package com.xml.tutorial;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;

/**
* A handler for SAX parser events that outputs certain event
* information to standard output.
*
* @author mlorenz
*/
public class SAXEcho extends DefaultHandler {
public static final String XML_DOCUMENT_DTD = "catalogDTD.xml";
//validates via catalog.dtd
public static final String XML_DOCUMENT_XSD = "catalogXSD.xml";
//validates via catalog.xsd
public static final String NEW_LINE = System.getProperty("line.separator");
protected static Writer writer;
/**
* Constructor
*/
public SAXEcho() {
super();
}
/**
* @param args
*/
public static void main(String[] args) {
//-- Set up my instance to handle SAX events
DefaultHandler eventHandler = new SAXEcho();
//-- Echo to standard output
writer = new OutputStreamWriter( System.out );
try {
//-- Create a SAX parser
XMLReader parser = XMLReaderFactory.createXMLReader();
parser.setContentHandler( eventHandler );
parser.setErrorHandler( eventHandler );
parser.setFeature(
"http://xml.org/sax/features/validation", true );
//-- Validation via DTD --
echo( "=== Parsing " + XML_DOCUMENT_DTD + " ===" + NEW_LINE );
//-- Parse my XML document, reporting DTD-related errors
parser.parse( XML_DOCUMENT_DTD );
//-- Validation via XSD --
parser.setFeature(
"http://apache.org/xml/features/validation/schema",
true );
echo( NEW_LINE + NEW_LINE + "=== Parsing " +
XML_DOCUMENT_XSD + " ===" + NEW_LINE );
//-- Parse my XML document, reporting XSD-related errors
parser.parse( XML_DOCUMENT_XSD );
} catch (SAXException e) {
System.out.println( "Parsing Exception occurred" );
e.printStackTrace();
} catch (IOException e) {
System.out.println( "Could not read the file" );
e.printStackTrace();
}
System.exit(0);
}
//--Implement SAX callback events of interest (default is do nothing) --
/* (non-Javadoc)
* @see org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String,
* java.lang.String, java.lang.String, org.xml.sax.Attributes)
* @see org.xml.sax.ContentHandler interface
* Element and its attributes
*/
@Override
public void startElement( String uri,
String localName,
String qName,
Attributes attributes)
throws SAXException {
if( localName.length() == 0 )
echo( "<" + qName );
else
echo( "<" + localName );
if( attributes != null ) {
for( int i=0; i < attributes.getLength(); i++ ) {
if( attributes.getLocalName(i).length() == 0 ) {
echo( " " + attributes.getQName(i) +
"=\"" + attributes.getValue(i) + "\"" );
}
}
}
echo( ">" );
}
/* (non-Javadoc)
* @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String,
* java.lang.String, java.lang.String)
* End tag
*/
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
echo( "</" + qName + ">" );
}
/* (non-Javadoc)
* @see org.xml.sax.helpers.DefaultHandler#characters(char[], int, int)
* Character data inside an element
*/
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
String s = new String(ch, start, length);
echo(s);
}
//-- Add additional event echoing at your discretion --
/**
* Output aString to standard output
* @param aString
*/
protected static void echo( String aString ) {
try {
writer.write( aString );
writer.flush();
} catch (IOException e) {
System.out.println( "I/O error during echo()" );
e.printStackTrace();
}
}
/* (non-Javadoc)
* @see org.xml.sax.helpers.DefaultHandler#error(org.xml.sax.SAXParseException)
* @see org.xml.sax.ErrorHandler interface
*/
@Override
public void error(SAXParseException e) throws SAXException {
echo( NEW_LINE + "*** Failed validation ***" + NEW_LINE );
super.error(e);
echo( "* " + e.getMessage() + NEW_LINE +
"* Line " + e.getLineNumber() +
" Column " + e.getColumnNumber() + NEW_LINE +
"*************************" + NEW_LINE );
try {
Thread.sleep( 10 );
} catch (InterruptedException e1) {
e1.printStackTrace();
}
}
}

