OutputOf_TestRdfXmlOnBlankNodes

2013-Oct-04 17:52:34.010 PDT DEBUG [main] [org.apache.jena.riot.stream.JenaIOEnvironment:createLocationMapper] [JenaIOEnvironment.java:181] [] [] [] - Failed to find configuration: location-mapping.ttl;location-mapping.rdf;location-mapping.n3;etc/location-mapping.rdf;etc/location-mapping.n3;etc/location-mapping.ttl
=== FILE CONTENTS ===
_:b0 <http://p> <http://o> . 
=== MODEL CONTENTS ===
blank URI URI
Exception in thread "main" com.hp.hpl.jena.shared.BadURIException: Only well-formed absolute URIrefs can be included in RDF/XML output: <http://> Code: 57/REQUIRED_COMPONENT_MISSING in HOST: A component that is required by the scheme is missing.
  at com.hp.hpl.jena.xmloutput.impl.BaseXMLWriter.checkURI(BaseXMLWriter.java:820)
	at com.hp.hpl.jena.xmloutput.impl.BaseXMLWriter.xmlnsDecl(BaseXMLWriter.java:339)
	at com.hp.hpl.jena.xmloutput.impl.Basic.writeRDFHeader(Basic.java:64)
	at com.hp.hpl.jena.xmloutput.impl.Basic.writeBody(Basic.java:47)
	at com.hp.hpl.jena.xmloutput.impl.BaseXMLWriter.writeXMLBody(BaseXMLWriter.java:492)
	at com.hp.hpl.jena.xmloutput.impl.BaseXMLWriter.write(BaseXMLWriter.java:464)
	at com.hp.hpl.jena.xmloutput.impl.BaseXMLWriter.write(BaseXMLWriter.java:450)
	at mypackage.TestRdfXmlOnBlankNodes.main(TestRdfXmlOnBlankNodes.java:47)

TestRdfXmlOnBlankNodes.java

package mypackage;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.rdf.model.RDFReader;
import com.hp.hpl.jena.rdf.model.RDFWriter;
import com.hp.hpl.jena.rdf.model.Resource;
import com.hp.hpl.jena.rdf.model.Statement;
import com.hp.hpl.jena.rdf.model.StmtIterator;

public class TestRdfXmlOnBlankNodes {

  public static void main(String... args) throws IOException {
		Model m = ModelFactory.createDefaultModel();
		RDFReader arp = m.getReader("N-TRIPLES");

		// File contents = "_:b0 <http://p> <http://o> ."
		URL someTriples = Thread.currentThread().getContextClassLoader()
				.getResource("mypackage/tripleWithBNodeAsSubject.nt");

		if (someTriples == null) {
			System.err.println("file not found");
			System.exit(1);
		}

		System.out.println("=== FILE CONTENTS ===");
		InputStream in = someTriples.openStream();
		System.out.println(convertStreamToString(in));

		in = someTriples.openStream();
		arp.read(m, in, null);
		in.close();

		System.out.println("=== MODEL CONTENTS ===");
		printAll(m);

		RDFWriter writer = m.getWriter("RDF/XML");
		writer.write(m, System.out, null);
	}

	private static void printAll(Model model) {
		StmtIterator iter = model.listStatements();
		try {
			while (iter.hasNext()) {
				Statement stmt = iter.next();

				Resource s = stmt.getSubject();
				Resource p = stmt.getPredicate();
				RDFNode o = stmt.getObject();

				if (s.isURIResource()) {
					System.out.print("URI");
				} else if (s.isAnon()) {
					System.out.print("blank");
				}

				if (p.isURIResource())
					System.out.print(" URI ");

				if (o.isURIResource()) {
					System.out.print("URI");
				} else if (o.isAnon()) {
					System.out.print("blank");
				} else if (o.isLiteral()) {
					System.out.print("literal");
				}

				System.out.println();
			}
		} finally {
			if (iter != null)
				iter.close();
		}
	}

	private static String convertStreamToString(java.io.InputStream is) {
		java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
		return s.hasNext() ? s.next() : "";
	}
}

The above code illustrates what I think may be a bug in Jena 2.11.0 for the RDF/XML serializer

Andy Seaborne explains the issue at:
http://mail-archives.apache.org/mod_mbox/jena-users/201310.mbox/browser