RE: More questions on runtime schema generation

2007-04-27 Thread Patrick Linskey
> > 2. It looks like the best strategy for geronimo to follow 
> is to figure 
> > out which jars in an ee app can possibly have persistent classes in 
> > them and supply a list of those jars to the 
> PersistenceUnitInfo.  IIUC 
> > scanning those jars is already implemented.
> 
> IIRC the spec limited the scope of a persistence unit to the 
> jar that contains the persistence.xml file, so we shouldn't 
> have to do deep scanning.

... but the developer can list additional jars in locations relative to
the deployed jar, and the container is responsible for providing
resolvable URLs for those jars via PUInfo.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc.
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> -Original Message-
> From: Dain Sundstrom [mailto:[EMAIL PROTECTED] 
> Sent: Friday, April 27, 2007 9:22 AM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: More questions on runtime schema generation
> 
> On Apr 26, 2007, at 1:49 PM, David Jencks wrote:
> 
> > Thanks for all the comments, I've learned a lot.
> >
> > 1. I have a classloader scanning strategy written and apparently 
> > working, however it is rather slow at least in geronimo.  Is anyone 
> > interested in it, seeing as how its not an appropriate 
> approach in a 
> > app server according to Patrick's comment below?  I think it might 
> > still be useful as a "last resort" strategy.
> >
> > 2. It looks like the best strategy for geronimo to follow 
> is to figure 
> > out which jars in an ee app can possibly have persistent classes in 
> > them and supply a list of those jars to the 
> PersistenceUnitInfo.  IIUC 
> > scanning those jars is already implemented.
> 
> IIRC the spec limited the scope of a persistence unit to the 
> jar that contains the persistence.xml file, so we shouldn't 
> have to do deep scanning.
> 
> > 3. I can't get running ddl on a connection from an XADataSource in  
> > a simulated "RequiresNew" transaction to work reliably with 
> derby.   
> > The ddl appears to work fine but attempts to read data from the 
> > created sequence table hang until the tx times out and 
> derby does not 
> > report any deadlocks.  Based on Craig's comments I've added a 
> > non-jta-datasource and this seems to be working much better.  Has 
> > anyone seen problems like this?  (seems unlikely in this 
> context since 
> > i had to modify a bunch of stuff to get to this problem :-)
> 
> If the outer transaction has previously read from that table, 
> you have created a self deadlock.  Have you checked the sql 
> to make sure that there isn't a query that referenced the 
> sequence table?
> 
> -dain
> 

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Re: More questions on runtime schema generation

2007-04-27 Thread Dain Sundstrom

On Apr 26, 2007, at 1:49 PM, David Jencks wrote:


Thanks for all the comments, I've learned a lot.

1. I have a classloader scanning strategy written and apparently  
working, however it is rather slow at least in geronimo.  Is anyone  
interested in it, seeing as how its not an appropriate approach in  
a app server according to Patrick's comment below?  I think it  
might still be useful as a "last resort" strategy.


2. It looks like the best strategy for geronimo to follow is to  
figure out which jars in an ee app can possibly have persistent  
classes in them and supply a list of those jars to the  
PersistenceUnitInfo.  IIUC scanning those jars is already implemented.


IIRC the spec limited the scope of a persistence unit to the jar that  
contains the persistence.xml file, so we shouldn't have to do deep  
scanning.


3. I can't get running ddl on a connection from an XADataSource in  
a simulated "RequiresNew" transaction to work reliably with derby.   
The ddl appears to work fine but attempts to read data from the  
created sequence table hang until the tx times out and derby does  
not report any deadlocks.  Based on Craig's comments I've added a  
non-jta-datasource and this seems to be working much better.  Has  
anyone seen problems like this?  (seems unlikely in this context  
since i had to modify a bunch of stuff to get to this problem :-)


If the outer transaction has previously read from that table, you  
have created a self deadlock.  Have you checked the sql to make sure  
that there isn't a query that referenced the sequence table?


