java StAX parser: not preserving double quotes for attributes

Question

StAX parser is converting the double quotes around attributes to single quotes in the data model used by XMLEventReader. This is fine, but If I want to print back the XML, perhaps selecting only a fragment of the original XML, the output will not be the same.

Input file:

<root>
  <mySubTrees>
    <mySubTree>
      <a property="target">
        <aa>123</aa>
      </a>
      <b>456</b>
      <c>789</c>
    </mySubTree>
  </mySubTrees>
</root>

Code:

@Test
public void test_getXmlFragment() throws Exception {
  byte[] fileContent = getXMLBytes();
  String xmlFragment = "";

  XMLInputFactory factory = XMLInputFactory.newInstance();
  XMLEventReader eventReader = factory.createXMLEventReader(new ByteArrayInputStream(fileContent));
  while (eventReader.hasNext()) {
    XMLEvent event = eventReader.nextEvent();
    xmlFragment += event;
  }

  System.out.println(xmlFragment);
}

private byte[] getXMLBytes() throws IOException {
  InputStream inputStream = this.getClass().getResource(PREFIX_XML_FILES + "/sss.xml").openStream();
  byte[] fileContent = new byte[inputStream.available()];
  inputStream.read(fileContent);
  inputStream.close();
  return fileContent;
}

Output:

<?xml version="null" encoding='UTF-8' standalone='no'?>
<root>
    <mySubTrees>
        <mySubTree>
            <a property='target'>
                <aa>123</aa>
            </a>
            <b>456</b>
            <c>789</c>
        </mySubTree>
    </mySubTrees>
</root>

Desired Output:

<?xml version="null" encoding="UTF-8" standalone="no"?>
<root>
    <mySubTrees>
        <mySubTree>
            <a property="target">
                <aa>123</aa>
            </a>
            <b>456</b>
            <c>789</c>
        </mySubTree>
    </mySubTrees>
</root>

Is there any way how to fine-tune this?

Answer 1

No. There is no difference between an attribute wrapped in single quotes or in double quotes, and it is an unreasonable requirement to demand a difference between the two.

StAX's job is not to preserve the XML file syntax it is reading. StAX is a parser, its job is to relay the data model expressed in the XML it is reading. And it is doing this job perfectly.

A requirement like yours is likely to force you to write your own XML library, because you shouldn't have this requirement in the first place.