Does anyone know how I can get Axis2 to use a non-coalescing XMLStreamReader when it parses a SOAP message?

I am writing code that reads a large base64 binary text element. Coalescing is the default behaviour, and this causes the default XMLStreamReader to load the entire text into memory rather than returning multiple CHARACTERS events. The upshot of this is that I run out of heap space when running the following code:

reader = element.getTextAsStream( true );

The OutOfMemory error occurs in com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next:

java.lang.OutOfMemoryError: Java heap space
    at com.sun.org.apache.xerces.internal.util.XMLStringBuffer.append(XMLStringBuffer.java:208)
    at com.sun.org.apache.xerces.internal.util.XMLStringBuffer.append(XMLStringBuffer.java:226)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanContent(XMLDocumentFragmentScannerImpl.java:1552)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2864)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:116)
    at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:558)
    at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.next(XMLStreamReaderWrapper.java:225)
    at org.apache.axiom.util.stax.dialect.DisallowDoctypeDeclStreamReaderWrapper.next(DisallowDoctypeDeclStreamReaderWrapper.java:34)
    at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.next(XMLStreamReaderWrapper.java:225)
    at org.apache.axiom.util.stax.dialect.SJSXPStreamReaderWrapper.next(SJSXPStreamReaderWrapper.java:138)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.parserNext(StAXOMBuilder.java:668)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:214)
    at org.apache.axiom.om.impl.llom.SwitchingWrapper.updateNextNode(SwitchingWrapper.java:1098)
    at org.apache.axiom.om.impl.llom.SwitchingWrapper.<init>(SwitchingWrapper.java:198)
    at org.apache.axiom.om.impl.llom.OMStAXWrapper.<init>(OMStAXWrapper.java:73)
    at org.apache.axiom.om.impl.llom.OMContainerHelper.getXMLStreamReader(OMContainerHelper.java:67)
    at org.apache.axiom.om.impl.llom.OMContainerHelper.getXMLStreamReader(OMContainerHelper.java:40)
    at org.apache.axiom.om.impl.llom.OMElementImpl.getXMLStreamReader(OMElementImpl.java:790)
    at org.apache.axiom.om.impl.llom.OMElementImplUtil.getTextAsStream(OMElementImplUtil.java:114)
    at org.apache.axiom.om.impl.llom.OMElementImpl.getTextAsStream(OMElementImpl.java:826)
    at org.example.UploadFileParser.invokeBusinessLogic(UploadFileParser.java:160)