CODEWITHSUNDEEP
validationjaxbsaxparserwell-formed
yzandrew
yzandrew

Reputation: 785

how to do validation with not well form XML while doing unmarshalling?

I have an unmarshaller along with an MySchema.xsd file.

    StreamSource sources = new StreamSource(getClass().getClassLoader().getResourceAsStream("/xmlValidation.xsd"));
    SchemaFactory sf = SchemaFactory.newInstance( XMLConstants.W3C_XML_SCHEMA_NS_URI );
    unmarshaller.setSchema(sf.newSchema(sources));

And make a call to unmarshaller.setEventHandler() function, to specify a custom validation event handler, which basically format a error tips string , by:

    final String errorString = new String();
    unmarshaller.setEventHandler(new ValidationEventHandler() {
        @Override
        public boolean handleEvent(ValidationEvent validationevent) {
            if(validationevent.getSeverity()!= ValidationEvent.WARNING){
                errorString.format( "Line:Col[" + validationevent.getLocator().getLineNumber()
                                    + ":" + validationevent.getLocator().getColumnNumber()
                                    + "]:" + validationevent.getMessage());
                return false;
            }
            return true;
        }
    });

The above codes seem work ok(I can get java object when the input string is validated. and also the error tips string is formated as excepted)

The problem is that, when the input xml is not well form, it also throw a SaxParseException.

Thanks in advance. Andrew

Upvotes: 1

Views: 3279

Answers (2)

bdoughan
bdoughan

Reputation: 148987

Well formed relates to the XML syntax itself, as opposed to being valid WRT an XML schema:

If you have XML that is not well formed then you will get a ValidationEvent.FATAL_ERROR and unmarshalling will not be able to continue, as the underlying parser used by JAXB cannot continue.

For more information:

Upvotes: 1

yzandrew
yzandrew

Reputation: 785

K, I mess up something and get this problem. Now I figure it out. If I am wrong, please point me out. below it's what I find in javadoc and test on my project:

javax.xml.bind.ValidationEventHandler can handler the constrain error with the given schema constrains, when unmarshaller is unmarshaling. 

unmarshaller.unmarshal(xmlInputStream);

The ValidationEventHandler will be called during the unmarshaling process if error occurs. The SAXEception will be thrown, if the xmlInputStream is not well form. And I cant find a way to catch the SAXException, throw by the sax parser, so I guess using validation during unmarshaling can't due with un-well form xml string.

I use javax.xml.validation.Validator to validate that the xml string is well form and under constrain. 

jaxbValidator.validate(xmlSource);

The above code will throw SAXException. If no exception is thrown, then unmarshall the xml string into object.

Upvotes: 0

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