be other points where similar file access
>> is required.
>>
>> While not trivial, would it be possible to add a one-line check
>> for that the user has permission to do file.io <http://file.io/>
>> <http://file.io <http://file.io/>> before calling File.Exists
>>
>> (the alternative , of catching and ignoring the
>> AccessControlException is ugly!). The hardest part of this is
>> that the check would need to be added at multiple points in the
>> Drools source code.
>>
>>
>> Any thoughts / comments/ suggestions?
>>
>> Paul
>>
>> www.firstpartners.net/blog <http://www.firstpartners.net/blog>
>> <http://www.firstpartners.net/blog>
>>
>>
>>
>> WARNING: java.security.AccessControlException: access denied
>> (java.io.FilePermission /home/paul/drools.rulebase.conf read)
>> 13-May-2009 09:04:16
>> com.google.apphosting.utils.jetty.JettyLogger warn
>> WARNING: Nested in javax.servlet.ServletException:
>> java.security.AccessControlException: access denied
>> (java.io.FilePermission /home/paul/drools.rulebase.conf read):
>> java.security.AccessControlException: access denied
>> (java.io.FilePermission /home/paul/drools.rulebase.conf read)
>> 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$CustomSecurityManager.checkPermission(DevAppServerFactory.java:76)
>> at java.lang.SecurityManager.checkRead(SecurityManager.java:871)
>> at java.io.File.exists(File.java:731)
>> at
>>
>> org.drools.util.ChainedProperties.loadProperties(ChainedProperties.java:225)
>> at
>> org.drools.util.ChainedProperties.<init>(ChainedProperties.java:59)
>> at
>> org.drools.util.ChainedProperties.<init>(ChainedProperties.java:31)
>> at
>> org.drools.util.ChainedProperties.<init>(ChainedProperties.java:25)
>> at
>>
>> org.drools.RuleBaseConfiguration.init(RuleBaseConfiguration.java:174)
>> at
>>
>> org.drools.RuleBaseConfiguration.<init>(RuleBaseConfiguration.java:133)
>> at
>>
>> org.drools.common.AbstractRuleBase.<init>(AbstractRuleBase.java:147)
>> at
>> org.drools.reteoo.ReteooRuleBase.<init>(ReteooRuleBase.java:124)
>> at
>> org.drools.reteoo.ReteooRuleBase.<init>(ReteooRuleBase.java:101)
>> at
>> org.drools.RuleBaseFactory.newRuleBase(RuleBaseFactory.java:57)
>> at
>> org.drools.RuleBaseFactory.newRuleBase(RuleBaseFactory.java:38)
>> at
>> net.firstpartners.drools.RuleRunner.loadRules(RuleRunner.java:39)
>> at
>>
>> net.firstpartners.drools.RuleRunner.runStatelessRules(RuleRunner.java:167)
>> at
>> net.firstpartners.rp2.rp2Servlet.callRules(rp2Servlet.java:96)
>> at net.firstpartners.rp2.rp2Servlet.service(rp2Servlet.java:137)
>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
>> at
>>
>> org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
>> at
>>
>> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
>> at
>>
>> com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
>> at
>>
>> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
>> at
>>
>> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
>> at
>>
>> org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
>> at
>>
>> org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
>> at
>>
>> org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:712)
>> at
>>
>> org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
>> at
>>
>> com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:54)
>> at
>>
>> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
>> at
>>
>> com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:306)
>> 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$RequestHandler.headerComplete(HttpConnection.java:830)
>> at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
>> at
>> org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
>> at
>> org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
>> at
>>
>> org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
>> at
>>
>> org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)
>>
>>
>>
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>>
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