Trying to resolve memory exception through correct use of page se quencing

[John Bourke <jo...@Cedar.com>]

Hi,
I'm having a problem rendering a large file (500 plus pages) using FOP. Fop
eventually causes my machine to run out of memory even though I'm allocating
it 300mb.
I think the problem is caused by me having a page sequence called detail
page, into which my 500 pages worth of data is placed with a page break
before each page full. BUT, this is all within the one page sequence which I
think FOP is trying to render all at once.
Ideally for each page full I would like to start a new page sequence and
thus allow FOP only render one page at a time. Does this sound to anybody
like the right way to go about this?

My page sequence master is as follows:
<fo:page-sequence-master master-name="reportDetails">
    <fo:repeatable-page-master-reference master-name="detailPage"/>
</fo:page-sequence-master>

I then start my page using:
<fo:page-sequence master-reference="reportDetails" initial-page-number="2">

Then when rendering FOP throws the following exception:
---------
java.lang.NullPointerException
at
org.apache.fop.fo.pagination.PageSequence.getNextPageMaster(PageSequence.jav
a:526)
at org.apache.fop.fo.pagination.PageSequence.makePage(PageSequence.java:334)
at org.apache.fop.fo.pagination.PageSequence.format(PageSequence.java:268)
at org.apache.fop.apps.StreamRenderer.render(StreamRenderer.java:200)
at org.apache.fop.fo.FOTreeBuilder.endElement(FOTreeBuilder.java:182)
at org.apache.xerces.parsers.SAXParser.endElement(SAXParser.java:1403)
at
org.apache.xerces.validators.common.XMLValidator.callEndElement(XMLValidator
.java:1550)
at
org.apache.xerces.framework.XMLDocumentScanner$ContentDispatcher.dispatch(XM
LDocumentScanner.java:1204)
at
org.apache.xerces.framework.XMLDocumentScanner.parseSome(XMLDocumentScanner.
java:381)
at org.apache.xerces.framework.XMLParser.parse(XMLParser.java:1098)
at org.apache.fop.apps.Driver.render(Driver.java:481)
at org.apache.fop.apps.Driver.run(Driver.java:554)


Apologies for the length of this message but can anybody advise me?

Best Regards,

John Bourke


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Re: Trying to resolve memory exception through correct use of page se quencing

["Peter B. West" <pb...@powerup.com.au>]

John,

Yes, minimising page-sequence length will reduce memory consumption.

Peter

John Bourke wrote:

>Ideally for each page full I would like to start a new page sequence and
>thus allow FOP only render one page at a time. Does this sound to anybody
>like the right way to go about this?
>
>  
>

Re: Trying to resolve memory exception through correct use of page se quencing

["J.Pietschmann" <j3...@yahoo.de>]

John Bourke wrote:
> I think the problem is caused by me having a page sequence called detail
> page, into which my 500 pages worth of data is placed with a page break
> before each page full. BUT, this is all within the one page sequence which I
> think FOP is trying to render all at once.

FOP tries to render page by page, however, ending a
page sequence will usually free additional memory
(perhaps a lot of additional memory, according to
the stories on the list).

> Then when rendering FOP throws the following exception:
> ---------
> java.lang.NullPointerException
> at
> org.apache.fop.fo.pagination.PageSequence.getNextPageMaster(PageSequence.jav
> a:526)

This has nothing to do with a memory problem. You
probably have referenced a page master which doesn't
exist, or hit another FOP bug. Can you post your
layout-master-set?


J.Pietschmann