XOM API for Processing XML with Java

[Janek Bogucki <janekdb AT yahoo.co.uk>]

 --- Elliotte Rusty Harold <elharo AT metalab.unc.edu> wrote: > 
> It's been pointed out that nu.xom.ParseException conflicts with
> java.text.ParseException. I'd certainly prefer not to have any needless
> name conflicts between XOM and the classes in the java.* packages. Thus
> a name change is called for. Possible new names for this class include:
> 
> XMLParseException
> ParserException
> ParsingException
> 
> Please let me know which one you prefer, or any other suggestions you
> might have. Thanks! I've already implemented the NodeFactory and
> Serializer changes discussed here over the last couple of weeks, so once
> we decide on a new name for ParseException, I can push 1.0d19 out the door.
> -- 
> 
>    Elliotte Rusty Harold

Looking through the usage of ParseException leads me to believe a better name 
would be:

        WellformednessException

In the majority of uses where ParseException is caught it is assumed to be a 
well-formedness
error. ParseException is thrown in Builder and it looks like it's in response 
to a well-formedness
problem on both occassions. PsuedoAttributes also throws ParseException but 
someone familiar with
this class should comment on the intention here.

One notable exception to these pattern of usage is in SchemaValidator where 
we have:

    catch (ParseException ex) {
      System.out.println(args[0] + " is not schema valid.");
      System.out.println(ex.getMessage());
      ex.printStackTrace();
      System.out.println(" at line " + ex.getLineNumber()
        + ", column " + ex.getColumnNumber());
    }

but the method throwing ParseException should probably be throwing 
nu.xom.ValidityException
instead. Whether a validity exception remains a subclass of a wellformedness 
exception is another
question.

So in summary I suggest

   fix up uses of ParseException that should be uses of ValidityException
   replace ParseException with WellformednessException

One problem with this suggestion is that it leaves XOM without a sutiable 
generic superclass for
all checked exceptions thrown in XOM (because the name is 
WellformedException) so maybe this is an
argument for a subclass of XOMException (where XOMException is the generic 
superclass for checked
exceptions).

Having said that the generic superclass of all runtime exceptions is named 
XMLException and there
may be runtime exceptions unrelated to XML thrown. The obvious proposal here 
is:

     XOMException for checked exceptions
     XOMRuntimeException for unchecked exceptions

My two Euros.

-Janek

Below are extracts of catchs of ParseException from 1.0d18. Not included are 
usages where the
thrown ParseException is stackTraced'd to err without supplementary 
information being prefixed. So
it's not scientific...


samples/ElementLister.java-    // indicates a well-formedness error
samples/ElementLister.java:    catch (ParseException e) {

samples/CommentReader.java:        catch (ParseException ex) {
samples/CommentReader.java-          System.out.println(args[0] + " is not 
well-formed.");

samples/FibonacciXMLRPCClient.java:    catch (ParseException ex) {
samples/FibonacciXMLRPCClient.java-      System.err.println("Server sent 
malformed output");
samples/FibonacciXMLRPCClient.java-      System.err.println(ex);

samples/Linkset.java:    catch (ParseException e) {
samples/Linkset.java-      System.out.println(url + " is not well-formed.");
samples/Linkset.java-    }

samples/NodeLister.java:    catch (ParseException e) {
samples/NodeLister.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/NodeLister.java-      System.out.println(e.getMessage());
samples/NodeLister.java-    }

samples/PrettyPrinter.java:        catch (ParseException ex) {
samples/PrettyPrinter.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/PrettyPrinter.java-          System.out.println(ex.getMessage());
samples/PrettyPrinter.java-        }

samples/ProcessingInstructionLister.java:        catch (ParseException ex) {
samples/ProcessingInstructionLister.java-          System.out.println(args[0] 
+ " is not
well-formed.");
samples/ProcessingInstructionLister.java-          
System.out.println(ex.getMessage());
samples/ProcessingInstructionLister.java-        }


samples/PseudoAttributes.java:            throw new ParseException(pi.toXML()
samples/PseudoAttributes.java-             + " is not in pseudo-attribute 
format.", ex);

samples/RDDLStripper.java:        catch (ParseException ex) {
samples/RDDLStripper.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/RDDLStripper.java-          System.out.println(ex.getMessage());
samples/RDDLStripper.java-        }