-dain


RE: More questions on runtime schema generation

2007-04-26 Thread Patrick Linskey
> 1. I have a classloader scanning strategy written and 
> apparently working, however it is rather slow at least in 
> geronimo.  Is anyone interested in it, seeing as how its not 
> an appropriate approach in a app server according to 
> Patrick's comment below?  I think it might still be useful as 
> a "last resort" strategy.

Can you describe it in more detail?

> 2. It looks like the best strategy for geronimo to follow is 
> to figure out which jars in an ee app can possibly have 
> persistent classes in them and supply a list of those jars to 
> the PersistenceUnitInfo.  IIUC scanning those jars is already 
> implemented.

Yes. The easy way to do this is to just include all the jars in the
scope of a given PU (all the jars in the EAR for EAR-scoped; all the
jars in the WAR or EJB-JAR otherwise) in the PUInfo.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc.
___
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or entity named in this message. If you are not the intended recipient,
and have received this message in error, please immediately return this
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> -Original Message-
> From: David Jencks [mailto:[EMAIL PROTECTED] 
> Sent: Thursday, April 26, 2007 1:50 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: More questions on runtime schema generation
> 
> Thanks for all the comments, I've learned a lot.
> 
> 1. I have a classloader scanning strategy written and 
> apparently working, however it is rather slow at least in 
> geronimo.  Is anyone interested in it, seeing as how its not 
> an appropriate approach in a app server according to 
> Patrick's comment below?  I think it might still be useful as 
> a "last resort" strategy.
> 
> 2. It looks like the best strategy for geronimo to follow is 
> to figure out which jars in an ee app can possibly have 
> persistent classes in them and supply a list of those jars to 
> the PersistenceUnitInfo.  IIUC scanning those jars is already 
> implemented.
> 
> 3. I can't get running ddl on a connection from an 
> XADataSource in a simulated "RequiresNew" transaction to work 
> reliably with derby.  The ddl appears to work fine but 
> attempts to read data from the created sequence table hang 
> until the tx times out and derby does not report any 
> deadlocks.  Based on Craig's comments I've added a non-jta- 
> datasource and this seems to be working much better.  Has 
> anyone seen problems like this?  (seems unlikely in this 
> context since i had to modify a bunch of stuff to get to this 
> problem :-)
> 
> many thanks
> david jencks
> 
> On Apr 25, 2007, at 3:56 PM, Patrick Linskey wrote:
> 
> > Inside an appserver, there are parts of the PersistenceUnitInfo 
> > interface that are designed for the appserver to 
> communicate jars to 
> > scan to the persistence provider.
> >
> > -Patrick
> >
> > --
> > Patrick Linskey
> > BEA Systems, Inc.
> > 
> __
> > _
> > Notice:  This email message, together with any attachments, may 
> > contain
> > information  of  BEA Systems,  Inc.,  its subsidiaries  and   
> > affiliated
> > entities,  that may be confidential,  proprietary,  copyrighted   
> > and/or
> > legally privileged, and is intended solely for the use of the 
> > individual or entity named in this message. If you are not the 
> > intended recipient, and have received this message in error, please 
> > immediately return this by email and then delete it.
> >
> >> -Original Message-
> >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> >> Sent: Wednesday, April 25, 2007 3:55 PM
> >> To: open-jpa-dev@incubator.apache.org
> >> Subject: Re: More questions on runtime schema generation
> >>
> >> The general solution to this problem lies in a crisper 
> definition of 
> >> classloader domains in the app server. IIUC, each app 
> server has its 
> >> own policies in terms of where various components get loaded and 
> >> when.
> >>
> >> I think we need to engage the server spec team on this, 
> otherwise we 
> >> will end up chasing multiple incompatible class loader strategies, 
> >> all of which turn out to be spec compliant.
> >>
> >> And 

Re: More questions on runtime schema generation

2007-04-26 Thread David Jencks

Thanks for all the comments, I've learned a lot.

1. I have a classloader scanning strategy written and apparently  
working, however it is rather slow at least in geronimo.  Is anyone  
interested in it, seeing as how its not an appropriate approach in a  
app server according to Patrick's comment below?  I think it might  
still be useful as a "last resort" strategy.


