Problems with using SAXParser.parse with an InputStream

Question

Hello:
I have successfully run the echo01 program from the XML tutorial. I made the following changes to parse the output from a servlet which generates an XML document.
URL recordedSensor = new URL("http://redbd01:8010/servlet/RecordedSensor?vin=1M000000000000001");
URLConnection rsConn = recordedSensor.openConnection();
// Parse the input
SAXParser saxParser = factory.newSAXParser();
saxParser.parse( rsConn.getInputStream(), handler);
I get the following errors when I try to run the code.
org.xml.sax.SAXParseException: java.lang.NullPointerException
at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:524)
at org.apache.crimson.parser.Parser2.parse(Parser2.java:305)
at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:442)
at javax.xml.parsers.SAXParser.parse(SAXParser.java:393)
at javax.xml.parsers.SAXParser.parse(SAXParser.java:191)
at ServletInterface.main(ServletInterface.java:29)
I think I have the problem narrowed down to the handlers accessing the class variable out which is a Writer the emit() method uses to output the document. When I replace out.write in emit() with System.out.println() the code works.
I've tried accessing other class variables in the handler methods with similar results.
Anybody encountered similar problems? And what is the solution.
Thanks in advance,
Gary

Answer 1

I have the same problem, if you find a solution let me know. I've double checked my objects to make sure their not null, I've checked my constructors in the extended default handler, not really sure where else to look, its such a simple program....