Custom entity resolver for XMLStreamReader not working

问题

I have an xml to parse with XMLStreamReader, but it has some html entities (not part of xml standard) like accented characters that make the next() method to throw XMLStreamException: The entity "uacute" was referenced, but not declared.

I try to add a custom entity resolver implementing XMLResolver (https://docs.oracle.com/javase/8/docs/api/javax/xml/stream/XMLResolver.html), which documentation states that:

If an application wishes to perform custom entity resolution it must register an instance of this interface with the XMLInputFactory using the setXMLResolver method.

Ok, so I made this class to reproduce the error:

private void testXMLResolver() throws XMLStreamException {
    String xml = "<example>You know &oacute; is an accented character</example>";
    XMLInputFactory inputFactory = XMLInputFactory.newInstance(); // instantiate XMLInputFactory
    inputFactory.setXMLResolver(new MyEntityResolver()); // Append custom entity resolver
    XMLStreamReader xmlStreamReader = inputFactory.createXMLStreamReader(new ByteArrayInputStream(xml.getBytes())); // create XMLStreamReader for the xml
    xmlStreamReader.next(); // reads <example>
    xmlStreamReader.next(); // reads the text inside <example> tag
    System.out.println("Text is: " + xmlStreamReader.getText());
    xmlStreamReader.next();
}

class MyEntityResolver implements XMLResolver {
    @Override
    public Object resolveEntity(String publicID, String systemID, String baseURI, String namespace) throws XMLStreamException {
        return new ByteArrayInputStream("huehey!!".getBytes());
    }
}

}

Executing testXMLResolver() outputs first:

Text is: You know

And then, when the last next() is executed it throws the exception

Exception in thread "main" javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,27]
Message: The entity "oacute" was referenced, but not declared.
    at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:601)
    at Test.testXMLResolver(Test.java:21)
    at Test.main(Test.java:10)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

First: I don't know why MyXMLResolver is not resolving the entity

Second: Why does the exception is thorwn in the last next() and not the previous one? because the text is parsed in the previous one.

PS: I make the resolveEntity(...) to return an InputStream because the documentation of the method says that:

Retrieves a resource. This resource can be of the following three return types: (1) java.io.InputStream (2) javax.xml.stream.XMLStreamReader (3) java.xml.stream.XMLEventReader

回答1:

Isn't it because you have not declared ó ("uacute") ? something like this maybe:

<!DOCTYPE definition [<!ENTITY oacute "&#243;">]>

来源：https://stackoverflow.com/questions/44971191/custom-entity-resolver-for-xmlstreamreader-not-working

标签

java

xml

xml-parsing