2. It looks like the best strategy for geronimo to follow is to  
figure out which jars in an ee app can possibly have persistent  
classes in them and supply a list of those jars to the  
PersistenceUnitInfo.  IIUC scanning those jars is already implemented.


3. I can't get running ddl on a connection from an XADataSource in a  
simulated "RequiresNew" transaction to work reliably with derby.  The  
ddl appears to work fine but attempts to read data from the created  
sequence table hang until the tx times out and derby does not report  
any deadlocks.  Based on Craig's comments I've added a non-jta- 
datasource and this seems to be working much better.  Has anyone seen  
problems like this?  (seems unlikely in this context since i had to  
modify a bunch of stuff to get to this problem :-)


many thanks
david jencks

On Apr 25, 2007, at 3:56 PM, Patrick Linskey wrote:


Inside an appserver, there are parts of the PersistenceUnitInfo
interface that are designed for the appserver to communicate jars to
scan to the persistence provider.

-Patrick

--
Patrick Linskey
BEA Systems, Inc.
__ 
_
Notice:  This email message, together with any attachments, may  
contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and   
affiliated
entities,  that may be confidential,  proprietary,  copyrighted   
and/or
legally privileged, and is intended solely for the use of the  
individual
or entity named in this message. If you are not the intended  
recipient,
and have received this message in error, please immediately return  
this

by email and then delete it.


-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Wednesday, April 25, 2007 3:55 PM
To: open-jpa-dev@incubator.apache.org
Subject: Re: More questions on runtime schema generation

The general solution to this problem lies in a crisper
definition of classloader domains in the app server. IIUC,
each app server has its own policies in terms of where
various components get loaded and when.

I think we need to engage the server spec team on this,
otherwise we will end up chasing multiple incompatible class
loader strategies, all of which turn out to be spec compliant.

And for a first cut at "reasonable" we might ask the Spring
folks how they handle this.

Craig

On Apr 25, 2007, at 12:26 PM, Patrick Linskey wrote:


However IIUC this dissects the system property java.class.path and
only parses stuff on that.  This might be reasonable for a command
line tool (although I have some
doubts) but it seems to me that for any other situation a

scan of the

provided classloader would be more appropriate.
Is this reasonable?


It is. Of course, there is no standard way to scan

classloaders. The

best I know of is to do:

cls.getProtectionDomain().getCodeSource().getLocation()

and then scan from that URL.

Of course, this assumes that a) you have a class (not a

ClassLoader),

b) you have security privileges to get the protection

domain, and b)

the location is parsable and accessible.

Is there some other way that you know of to scan a ClassLoader?


Also, I would like to suggest a flag in the
openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to turn on
this eager scanning I'm trying to implement.  Does this seem
reasonable?


It does.

--
Patrick Linskey
BEA Systems, Inc.

_ 
_

_
Notice:  This email message, together with any attachments, may
contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and
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entities,  that may be confidential,  proprietary,  copyrighted
and/or
legally privileged, and is intended solely for the use of the
individual or entity named in this message. If you are not the
intended recipient, and have received this message in error, please
immediately return this by email and then delete it.


-Original Message-
From: David Jencks [mailto:[EMAIL PROTECTED]
Sent: Wednesday, April 25, 2007 12:18 PM
To: open-jpa-dev@incubator.apache.org
Subject: More questions on runtime schema generation

I'm working on modifications so that ddl can operate in a separate
transaction on a connection from the jta ds and I would

like to have

a complete scan and enhancement as soon as possible when

the EMF is

first accessed.  I have this working when the classes are listed
explicitly in the persistence.xml but not when they aren't.

It looks like the relevant code is AbstractCFMetaDataFactory
getPersistentTypeNames


RE: More questions on runtime schema generation

2007-04-25 Thread Patrick Linskey
Inside an appserver, there are parts of the PersistenceUnitInfo
interface that are designed for the appserver to communicate jars to
scan to the persistence provider.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc.
___
Notice:  This email message, together with any attachments, may contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and  affiliated
entities,  that may be confidential,  proprietary,  copyrighted  and/or
legally privileged, and is intended solely for the use of the individual
or entity named in this message. If you are not the intended recipient,
and have received this message in error, please immediately return this
by email and then delete it. 

> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
> Sent: Wednesday, April 25, 2007 3:55 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: More questions on runtime schema generation
> 
> The general solution to this problem lies in a crisper 
> definition of classloader domains in the app server. IIUC, 
> each app server has its own policies in terms of where 
> various components get loaded and when.
> 
> I think we need to engage the server spec team on this, 
> otherwise we will end up chasing multiple incompatible class 
> loader strategies, all of which turn out to be spec compliant.
> 
> And for a first cut at "reasonable" we might ask the Spring 
> folks how they handle this.
> 
> Craig
> 
> On Apr 25, 2007, at 12:26 PM, Patrick Linskey wrote:
> 
> >> However IIUC this dissects the system property java.class.path and 
> >> only parses stuff on that.  This might be reasonable for a command 
> >> line tool (although I have some
> >> doubts) but it seems to me that for any other situation a 
> scan of the 
> >> provided classloader would be more appropriate.
> >> Is this reasonable?
> >
> > It is. Of course, there is no standard way to scan 
> classloaders. The 
> > best I know of is to do:
> >
> > cls.getProtectionDomain().getCodeSource().getLocation()
> >
> > and then scan from that URL.
> >
> > Of course, this assumes that a) you have a class (not a 
> ClassLoader), 
> > b) you have security privileges to get the protection 
> domain, and b) 
> > the location is parsable and accessible.
> >
> > Is there some other way that you know of to scan a ClassLoader?
> >
> >> Also, I would like to suggest a flag in the
> >> openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to turn on 
> >> this eager scanning I'm trying to implement.  Does this seem 
> >> reasonable?
> >
> > It does.
> >
> > --
> > Patrick Linskey
> > BEA Systems, Inc.
> > 
> __
> > _
> > Notice:  This email message, together with any attachments, may 
> > contain
> > information  of  BEA Systems,  Inc.,  its subsidiaries  and   
> > affiliated
> > entities,  that may be confidential,  proprietary,  copyrighted   
> > and/or
> > legally privileged, and is intended solely for the use of the 
> > individual or entity named in this message. If you are not the 
> > intended recipient, and have received this message in error, please 
> > immediately return this by email and then delete it.
> >
> >> -Original Message-
> >> From: David Jencks [mailto:[EMAIL PROTECTED]
> >> Sent: Wednesday, April 25, 2007 12:18 PM
> >> To: open-jpa-dev@incubator.apache.org
> >> Subject: More questions on runtime schema generation
> >>
> >> I'm working on modifications so that ddl can operate in a separate 
> >> transaction on a connection from the jta ds and I would 
> like to have 
> >> a complete scan and enhancement as soon as possible when 
> the EMF is 
> >> first accessed.  I have this working when the classes are listed 
> >> explicitly in the persistence.xml but not when they aren't.
> >>
> >> It looks like the relevant code is AbstractCFMetaDataFactory 
> >> getPersistentTypeNames
> >>
> >>  if (names.isEmpty() && devpath)
> >>  scan(new ClasspathMetaDataIterator(null, 
> >> newMetaDataFilter()),
> >>  newClassArgParser(), names, false, null);
> >>
> >>
> >> However IIUC this dissects the system property java.class.path and 
> >> only parses stuff on that.  This might be reasonable for a command 
> >> line tool (although I hav

Re: More questions on runtime schema generation

2007-04-25 Thread Craig L Russell
The general solution to this problem lies in a crisper definition of  
classloader domains in the app server. IIUC, each app server has its  
own policies in terms of where various components get loaded and when.


I think we need to engage the server spec team on this, otherwise we  
will end up chasing multiple incompatible class loader strategies,  
all of which turn out to be spec compliant.


And for a first cut at "reasonable" we might ask the Spring folks how  
they handle this.


Craig

On Apr 25, 2007, at 12:26 PM, Patrick Linskey wrote:


However IIUC this dissects the system property
java.class.path and only parses stuff on that.  This might be
reasonable for a command line tool (although I have some
doubts) but it seems to me that for any other situation a
scan of the provided classloader would be more appropriate.
Is this reasonable?


