I have a simple XML file and a simple DTD representing it.
I am working with the assumption that it is feasible, albeit maybe not suitable, to validate markup using a DTD (as opposed to an actual schema, which I believe is the most powerful and suitable option).
Based on this assumption, I figured I'd give it a try with StaX.
Problem
StaX doesn't seem to validate anything even when provided a valid DTD, and the XML file does not match the schema defined in the DTD.
I was expecting the code below to fail with some validation-related stack trace, instead of printing all the element names in my foo.xml file.
I figure there might be something very wrong with my assumptions, but I couldn't find any specific explanation in the relevant SO questions I browsed, nor in other online literature.
Code and resources below.
foo.dtd
<?xml version="1.0" encoding="UTF-8"?>
<!ELEMENT foo (bar+) >
<!ATTLIST foo
foo CDATA #REQUIRED
>
<!ELEMENT bar (#PCDATA) >
<!ATTLIST bar
bar (bar|blah) #REQUIRED
>
foo.xml
<?xml version="1.0" encoding="UTF-8"?>
<foo foo="foo">
<!-- attribute "blah" invalid -->
<bar bar="bar" blah="blah">bar</bar>
<!-- invalid -->
<bar />
</foo>
code
XMLInputFactory xif = XMLInputFactory.newFactory();
// not sure if this is required? doens't seem to help
xif.setProperty(XMLInputFactory.IS_VALIDATING, "true");
// adding dtd
xif.setXMLResolver(
new XMLResolver() {
public Object resolveEntity(String publicID, String systemID, String baseURI, String namespace) throws XMLStreamException {
if ("foo.dtd".equals(systemID)) {
return Main.class.getResourceAsStream("foo.dtd");
}
else {
return null;
}
};
}
);
XMLStreamReader reader = null;
try {
reader = xif.createXMLStreamReader(Main.class.getResourceAsStream("foo.xml"));
while (reader.hasNext()) {
switch (reader.next()) {
// prints local name just for testing
// - expecting this to fail at some point
case XMLStreamReader.START_ELEMENT:
System.out.println(reader.getLocalName());
}
}
}
finally {
if (reader != null) {
try {
reader.close();
}
catch (Exception e) {}
}
}
Output (was expecting some stack trace)
foo
bar
bar
