Async parse of simple document fails with WFCException: Unexpected character 'd' (code 100) in epilog

This is a test case with the simplest document I could find. The code reproducing the problem is a copy-paste of an official example with a small fix.

  @Test
  public void asynchronousParseSmallestDocument() throws Exception {
    final String xml = 
//        "<?xml version=\"1.0\" encoding=\"US-ASCII\"?>" +
        "<d/>" ;

    final AsyncXMLInputFactory asyncXmlInputFactory = new InputFactoryImpl() ;
    final AsyncXMLStreamReader< AsyncByteArrayFeeder > xmlStreamReader =
        asyncXmlInputFactory.createAsyncFor( xml.getBytes( Charsets.US_ASCII ) ) ;
    final AsyncByteArrayFeeder inputFeeder = xmlStreamReader.getInputFeeder() ;

    byte[] xmlBytes = xml.getBytes() ;
    int bufferFeedLength = 1 ; 
    int currentByteOffset = 0 ;
    int type ;
    do{
      while( ( type = xmlStreamReader.next() ) == AsyncXMLStreamReader.EVENT_INCOMPLETE ) {
        byte[] buffer = new byte[]{ xmlBytes[ currentByteOffset ] } ;
        currentByteOffset ++ ;
        inputFeeder.feedInput( buffer, 0, bufferFeedLength ) ;
        if( currentByteOffset >= xmlBytes.length ) {
          inputFeeder.endOfInput() ;
        }
      }
      switch( type ) {
        case XMLEvent.START_DOCUMENT :
          LOGGER.debug( "start document" ) ;
          break ;
        case XMLEvent.START_ELEMENT :
          LOGGER.debug( "start element: " + xmlStreamReader.getName() ) ;
          break ;
        case XMLEvent.CHARACTERS :
          LOGGER.debug( "characters: " + xmlStreamReader.getText() ) ;
          break ;
        case XMLEvent.END_ELEMENT :
          LOGGER.debug( "end element: " + xmlStreamReader.getName() ) ;
          break ;
        case XMLEvent.END_DOCUMENT :
          LOGGER.debug( "end document" ) ;
          break ;
        default :
          break ;
      }
    } while( type != XMLEvent.END_DOCUMENT ) ;

    xmlStreamReader.close() ;
  }

This is what I get:

15:23:41.388 DEBUG [main] c.o.s.m.c.x.SingleContactXmlParserTest - start document
15:23:41.394 DEBUG [main] c.o.s.m.c.x.SingleContactXmlParserTest - start element: d
15:23:41.394 DEBUG [main] c.o.s.m.c.x.SingleContactXmlParserTest - end element: d

com.fasterxml.aalto.WFCException: Unexpected character 'd' (code 100) in epilog (unbalanced start/end tags?)
 at [row,col {unknown-source}]: [1,7]

	at com.fasterxml.aalto.in.XmlScanner.reportInputProblem(XmlScanner.java:1333)
	at com.fasterxml.aalto.in.XmlScanner.throwUnexpectedChar(XmlScanner.java:1498)
	at com.fasterxml.aalto.in.XmlScanner.reportPrologUnexpChar(XmlScanner.java:1358)
	at com.fasterxml.aalto.async.AsyncByteArrayScanner.nextFromProlog(AsyncByteArrayScanner.java:1068)
	at com.fasterxml.aalto.stax.StreamReaderImpl.next(StreamReaderImpl.java:802)
	at com.otcdlink.server.model.contact.xml.SingleContactXmlParserTest.asynchronousParseSmallestDocument(SingleContactXmlParserTest.java:102)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

I’m using aalto-xml 1.0.

[cowtowncoder]

@aamalik Thank you for sharing! And yes, I understand no one asks questions to annoy. Nor should it, it’s just that across many repos it sometimes feels questions are asked without reading the full thread. And it is difficult to also know how difficult they are to follow. So frustration I had was more general; apologies for directing it to you and others here.

But the important thing is that there is more information now, and error handling in 1.1.0 is better to also help recognizing the issue. Thank you everyone in helping us get there.

[asfandyar-malik]

Standalone Runnable Java Code incase somebody wants async xml file reading.

import com.fasterxml.aalto.AsyncByteArrayFeeder;
import com.fasterxml.aalto.AsyncXMLInputFactory;
import com.fasterxml.aalto.AsyncXMLStreamReader;
import com.fasterxml.aalto.stax.InputFactoryImpl;

import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.XMLEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;

public class AkkaGpxTest {

    public ArrayList<LatLon> extractLatLonFromFile() throws XMLStreamException, IOException {

        final AsyncXMLInputFactory f = new InputFactoryImpl();
        AsyncXMLStreamReader<AsyncByteArrayFeeder> sc = null;

        ClassLoader classLoader = getClass().getClassLoader();
        File file = new File(classLoader.getResource("AnyXMLFile.xml").getFile());

        //init array with file length
        byte[] xmlBytes = new byte[(int) file.length()];

        FileInputStream fis = new FileInputStream(file);
        fis.read(xmlBytes); //read file into bytes[]
        fis.close();

        sc = f.createAsyncForByteArray();

        ArrayList<LatLon> latlonList = new ArrayList<LatLon>();

        int bufferFeedLength = 1 ;
        int currentByteOffset = 0 ;
        int type ;
        do{
            while( (type = sc.next()) == AsyncXMLStreamReader.EVENT_INCOMPLETE ) {
                byte[] buffer = new byte[]{ xmlBytes[ currentByteOffset ] } ;
                currentByteOffset ++ ;
                sc.getInputFeeder().feedInput( buffer, 0, bufferFeedLength ) ;
                if( currentByteOffset >= xmlBytes.length ) {
                    sc.getInputFeeder().endOfInput() ;
                }
            }
            switch( type ) {

                case XMLEvent.START_DOCUMENT :
                    System.out.println( "start document" ) ;
                    break ;

                case XMLEvent.START_ELEMENT :
                    System.out.println( "start element: " + sc.getName());
                    break ;

                case XMLEvent.CHARACTERS :
                    System.out.println( "characters: " + sc.getText()) ;
                    break ;

                case XMLEvent.END_ELEMENT :
                    System.out.println( "end element: " + sc.getName()) ;
                    break ;

                case XMLEvent.END_DOCUMENT :
                    System.out.println( "end document" ) ;
                    break ;

                default :
                    break ;
            }
        } while( type != XMLEvent.END_DOCUMENT ) ;
        sc.close();

    }

    public static void main(String[] args) throws IOException, XMLStreamException {

        AkkaGpxTest jt = new AkkaGpxTest();
        jt.extractLatLonFromFile();
    }
}