samples/ResourceToTable.java:        catch (ParseException ex) {
samples/ResourceToTable.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/ResourceToTable.java-        }

samples/Restructurer.java:        catch (ParseException e) {
samples/Restructurer.java-            System.out.println(url + " is not 
well-formed.");
samples/Restructurer.java-        }

samples/SchemaValidator.java:    catch (ParseException ex) {
samples/SchemaValidator.java-      System.out.println(args[0] + " is not 
schema valid.");
samples/SchemaValidator.java-      System.out.println(ex.getMessage());
samples/SchemaValidator.java-      ex.printStackTrace();
samples/SchemaValidator.java-      System.out.println(" at line " + 
ex.getLineNumber()
samples/SchemaValidator.java-        + ", column " + ex.getColumnNumber());
samples/SchemaValidator.java-    }

samples/TextExtractor.java:        catch (ParseException ex) {
samples/TextExtractor.java-            System.out.println(args[0] + " is not 
well-formed.");
samples/TextExtractor.java-            System.out.println(" at line " + 
ex.getLineNumber()
samples/TextExtractor.java-              + ", column " + 
ex.getColumnNumber());
samples/TextExtractor.java-            System.out.println(ex.getMessage());
samples/TextExtractor.java-        }

samples/TreePrinter.java-    // indicates a well-formedness error
samples/TreePrinter.java:    catch (ParseException e) {
samples/TreePrinter.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/TreePrinter.java-      System.out.println(e.getMessage());
samples/TreePrinter.java-    }

samples/Validator.java:import nu.xom.ParseException;
samples/Validator.java-import nu.xom.ValidityException;
samples/Validator.java-
samples/Validator.java-/**
samples/Validator.java- * <p>
samples/Validator.java- *   Demonstrates validation via the 
<code>Builder</code> class.
samples/Validator.java- * </p>
samples/Validator.java- *
samples/Validator.java- * @author Elliotte Rusty Harold
samples/Validator.java- * @version 1.0d18
samples/Validator.java- *
samples/Validator.java- */
samples/Validator.java-public class Validator {
samples/Validator.java-
samples/Validator.java-  public static void main(String[] args) {
samples/Validator.java-
samples/Validator.java-    if (args.length <= 0) {
samples/Validator.java-      System.out.println("Usage: java 
nu.xom.samples.Validator URL");
samples/Validator.java-      return;
samples/Validator.java-    }
samples/Validator.java-
samples/Validator.java-    try {
samples/Validator.java-      Builder parser = new Builder(true);
samples/Validator.java-      parser.build(args[0]);
samples/Validator.java-      System.out.println(args[0] + " is valid.");
samples/Validator.java-    }
samples/Validator.java-    catch (ValidityException ex) {
samples/Validator.java-      System.out.println(args[0] + " is not valid.");
samples/Validator.java-      System.out.println(ex.getMessage());
samples/Validator.java-      System.out.println(" at line " + 
ex.getLineNumber()
samples/Validator.java-        + ", column " + ex.getColumnNumber());
samples/Validator.java-    }
samples/Validator.java:    catch (ParseException ex) {
samples/Validator.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/Validator.java-      System.out.println(ex.getMessage());
samples/Validator.java-      System.out.println(" at line " + 
ex.getLineNumber()
samples/Validator.java-        + ", column " + ex.getColumnNumber());
samples/Validator.java-    }

samples/XHTMLPurifier.java:        catch (ParseException ex) {
samples/XHTMLPurifier.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/XHTMLPurifier.java-          System.out.println(ex.getMessage());
samples/XHTMLPurifier.java-        }

amples/XHTMLQualifier.java:    catch (ParseException e) {
samples/XHTMLQualifier.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/XHTMLQualifier.java-      System.out.println(e.getMessage());
samples/XHTMLQualifier.java-    }

samples/XHTMLValidator.java:      catch (ParseException e) {
samples/XHTMLValidator.java-        System.out.println(source
samples/XHTMLValidator.java-         + " is invalid XML, and thus not 
XHTML.");
samples/XHTMLValidator.java-        return;
samples/XHTMLValidator.java-      }

