package com.windofkeltia.sax;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.helpers.DefaultHandler;

public class SampleHandler extends DefaultHandler
{
  private Locator  locator;
  private Position position = new Position(); // starting element position we maintain

  /** The SAX parser will call this to update locator as needed. */
  public void setDocumentLocator( Locator location ) { locator = location; }

  /** (See Javadoc above.) */
  public void startElement( String uri, String localName, String qName, Attributes attributes )
  {
    // do startElement() work here...
  }

  /** (See Javadoc above.) */
  public void endElement( String uri, String localName, String qName )
  {
    // We could get our source position--at the end
    Position start = position;
    Position end   = new Position( locator.getLineNumber(), locator.getColumnNumber() );

    // do endElement() work here

    // update the starting point for the next element
    updateElementPoint( locator );
  }

  /** (See Javadoc above.) */
  public void characters( char[] ch, int start, int length )
  {
    updateElementPoint( locator );  // now update the starting point
  }

  /** (See Javadoc above.) */
  public void ignorableWhitespace( char[] ch, int start, int length )
  {
    updateElementPoint( locator ); // now update the starting point
  }

  private void updateElementPoint( Locator locator )
  {
    Position location = new Position( locator.getLineNumber(), locator.getColumnNumber() );
    if( position.compareTo( location ) < 0 )
      position = location;
  }

  /** Wrap and maintain the SAX locator to make it more accurate. */
  static class Position
  {
    private int line;
    private int column;

    public Position()                       { this.line   = 1;    this.column = 1; }
    public Position( int line, int column ) { this.line   = line; this.column = column; }
    public void setLine( int line )         { this.line   = line; }
    public void setColumn( int column )     { this.column = column; }

    public int getLine()                    { return line; }
    public int getColumn()                  { return column; }

    public int compareTo( Position position )
    {
      // if our location is past recorded line...
      if( position.getLine() > getLine() )
        return -1;
      // if on recorded line, but past recorded column...
      else if( position.getLine() == getLine() && position.getColumn() > getColumn() )
        return -1;
      // if on recorded line and also at recorded column...
      else if( position.getLine() == getLine() && position.getColumn() == getColumn() )
        return 0;
      // we're before current line and/or current column...
      else
        return 1;
    }
  }

  private final ParserHandlerPrinter printer = new ParserHandlerPrinter( printerVerbosity );

  private static int printerVerbosity = 0;

  /** Use this from JUnit tests to set the level of debug verbosity. If not done, printer will be quiet. */
  public static void setPrinterVerbosity( int verbosity ) { printerVerbosity = verbosity; }
}

package com.windofkeltia.sax;

import java.util.HashMap;
import java.util.Map;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;

import com.windofkeltia.utilities.StringUtilities;

/**
 * Conceived as JUnit-only. Use static setPrinterVerbosity()
 * in whatever SAX parser handler consumes this to set the level
 * before instantiating the parser.
 */
public class ParserHandlerPrinter
{
  private final int verbosity;

  /** Quiet version of this utility--utters nothing. */
  public ParserHandlerPrinter() { verbosity = 0; }

  /**
   * Enable this utility at any of several levels:
   *
   * 0 - none (quiet mode)
   * 1 - minimal output
   * 2 - verbose output without line numbers
   * 3 - verbose output including line numbers
   */
  public ParserHandlerPrinter( int verbosity ) { this.verbosity = verbosity; }

  public void startElement( Locator locator, final String elementName, Attributes attributes )
  {
    StringBuilder sb = new StringBuilder();
    switch( verbosity )
    {
      case 3 :
        sb.append( getLineNumber( locator ) );
      case 2 :
      case 1 :
        sb.append( " <" ).append( elementName );
        if( attributes.getLength() > 0 )
          sb.append( javaAttributesAsString( attributes ) );
        sb.append( ">" );
        System.out.println( sb );
      case 0 :
        break;
    }
  }

  public void characters( Locator locator, final String characters )
  {
    if( characters.length() < 1 )
      return;

    StringBuilder sb = new StringBuilder();
    switch( verbosity )
    {
      case 3 :
        sb.append( getLineNumber( locator ) );
      case 2 :
      case 1 :
        sb.append( LINE_NUMBER_INDENT ).append( characters );
        System.out.println( sb );
      case 0 :
        break;
    }
  }

  public void endElement( Locator locator, final String elementName )
  {
    StringBuilder sb = new StringBuilder();
    switch( verbosity )
    {
      case 3 :
        sb.append( getLineNumber( locator ) );
      case 2 :
      case 1 :
        sb.append( " </" ).append( elementName ).append( ">" );
        System.out.println( sb );
      case 0 :
        break;
    }
  }

  public void endElement( Locator locator, final String elementName, StringBuilder text )
  {
    //noinspection DuplicatedCode
    StringBuilder sb = new StringBuilder();
    switch( verbosity )
    {
      case 3 :
        sb.append( getLineNumber( locator ) );
      case 2 :
      case 1 :
        sb.append( " </" ).append( elementName ).append( ">" );
        System.out.println( sb );
      case 0 :
        break;
    }
  }

  public void startDocument() { if( verbosity > 2 ) System.out.println( "[start of document]" ); }
  public void endDocument()   { if( verbosity > 2 ) System.out.println( "[end of document]" );   }

  private static int    LINE_NUMBER_PLACES = 3;
  private static String LINE_NUMBER_INDENT = "   ";

  public static void setLineNumberPlaces( int places ) { LINE_NUMBER_PLACES = places; }
  public static void setLineNumberIndent( int indent )
  {
    StringBuilder sb = new StringBuilder();
    while( indent-- > 0 )
      sb.append( ' ' );
    LINE_NUMBER_INDENT = sb.toString();
  }

  private static String getLineNumber( Locator locator )
  {
    return StringUtilities.padStringLeft( locator.getLineNumber()+"", LINE_NUMBER_PLACES );
  }

  private static String javaAttributesAsString( Attributes attributes )
  {
    Map< String, String > javaAttributes = getAttributesAsJavaMap( attributes );

    if( javaAttributes.size() == 0 )
      return "";

    StringBuilder sb = new StringBuilder();

    for( Map.Entry< String, String > attribute : javaAttributes.entrySet() )
      sb.append( " " ).append( attribute.getKey() ).append( "=\"" ).append( attribute.getValue() ).append( "\"" );

    return sb.toString();
  }

  private static Map< String, String > getAttributesAsJavaMap( Attributes attributes )
  {
    int                   attributeLength = attributes.getLength();
    Map< String, String > javaAttributes  = new HashMap<>( attributeLength );

    for( int count = 0; count < attributeLength; count++ )
    {
      String attribute = attributes.getQName( count );
      String value     = attributes.getValue( count );
      javaAttributes.put( attribute, value );
    }

    return javaAttributes;
  }
}

package com.windofkeltia.sax;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.XMLReader;

import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TestName;

public class SampleHandlerTest
{
  private static final String CONTENT_PATH = TestUtilities.TEST_FODDER + "sample.xml";

  @Test
  public void test() throws Exception
  {
    SampleHandler.setPrinterVerbosity( 3 );

    SAXParserFactory factory = SAXParserFactory.newInstance();
    SAXParser        parser  = factory.newSAXParser();
    XMLReader        reader  = parser.getXMLReader();
    SampleHandler    handler = new SampleHandler();

    parser.parse( CONTENT_PATH, handler );
  }
}