getting stackoverflowerror while converting org.w3c.dom.Document to org.dom4j.Document

Question

I am getting stackoverflowerror while conveting org.w3c.dom.Document to org.dom4j.Document

Code :

public static org.dom4j.Document getDom4jDocument(Document w3cDocument)
    {
        //System.out.println("XMLUtility : Inside getDom4jDocument()");
        org.dom4j.Document dom4jDocument  = null;
        DOMReader xmlReader  = null;
        try{
            //System.out.println("Before conversion of w3cdoc to dom4jdoc");
            xmlReader = new DOMReader();            
            dom4jDocument = xmlReader.read(w3cDocument);
            //System.out.println("Conversion complete");
        }catch(Exception e){
            System.out.println("General Exception :- "+e.getMessage());
        }
        //System.out.println("XMLUtility : getDom4jDocument() Finished");
        return dom4jDocument;   
    }

log :

java.lang.StackOverflowError
    at java.lang.String.indexOf(String.java:1564)
    at java.lang.String.indexOf(String.java:1546)
    at org.dom4j.tree.NamespaceStack.getQName(NamespaceStack.java:158)
    at org.dom4j.io.DOMReader.readElement(DOMReader.java:184)
    at org.dom4j.io.DOMReader.readTree(DOMReader.java:93)
    at org.dom4j.io.DOMReader.readElement(DOMReader.java:226)
    at org.dom4j.io.DOMReader.readTree(DOMReader.java:93)
    at org.dom4j.io.DOMReader.readElement(DOMReader.java:226)

Actually i want to convert XML to string by using org.dom4j.Document's asXML method. Is this conversion possible without converting org.w3c.dom.Document to org.dom4j.Document ? How ?

Can you paste the stack trace. Nothing in that code suggests a stackoverflow. @thinksteep Relevant? A document that was too large would cause a `OutOfMemoryException` not `StackOverflowException` would it not? — Jivings, Jan 19 '12 at 13:02
Is that the whole exception? Where is the method you you wrote which starts the method chain? Is it being thrown from the line `dom4jDocument = xmlReader.read(w3cDocument);`? — Jivings, Jan 19 '12 at 13:08

score 0 · Answer 1 · edited May 23 '17 at 11:58

Take a look at java.lang.StackOverflowError in dom parser. Apparently trying to load a huge XML file into a String can result in a StackoverflowException. I think it's because the parser uses regex's to find the start and end of tags, which involves recursive calls for long Strings as described in java.lang.StackOverflowError while using a RegEx to Parse big strings.

You can try and split up the XML document and parse the sections separately and see if that helps.

vaugham · Accepted Answer · 2012-01-19T13:32:23.953

when handling a heavy file, you shouldn't use a DOM reader, but a SAX one. I assume your goal is to output your document to a string.

Here you can find some differences between SAX and DOM (source) :

SAX

Parses node by node
Doesn’t store the XML in memory
We cant insert or delete a node
SAX is an event based parser
SAX is a Simple API for XML
doesn’t preserve comments
SAX generally runs a little faster than DOM

DOM

Stores the entire XML document into memory before processing
Occupies more memory
We can insert or delete nodes
Traverse in any direction.
DOM is a tree model parser
Document Object Model (DOM) API
Preserves comments
SAX generally runs a little faster than DOM

You don't need to produce a model which will need a lot of memory space. You only need to crawl through nodes to output them one by one.

Here, you will find some code to start with ; then you should implement a tree traversal algorithm.

Regards

getting stackoverflowerror while converting org.w3c.dom.Document to org.dom4j.Document

2 Answers2