samples/XMLPrinter.java:        catch (ParseException ex) {
samples/XMLPrinter.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/XMLPrinter.java-          System.out.println(ex.getMessage());
samples/XMLPrinter.java-        }

samples/XOMChecker.java:    catch (ParseException ex) {
samples/XOMChecker.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/XOMChecker.java-      System.out.println(ex.getMessage());
samples/XOMChecker.java-      System.out.println(" at line " + 
ex.getLineNumber()
samples/XOMChecker.java-        + ", column " + ex.getColumnNumber());
samples/XOMChecker.java-    }

samples/StreamingCommentReader.java:        catch (ParseException ex) {
samples/StreamingCommentReader.java-          System.out.println(args[0] + " 
is not
well-formed.");
samples/StreamingCommentReader.java-          
System.out.println(ex.getMessage());
samples/StreamingCommentReader.java-        }

samples/StreamingElementLister.java:        catch (ParseException e) {
samples/StreamingElementLister.java-            System.out.println(args[0] + 
" is not
well-formed.");
samples/StreamingElementLister.java-            
System.out.println(e.getMessage());
samples/StreamingElementLister.java-        }

samples/RDDLToTable.java:        catch (ParseException ex) {
samples/RDDLToTable.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/RDDLToTable.java-          System.out.println(ex.getMessage());
samples/RDDLToTable.java-        }


samples/StreamingNodeLister.java-    // indicates a well-formedness error
samples/StreamingNodeLister.java:    catch (ParseException ex) {
samples/StreamingNodeLister.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/StreamingNodeLister.java-      System.out.println(ex.getMessage());
samples/StreamingNodeLister.java-    }

samples/StreamingProcessingInstructionLister.java:        catch 
(ParseException ex) {
samples/StreamingProcessingInstructionLister.java-          
System.out.println(args[0] + " is not
well-formed.");
samples/StreamingProcessingInstructionLister.java-          
System.out.println(ex.getMessage());
samples/StreamingProcessingInstructionLister.java-        }

samples/StreamingPropertyPrinter.java:        catch (ParseException ex) {
samples/StreamingPropertyPrinter.java-          System.out.println(args[0] + 
" is not
well-formed.");
samples/StreamingPropertyPrinter.java-          
System.out.println(ex.getMessage());
samples/StreamingPropertyPrinter.java-        }

samples/StreamingTextExtractor.java:        catch (ParseException ex) {
samples/StreamingTextExtractor.java-          System.out.println(args[0] + " 
is not
well-formed.");
samples/StreamingTextExtractor.java-          
System.out.println(ex.getMessage());
samples/StreamingTextExtractor.java-        }

samples/StreamingTreeReporter.java:        catch (ParseException ex) {
samples/StreamingTreeReporter.java-          System.out.println(args[0] + " 
is not well-formed.");
samples/StreamingTreeReporter.java-          
System.out.println(ex.getMessage());
samples/StreamingTreeReporter.java-        }

samples/StreamingXHTMLQualifier.java:        catch (ParseException ex) {
samples/StreamingXHTMLQualifier.java-          System.out.println(args[0] + " 
is not
well-formed.");
samples/StreamingXHTMLQualifier.java-          
System.out.println(ex.getMessage());
samples/StreamingXHTMLQualifier.java-        }

samples/PureValidator.java:    catch (ParseException ex) {
samples/PureValidator.java-      System.out.println(args[0] + " is not 
well-formed.");
samples/PureValidator.java-      System.out.println(ex.getMessage());
samples/PureValidator.java-      System.out.println(" at line " + 
ex.getLineNumber()
samples/PureValidator.java-        + ", column " + ex.getColumnNumber());
samples/PureValidator.java-    }

samples/RSSHeadlines.java:        catch (ParseException ex) {
samples/RSSHeadlines.java-          System.out.println(url + " is not 
well-formed.");
samples/RSSHeadlines.java-          System.out.println(ex.getMessage());
samples/RSSHeadlines.java-        }

samples/RDDLFilter.java:        catch (ParseException ex) {
samples/RDDLFilter.java-          System.out.println(args[0] + " is not 
well-formed.");
samples/RDDLFilter.java-          System.out.println(ex.getMessage());
samples/RDDLFilter.java-        }




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