/*
* @(#)$Id: ErrorReporter.java 1598 2003-09-04 20:45:05Z kohsuke $
*
* Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
*
* This software is the proprietary information of Sun Microsystems, Inc.
* Use is subject to license terms.
*
*/
package errorinfo;
import java.io.File;
import java.io.FileInputStream;
import javax.xml.parsers.SAXParserFactory;
import com.sun.msv.verifier.ErrorInfo;
import com.sun.msv.verifier.ValidityViolation;
import org.iso_relax.verifier.*;
import org.xml.sax.*;
import org.xml.sax.helpers.XMLFilterImpl;
/**
* Uses {@link ErrorInfo} information to get detailed information about errors
* and its source.
*
* <p>
* This example takes a schema and a document, then dumps the document.
* When an error is found, the error is highlighted.
*
* <p>
* The purpose of this example is to illustrate how you can access
* {@link ErrorInfo}, which will give you detailed information of
* the error.
*
* <p>
* {@link ValidityViolation} is derived from SAXParseException, so you can
* always access line/column number information at least.
* However, since this information is about the textual representation of
* XML, it is sometimes not much useful.
*
* <p>
* <code>ErrorInfo</code> provides high-level error information,
* and therefore it is often useful to provide an
* application-specific error messages to the user.
*
* @author <a href="mailto:kohsuke.kawaguchi@sun.com">Kohsuke KAWAGUCHI</a>
*/
public class ErrorReporter
{
public static void main( String args[] ) throws Exception {
if( args.length!=2 ) {
System.out.println("ErrorReporter <schema schema> <instance file>");
return;
};
// control MSV through JARV.
// For more information about JARV, see the jarv examples.
VerifierFactory factory = new com.sun.msv.verifier.jarv.TheFactoryImpl();
// compile a schema and gets a verifier.
final Verifier verifier = factory.newVerifier(new File(args[0]));
// create a SAX parser
SAXParserFactory parserFactory = SAXParserFactory.newInstance();
parserFactory.setNamespaceAware(true);
XMLReader reader = parserFactory.newSAXParser().getXMLReader();
// then setup the SAX pipe line as follows:
//
// parser ==> interceptor ==> verifier
//
// "interceptor" works as a SAX filter.
Interceptor interceptor = new Interceptor();
interceptor.setParent(reader);
interceptor.setContentHandler(verifier.getVerifierHandler());
// set an error handler that throws any error.
verifier.setErrorHandler(
com.sun.msv.verifier.util.ErrorHandlerImpl.theInstance);
// parse the file.
interceptor.parse( new InputSource( new FileInputStream(args[1]) ) );
}
/**
* Interceptor works in this way:
*
* <ul><li>
* First, it receives a SAX event from the parser.
*
* <li>
* It then passes a SAX event to the verifier, to see if it's correct.
*
* <ul><li>
* If there is no error, then the verifier will return without
* reporting any error. So the interceptor will print it.
*
* <li>
* If there is an error, the verfieier will report an error to ErrorHandler.
* The error handler we set throws it, so Interceptor will catch it.
* If the error is catched, the interceptor will print it accordingly.
*
*/
private static class Interceptor extends XMLFilterImpl {
/**
* characters has to be buffered because of the way MSV works.
* For more information, see the javadoc of
* {@link ErrorInfo.BadText}.
*/
private StringBuffer buffer = new StringBuffer();
public void startElement(
String ns, String local, String qname, Attributes atts )
throws SAXException {
ErrorInfo ei = null;
boolean unknownError = false;
try {
super.startElement(ns,local,qname,atts);
// there is no error.
} catch( ValidityViolation vv ) {
// there was an error.
ei = vv.getErrorInfo();
if(!(ei instanceof ErrorInfo.BadText)
&& !(ei instanceof ErrorInfo.BadTagName)
&& !(ei instanceof ErrorInfo.BadAttribute)
&& !(ei instanceof ErrorInfo.MissingAttribute) )
// if the type of information is unknown to us,
// or ei equals to null
unknownError = true;
}
// print the text
printText( ei instanceof ErrorInfo.BadText );
printIndent();
print("<");
print( qname,
unknownError || // if the error is unknown, highlight the tag name
(ei instanceof ErrorInfo.BadTagName) );
for( int i=0; i<atts.getLength(); i++ ) {
boolean fError = false;
if(ei instanceof ErrorInfo.BadAttribute)
fError = ((ErrorInfo.BadAttribute)ei).
attQName.equals(atts.getQName(i));
print(" ");
print(atts.getQName(i)+"='"+atts.getValue(i)+"'", fError );
}
if( ei instanceof ErrorInfo.MissingAttribute ) {
print(" ");
print("[missing attributes]",true);
}
print(">\n");
indent++;
}
public void endElement( String ns, String local, String qname ) throws SAXException {
ErrorInfo ei = null;
try {
super.endElement(ns,local,qname);
// there is no error.
} catch( ValidityViolation vv ) {
// there was an error.
ei = vv.getErrorInfo();
}
// print the text
printText(ei instanceof ErrorInfo.BadText);
indent--;
printIndent();
print("</");
print( qname, ei instanceof ErrorInfo.IncompleteContentModel);
print(">\n");
}
public void characters( char[] buf, int start, int len ) throws SAXException {
super.characters(buf,start,len);
// just collect characters in this callback
buffer.append(buf,start,len);
}
private void printText( boolean fError ) {
String str = buffer.toString().trim();
if(str.length()!=0 || fError) {
printIndent();
print(str, fError );
print("\n");
}
// update the text buffer
buffer = new StringBuffer();
}
//
// pretty print engine
//
/** indent depth. */
private int indent = 0;
/** Prints whitespaces. */
private void printIndent() {
for( int i=0; i<indent; i++ )
System.out.print(" ");
}
/** Prints the specified string (possibly with highlighting.) */
private void print( String str, boolean highlight ) {
if(!highlight) {
System.out.print(str);
} else {
System.out.print("***");
System.out.print(str);
System.out.print("***");
}
}
private void print( String str ) {
print(str,false);
}
}
}