java为什么FOP在大文件上崩溃？

Question

我们在Fop上打印。0.9.4. Windows10系统。Xml文件大小为1.5mb（不是很大）

在该结构的xml文件中：

<root>
 <element />
 <element />
 <element />
 <element />
... 3000 elements or more
</root>

我们在xslt文件中编写

<for-each select="root/element">
 <block-container>
  <some-simple-elements>
 </block-container>
</for-each>

如果页数小于500，则会执行fop，但如果打印量大于等于501页，则会崩溃

在日志中：

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Unknown Source)
at java.lang.AbstractStringBuilder.ensureCapacityInternal(Unknown Source)
at java.lang.AbstractStringBuilder.append(Unknown Source)
at java.lang.StringBuffer.append(Unknown Source)
at org.apache.fop.layoutmgr.AbstractLayoutManager.addChildLM(AbstractLayoutManager.java:317)
at org.apache.fop.layoutmgr.AbstractLayoutManager.addChildLMs(AbstractLayoutManager.java:331)
at org.apache.fop.layoutmgr.AbstractLayoutManager.createNextChildLMs(AbstractLayoutManager.java:291)
at org.apache.fop.layoutmgr.LMiter.hasNext(LMiter.java:40)
at org.apache.fop.layoutmgr.AbstractLayoutManager.getChildLM(AbstractLayoutManager.java:115)
at org.apache.fop.layoutmgr.table.TableCellLayoutManager.getNextKnuthElements(TableCellLayoutManager.java:162)
at org.apache.fop.layoutmgr.table.TableContentLayoutManager.createElementsForRowGroup(TableContentLayoutManager.java:490)
at org.apache.fop.layoutmgr.table.TableContentLayoutManager.getKnuthElementsForRowIterator(TableContentLayoutManager.java:251)
at org.apache.fop.layoutmgr.table.TableContentLayoutManager.getNextKnuthElements(TableContentLayoutManager.java:179)
at org.apache.fop.layoutmgr.table.TableLayoutManager.getNextKnuthElements(TableLayoutManager.java:243)
at org.apache.fop.layoutmgr.BlockContainerLayoutManager$BlockContainerBreaker.getNextKnuthElements(BlockContainerLayoutManager.java:612)
at org.apache.fop.layoutmgr.AbstractBreaker.getNextBlockList(AbstractBreaker.java:551)
at org.apache.fop.layoutmgr.AbstractBreaker.doLayout(AbstractBreaker.java:301)
at org.apache.fop.layoutmgr.BlockContainerLayoutManager.getNextKnuthElementsAbsolute(BlockContainerLayoutManager.java:509)
at org.apache.fop.layoutmgr.BlockContainerLayoutManager.getNextKnuthElements(BlockContainerLayoutManager.java:195)
at org.apache.fop.layoutmgr.StaticContentLayoutManager$StaticContentBreaker.getNextKnuthElements(StaticContentLayoutManager.java:317)
at org.apache.fop.layoutmgr.AbstractBreaker.getNextBlockList(AbstractBreaker.java:551)
at org.apache.fop.layoutmgr.AbstractBreaker.doLayout(AbstractBreaker.java:301)
at org.apache.fop.layoutmgr.StaticContentLayoutManager.doLayout(StaticContentLayoutManager.java:239)
at org.apache.fop.layoutmgr.PageSequenceLayoutManager.layoutSideRegion(PageSequenceLayoutManager.java:407)
at org.apache.fop.layoutmgr.PageSequenceLayoutManager.finishPage(PageSequenceLayoutManager.java:415)
at org.apache.fop.layoutmgr.PageSequenceLayoutManager.makeNewPage(PageSequenceLayoutManager.java:377)
at org.apache.fop.layoutmgr.PageBreaker.handleBreakTrait(PageBreaker.java:492)
at org.apache.fop.layoutmgr.PageBreaker.startPart(PageBreaker.java:398)
at org.apache.fop.layoutmgr.AbstractBreaker.addAreas(AbstractBreaker.java:420)
at org.apache.fop.layoutmgr.AbstractBreaker.addAreas(AbstractBreaker.java:370)
at org.apache.fop.layoutmgr.PageBreaker.doPhase3(PageBreaker.java:262)
at org.apache.fop.layoutmgr.AbstractBreaker.doLayout(AbstractBreaker.java:345)

Answer 1

OOM或OOME（OutOfMemoryError）仅仅意味着JVM内存不足。发生这种情况时，您基本上有两种选择：

• 允许JVM使用-Xmx VM参数使用更多内存。例如，要允许JVM使用1GB（1024MB）的内存：

• 改进/修复应用程序，使其使用更少的内存。 有关moer信息，请点击此链接

http://www.mkyong.com/eclipse/eclipse-java-lang-outofmemoryerror-java-heap-space/

Answer 2

使用64位Java运行时

如果您运行的是32位Java运行时，最大堆大小为1024。但使用64位，它可以达到CPU RAM的高度。对于我的情况，我需要设置为9216MB，我可以呈现多达5000页的PDF