How to find the line no.

Question

I am parsing an xml document and doing its custom validation (i.e putting in my own constraints).so can i notify on which line no. of the xml document is the error present?if yes how?

Answer 1

Rather than worry about a Locator, if you know the row number and column number where the problem occurs, how about using the non-locator constructors, such as:
public SAXParseException(String message,
String publicId,
String systemId,
int lineNumber,
int columnNumber)
Create a new SAXParseException.
This constructor is most useful for parser writers.
If the system identifier is a URL, the parser must resolve it fully before creating the exception.
Parameters:
message - The error or warning message.
publicId - The public identifer of the entity that generated the error or warning.
systemId - The system identifer of the entity that generated the error or warning.
lineNumber - The line number of the end of the text that caused the error or warning.
columnNumber - The column number of the end of the text that cause the error or warning.
Then you can do something like:
String msg = "complaint about the problem";
String fn = file.getPath(); /* or some string description of the file/stream you
are processing */
throw new SAXParseException( msg, fn, fn, row, col );Then, in your ErrorHandler implementation, you can use code like:
    /** Returns a string of the location. */
    private String getLocationString(SAXParseException ex) {
        StringBuffer str = new StringBuffer();
        String systemId = ex.getSystemId();
        if (systemId != null) {
            int index = systemId.lastIndexOf('/');
            if (index != -1)
                systemId = systemId.substring(index + 1);
            str.append(systemId);
        str.append(':');
        str.append(ex.getLineNumber());
        str.append(':');
        str.append(ex.getColumnNumber());
        return str.toString();
    }Dave Patterson