StackOverflow when serializing a XML Document Object to Byte Array.<br>

workaround: None available. We even tried -oss option with all permissible stack sizes, but
in vain.

minusVersion: java version "1.1.8"

description: java version "1.1.8"

We are running a CORBA server which parses some xml files, generates a XML
Document object out of them and serializes it to a byte[], one at a
time.(Operations are single threaded)
The XML files are a bit deeply nested and contain around 1000 lines. These files
are configuration files for other servers. So, when a new Server is added thru
the GUI (which is Swing/JSP and browser based), the server copies a template
file( Which is about 50 lines of XML) to a new file, parses the new file , gets
the XML document object out of it, and tries to serialize it to a byte[]. This
is where StackOverflow exception is thrown and it is thrown from writeObject()
method. If the server is restarted, it successfully parses all the existing
file (any number) and all corresponding documents as successfully serialized.
But again if a new request to add server comes, StackOverFlow is encountered. We
are using IBM XML Parser(org.w3c.dom.*). We can't move to JDK1.2 because of
compatibility reasons with VisiBroker(The ORB which we are using). We tried all
alternatives, code reviews at our best level but the problem remains. As this
has hampered the whole product release any quick help will be appreciated. I am
attaching the relevant code :

***********************************************
CODE that produces the above mentioned bug
***********************************************
[&lt;javacode&gt;]
public byte[] getComponentConfiguration(String type, String instanceId) throws DocNotFoundException, DocFormatException
{
String objectId=type+"."+instanceId;
String filePath=null;
byte[] serializedDoc=null;

trace("In getComponentConfiguration");
try
{
return getFromCache(objectId);
}
catch(DocNotFoundException e)
{
trace("Doc Not found exception thrown for "+objectId);
// The doc was not in cache. Could have been added later by the
admin.
}
// what if it was added later ?? Need to get file path from CIC and try
once

try
{
trace("Attempting another try to get the doc for "+objectId);

filePath=cicReference.getServerProperty(type,instanceId,XML_FILE_PATH);
trace("Got the filepath : "+filePath);
}
catch(InvalidTypeException e)
{
throw new DocNotFoundException("The server "+objectId+" doesnt
exist.");
} catch(InvalidInstanceException e)
{
throw new DocNotFoundException("The server "+objectId+" doesnt
exist.");
}
//************Relevant CODE Starts here********
try
{
trace("^^^^^^^^^^^^^^^^^^^^^^^ File Path :"+filePath);
//Parse the file and get org.w3c.dom.Document object..
Document docu = XMLConfigUtils.getDocument(filePath);
System.out.println(XMLConfigUtils.getGlobalConfigHashtable(docu));
//Stackoverflow occurs in This method. Code for //this method is given below

serializedDoc=XMLConfigUtils.getSerializedDocument(filePath);
trace("Serialized the doc");
cacheSerializedDoc(objectId,serializedDoc,false,filePath);
trace("cached the doc");
return serializedDoc;
}
catch( XMLFileNotFoundException e)
{
throw new DocNotFoundException("The Config file for this server was
not found");
}
catch(XMLFormatException e)
{
throw new DocFormatException("XML format of the config doc is
erroneous");
}
catch(UnableToSyncByteArrayException e)
{
throw new DocNotFoundException(e.message);
}


}
//***************************************************************************
// Code for XMLConfigUtils.getSerializedDocument(filePath).....

public static byte [] getSerializedDocument(String filename) throws
XMLFileNotFoundException, XMLFormatException
{
if(filename == null || filename.equals(""))
{
System.out.println("file name passed is null");
throw new XMLFileNotFoundException("file name passed is null");
}
Document doc= getDocument(filename);
System.out.println("Got the doc "+doc);
/***Failure occurs at this step. The same code //works without problem when server is restarting. //(While restarting, //server parses all
//available XML files including this new one and //byte[]'s of all of them are successfully //prepared. Failure occurs with same code if //new server is added at runtime.

byte [] ret = serializeDocument(doc);
System.out.println("Byte arra = "+ret);
if(ret == null)
throw new XMLFormatException(" failed");

return ret;

}
//*****Code for serializeDocument(doc)........
public static byte [] serializeDocument(Document xmlDoc)
{
try{
ByteArrayOutputStream bArray = new ByteArrayOutputStream();
ObjectOutputStream oStream = new ObjectOutputStream(bArray);
oStream.writeObject(xmlDoc);
oStream.close();
System.out.println("Before close in serializedDocument");
return bArray.toByteArray();
}catch(Throwable e)
{
e.printStackTrace();
return null;
}

}
[&lt;/javacode&gt;]

OSversion: sol2.5.1

user_type: E

subcategory: runtime

synopsis: StackOverflow when serializing a XML Document Object to Byte Array.

severity: 1

hardware: sun4

user_role: D

comments: (company - Wipro Technologies , email - [email protected])


dateCreated: May 3, 2000 3:40:44 AM

jdcid: pugsy

category: java

type: bug

release: 1.1.8

Hi ParagW,

I have been facing the same problem with yours.

Did you solve it? Would you mind to tell me your solution?

Thanks in any soon advance.

SB

Few questions :

1. What parser are you using (seems like DOM but not very clear from given code) . If you are using DOM parser and dont have much control over XML file size then sooner or later you are going to hit memory related errors , by the way 50 lines isnt too big to cause such errors. Suggestion try SAX parser.
2. How is the bytearray returnd thru your static method used (do you ever return that object to gc , meaning ever remove all references to it ?) If you keep references to all such byte arrays for use then you are ending up using all available heap and thats gonna cause an exception soon.

We have been parsing much bigger XML's but used SAX parser for the same.