It is. Of course, there is no standard way to scan classloaders. The
best I know of is to do:

cls.getProtectionDomain().getCodeSource().getLocation()

and then scan from that URL.

Of course, this assumes that a) you have a class (not a  
ClassLoader), b)

you have security privileges to get the protection domain, and b) the
location is parsable and accessible.

Is there some other way that you know of to scan a ClassLoader?


Also, I would like to suggest a flag in the
openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to
turn on this eager scanning I'm trying to implement.  Does
this seem reasonable?


It does.

--
Patrick Linskey
BEA Systems, Inc.
__ 
_
Notice:  This email message, together with any attachments, may  
contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and   
affiliated
entities,  that may be confidential,  proprietary,  copyrighted   
and/or
legally privileged, and is intended solely for the use of the  
individual
or entity named in this message. If you are not the intended  
recipient,
and have received this message in error, please immediately return  
this

by email and then delete it.


-Original Message-
From: David Jencks [mailto:[EMAIL PROTECTED]
Sent: Wednesday, April 25, 2007 12:18 PM
To: open-jpa-dev@incubator.apache.org
Subject: More questions on runtime schema generation

I'm working on modifications so that ddl can operate in a
separate transaction on a connection from the jta ds and I
would like to have a complete scan and enhancement as soon as
possible when the EMF is first accessed.  I have this working
when the classes are listed explicitly in the persistence.xml
but not when they aren't.

It looks like the relevant code is AbstractCFMetaDataFactory
getPersistentTypeNames

 if (names.isEmpty() && devpath)
 scan(new ClasspathMetaDataIterator(null,
newMetaDataFilter()),
 newClassArgParser(), names, false, null);


However IIUC this dissects the system property
java.class.path and only parses stuff on that.  This might be
reasonable for a command line tool (although I have some
doubts) but it seems to me that for any other situation a
scan of the provided classloader would be more appropriate.
Is this reasonable?

Also, I would like to suggest a flag in the
openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to
turn on this eager scanning I'm trying to implement.  Does
this seem reasonable?

thanks
david jencks





Notice:  This email message, together with any attachments, may  
contain information  of  BEA Systems,  Inc.,  its subsidiaries   
and  affiliated entities,  that may be confidential,  proprietary,   
copyrighted  and/or legally privileged, and is intended solely for  
the use of the individual or entity named in this message. If you  
are not the intended recipient, and have received this message in  
error, please immediately return this by email and then delete it.


Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!



smime.p7s
Description: S/MIME cryptographic signature


RE: More questions on runtime schema generation

2007-04-25 Thread Patrick Linskey
OpenJPA actually already has jar-scanning code. Try the following:

openjpa.jdbc.SynchronizeMappings:
buildSchema(files=path/to/file.jar;path/to/another-file.jar)

You can also specify 'resources' or 'URLs'.

These algorithms use
org.apache.openjpa.lib.meta.ClassAnnotationMetaDataFilter, which scans
bytes for specified annotations. IIRC, we looked at some Apache code
when implementing it; I can't remember if it was xbean code or not.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc.
___
Notice:  This email message, together with any attachments, may contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and  affiliated
entities,  that may be confidential,  proprietary,  copyrighted  and/or
legally privileged, and is intended solely for the use of the individual
or entity named in this message. If you are not the intended recipient,
and have received this message in error, please immediately return this
by email and then delete it. 

