我正在使用標準javax.xml包來解析Linux機器上的某些XML文件。我的代碼如下:使用javax.xml的Java中的錯誤文件描述符IOException
try
{
// Prepare parser
DocumentBuilder documentBuilder = documentBuilderFactory
.newDocumentBuilder();
Document document = documentBuilder.parse(file.getAbsolutePath()); // This is line 397
XPath xPath = xPathFactory.newXPath();
...
}
catch(IOException e) { ... }
單個的DocumentBuilderFactory由多個線程訪問,如同一個單一的XPathFactory,相信這是可以接受的用法。使用上述代碼解析XML文件時,偶爾會看到以下錯誤。
java.io.IOException: Bad file descriptor
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:229)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:229)
at java.io.BufferedInputStream.read(BufferedInputStream.java:246)
at org.apache.xerces.impl.XMLEntityManager$RewindableInputStream.read(Unknown Source)
at org.apache.xerces.impl.XMLEntityManager.setupCurrentEntity(Unknown Source)
at org.apache.xerces.impl.XMLVersionDetector.determineDocVersion(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
at mypackage.MyXmlParser.parseFile(MyXmlParser.java:397)
at mypackage.MyXmlParser.access$500(MyXmlParser.java:51)
at mypackage.MyXmlParser$1.call(MyXmlParser.java:337)
at mypackage.MyXmlParser$1.call(MyXmlParser.java:328)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:284)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:665)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:690)
at java.lang.Thread.run(Thread.java:799)
我偶爾(〜的時間的10%)見下面的附加文本:
Caused by:
java.io.IOException: Bad file descriptor
at org.apache.xml.serializer.ToStream.flushWriter(ToStream.java:260)
at org.apache.xml.serializer.ToXMLStream.endDocument(ToXMLStream.java:191)
at org.apache.xalan.transformer.TransformerIdentityImpl.endDocument(TransformerIdentityImpl.java:983)
at org.apache.xml.serializer.TreeWalker.traverse(TreeWalker.java:174)
at org.apache.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:410)
... 9 more
當我手動檢查文件,我可以看到,失敗的文件和所述文件之間沒有差別通過。我可以確認通過的文件是有效的XML,沒有特殊字符或提前結束。
有誰知道爲什麼會發生這種情況,以及我如何避免它?
> java -version
java version "1.5.0"
Java(TM) 2 Runtime Environment, Standard Edition (build pxa64dev-20061002a (SR3))
IBM J9 VM (build 2.3, J2RE 1.5.0 IBM J9 2.3 Linux amd64-64 j9vmxa6423-20061001 (JIT enabled)
J9VM - 20060915_08260_LHdSMr
JIT - 20060908_1811_r8
GC - 20060906_AA)
JCL - 20061002
看來你的FileStream在數據讀取開始之前被關閉。您可能需要調查爲什麼它被關閉。 – kosa 2012-04-23 18:44:34
謝謝,如果是這種情況,雖然我找不到任何理由。我沒有觸及上面發佈的javax.xml代碼之外的文件。 – Ina 2012-04-24 14:08:57