> -Original Message-
> From: David Jencks [mailto:[EMAIL PROTECTED] 
> Sent: Wednesday, April 25, 2007 12:42 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: More questions on runtime schema generation
> 
> 
> On Apr 25, 2007, at 12:26 PM, Patrick Linskey wrote:
> 
> >> However IIUC this dissects the system property java.class.path and 
> >> only parses stuff on that.  This might be reasonable for a command 
> >> line tool (although I have some
> >> doubts) but it seems to me that for any other situation a 
> scan of the 
> >> provided classloader would be more appropriate.
> >> Is this reasonable?
> >
> > It is. Of course, there is no standard way to scan 
> classloaders. The 
> > best I know of is to do:
> >
> > cls.getProtectionDomain().getCodeSource().getLocation()
> >
> > and then scan from that URL.
> >
> > Of course, this assumes that a) you have a class (not a 
> ClassLoader), 
> > b) you have security privileges to get the protection 
> domain, and b) 
> > the location is parsable and accessible.
> >
> > Is there some other way that you know of to scan a ClassLoader?
> 
> I was going to steal code from xbean ClassFinder
> 
> https://svn.apache.org/repos/asf/geronimo/xbean/trunk/xbean-finder/
> src/main/java/org/apache/xbean/finder/ClassFinder.java
> 
> which works for jar files, which is all I'm interested in.  
> It locates the jar or directory or an exploded jar by looking 
> for all the META-INF resources in the classloader.  This 
> isn't exactly scanning a classloader but will be adequate for me.
> 
> I don't suppose openjpa would be interested in using the 
> xbean-finder jar directly?  It only has 3 classes in it :-)  
> In particular ClassFinder is good at locating all the classes 
> with an annotation in a classloader.
> 
> thanks
> david jencks
> 
> 
> >
> >> Also, I would like to suggest a flag in the
> >> openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to turn on 
> >> this eager scanning I'm trying to implement.  Does this seem 
> >> reasonable?
> >
> > It does.
> >
> > --
> > Patrick Linskey
> > BEA Systems, Inc.
> > 
> __
> > _
> > Notice:  This email message, together with any attachments, may 
> > contain
> > information  of  BEA Systems,  Inc.,  its subsidiaries  and   
> > affiliated
> > entities,  that may be confidential,  proprietary,  copyrighted   
> > and/or
> > legally privileged, and is intended solely for the use of the 
> > individual or entity named in this message. If you are not the 
> > intended recipient, and have received this message in error, please 
> > immediately return this by email and then delete it.
> >
> >> -Original Message-
> >> From: David Jencks [mailto:[EMAIL PROTECTED]
> >> Sent: Wednesday, April 25, 2007 12:18 PM
> >> To: open-jpa-dev@incubator.apache.org
> >> Subject: More questions on runtime schema generation
> >>
> >> I'm working on modifications so that ddl can operate in a separate 
> >> transaction on a connection from the jta ds and I would 
> like to have 
> >> a complete scan and enhancement as soon as possible when 
> the EMF is 
> >> first accessed.  I have this working when the classes are listed 
> >> explicitly in the persistence.xml but not when they aren't.
> >>
> >> It looks like the relevant code is AbstractCFMetaDataFactory 
> >> getPersistentTypeNames
&

Re: More questions on runtime schema generation

2007-04-25 Thread David Jencks


On Apr 25, 2007, at 12:26 PM, Patrick Linskey wrote:


However IIUC this dissects the system property
java.class.path and only parses stuff on that.  This might be
reasonable for a command line tool (although I have some
doubts) but it seems to me that for any other situation a
scan of the provided classloader would be more appropriate.
Is this reasonable?


It is. Of course, there is no standard way to scan classloaders. The
best I know of is to do:

cls.getProtectionDomain().getCodeSource().getLocation()

and then scan from that URL.

Of course, this assumes that a) you have a class (not a  
ClassLoader), b)

you have security privileges to get the protection domain, and b) the
location is parsable and accessible.

Is there some other way that you know of to scan a ClassLoader?


I was going to steal code from xbean ClassFinder

https://svn.apache.org/repos/asf/geronimo/xbean/trunk/xbean-finder/ 
src/main/java/org/apache/xbean/finder/ClassFinder.java


which works for jar files, which is all I'm interested in.  It  
locates the jar or directory or an exploded jar by looking for all  
the META-INF resources in the classloader.  This isn't exactly  
scanning a classloader but will be adequate for me.


I don't suppose openjpa would be interested in using the xbean-finder  
jar directly?  It only has 3 classes in it :-)  In particular  
ClassFinder is good at locating all the classes with an annotation in  
a classloader.


thanks
david jencks





Also, I would like to suggest a flag in the
openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to
turn on this eager scanning I'm trying to implement.  Does
this seem reasonable?


It does.

--
Patrick Linskey
BEA Systems, Inc.
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-Original Message-
From: David Jencks [mailto:[EMAIL PROTECTED]
Sent: Wednesday, April 25, 2007 12:18 PM
To: open-jpa-dev@incubator.apache.org
Subject: More questions on runtime schema generation

I'm working on modifications so that ddl can operate in a
separate transaction on a connection from the jta ds and I
would like to have a complete scan and enhancement as soon as
possible when the EMF is first accessed.  I have this working
when the classes are listed explicitly in the persistence.xml
but not when they aren't.

It looks like the relevant code is AbstractCFMetaDataFactory
getPersistentTypeNames

 if (names.isEmpty() && devpath)
 scan(new ClasspathMetaDataIterator(null,
newMetaDataFilter()),
 newClassArgParser(), names, false, null);


However IIUC this dissects the system property
java.class.path and only parses stuff on that.  This might be
reasonable for a command line tool (although I have some
doubts) but it seems to me that for any other situation a
scan of the provided classloader would be more appropriate.
Is this reasonable?

Also, I would like to suggest a flag in the
openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to
turn on this eager scanning I'm trying to implement.  Does
this seem reasonable?

thanks
david jencks





Notice:  This email message, together with any attachments, may  
contain information  of  BEA Systems,  Inc.,  its subsidiaries   
and  affiliated entities,  that may be confidential,  proprietary,   
copyrighted  and/or legally privileged, and is intended solely for  
the use of the individual or entity named in this message. If you  
are not the intended recipient, and have received this message in  
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RE: More questions on runtime schema generation

2007-04-25 Thread Patrick Linskey
> However IIUC this dissects the system property 
> java.class.path and only parses stuff on that.  This might be 
> reasonable for a command line tool (although I have some 
> doubts) but it seems to me that for any other situation a 
> scan of the provided classloader would be more appropriate.  
> Is this reasonable?

It is. Of course, there is no standard way to scan classloaders. The
best I know of is to do:

cls.getProtectionDomain().getCodeSource().getLocation()

and then scan from that URL.

Of course, this assumes that a) you have a class (not a ClassLoader), b)
you have security privileges to get the protection domain, and b) the
location is parsable and accessible.

Is there some other way that you know of to scan a ClassLoader?

> Also, I would like to suggest a flag in the
> openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to 
> turn on this eager scanning I'm trying to implement.  Does 
> this seem reasonable?

It does.

-- 
Patrick Linskey
BEA Systems, Inc.
___
Notice:  This email message, together with any attachments, may contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and  affiliated
entities,  that may be confidential,  proprietary,  copyrighted  and/or
legally privileged, and is intended solely for the use of the individual
or entity named in this message. If you are not the intended recipient,
and have received this message in error, please immediately return this
by email and then delete it. 

> -Original Message-
> From: David Jencks [mailto:[EMAIL PROTECTED] 
> Sent: Wednesday, April 25, 2007 12:18 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: More questions on runtime schema generation
> 
> I'm working on modifications so that ddl can operate in a 
> separate transaction on a connection from the jta ds and I 
> would like to have a complete scan and enhancement as soon as 
> possible when the EMF is first accessed.  I have this working 
> when the classes are listed explicitly in the persistence.xml 
> but not when they aren't.
> 
> It looks like the relevant code is AbstractCFMetaDataFactory 
> getPersistentTypeNames
> 
>  if (names.isEmpty() && devpath)
>  scan(new ClasspathMetaDataIterator(null, 
> newMetaDataFilter()),
>  newClassArgParser(), names, false, null);
> 
> 
> However IIUC this dissects the system property 
> java.class.path and only parses stuff on that.  This might be 
> reasonable for a command line tool (although I have some 
> doubts) but it seems to me that for any other situation a 
> scan of the provided classloader would be more appropriate.  
> Is this reasonable?
> 
> Also, I would like to suggest a flag in the
> openjpa.jdbc.SynchronizeMappings=buildSchema(...) stuff to 
> turn on this eager scanning I'm trying to implement.  Does 
> this seem reasonable?
> 
> thanks
> david jencks
> 
> 
> 

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this message in error, please immediately return this by email and then delete 
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