=== Parsing catalogDTD.xml ===
<catalog><dvd><title>Terminator 2</title><description>
A shape-shifting cyborg is sent back from the future to kill the leader of the resistance.
</description><price>19.95</price><year>1991</year>
</dvd><dvd><title>The Matrix</title><price>10.95</price>

<year>1999</year></dvd><dvd><title>Life as a House</title><description>
When a man is diagnosed with terminal cancer,
he takes custody of his misanthropic teenage son.
</description><price>15.95</price><year>2001</year>
</dvd><dvd><title>Raiders of the Lost Ark</title><price>

14.95</price><year>1981</year></dvd></catalog>

=== Parsing catalogXSD.xml ===
<catalog>
<dvd>
<title>Terminator 2</title>
<description>
A shape-shifting cyborg is sent back from the future to kill the leader of the resistance.
</description>
<price>19.95</price>
<year>1991</year>
</dvd>
<dvd>
<title>The Matrix</title>
<price>10.95</price>
<year>1999</year>
</dvd>
<dvd>
<title>Life as a House</title>
<description>
When a man is diagnosed with terminal cancer,
he takes custody of his misanthropic teenage son.
</description>
<price>15.95</price>
<year>2001</year>
</dvd>
<dvd>
<title>Raiders of the Lost Ark</title>
<price>14.95</price>
<year>1981</year>
</dvd>
</catalog>

=== Parsing catalogDTD.xml ===
<catalog><dvd><title>Terminator 2</title><description>
A shape-shifting cyborg is sent back from the future to kill the leader of the resistance.
</description><price>19.95</price><year>1991</year>
</dvd><dvd><title>The Matrix</title><price>10.95
</price><year>1999</year></dvd><dvd><title>Life as a House</title><description>
When a man is diagnosed with terminal cancer,
he takes custody of his misanthropic teenage son.
</description><year>2001</year>
*** Failed validation ***
* The content of element type "dvd" must match "(title,description?,price,year)".
*************************
</dvd><dvd><title>Raiders of the Lost Ark</title><price>14.95</price><year>1981</year></dvd></catalog>
=== Parsing catalogXSD.xml ===
<catalog>

<dvd>
<title>Terminator 2</title>
<description>
A shape-shifting cyborg is sent back from the future to kill the leader of the resistance.
</description>
<price>19.95</price>
<year>1991</year>
</dvd>
<dvd>
<title>The Matrix</title>
<price>10.95</price>
<year>1999</year>
</dvd>
<dvd>
<title>Life as a House</title>
<description>
When a man is diagnosed with terminal cancer,
he takes custody of his misanthropic teenage son.
</description>


*** Failed validation ***
* cvc-complex-type.2.4.a: Invalid content was found starting with element 'year'. One of '{"":price}' is expected.
*************************
<year>2001</year>
</dvd>
<dvd>
<title>Raiders of the Lost Ark</title>
<price>14.95</price>
<year>1981</year>
</dvd>
</catalog>

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema elementFormDefault="qualified" xml:lang="EN"
xmlns:xs="http://www.w3.org/2001/XMLSchema">

<!-- Our DVD catalog contains four or more DVDs -->
<xs:element name="catalog">
<xs:complexType>
<xs:sequence minOccurs="4" maxOccurs="unbounded">
<xs:element ref="dvd"/>
</xs:sequence>
</xs:complexType>
</xs:element>

<!-- DVDs have a title, an optional description, a price, and a release year -->
<xs:element name="dvd">
<xs:complexType>
<xs:sequence>
<xs:element name="title" type="xs:string"/>
<xs:element name="description" type="descriptionString"
minOccurs="0"/>
<xs:element name="price" type="priceValue"/>
<xs:element name="year" type="yearString"/>
</xs:sequence>
<xs:attribute name="code" type="xs:ID"/> <!-- requires a unique ID -->
<xs:attribute name="genre"> <!-- default = optional -->
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="Drama"/>
<xs:enumeration value="Comedy"/>
<xs:enumeration value="SciFi"/>
<xs:enumeration value="Action"/>
<xs:enumeration value="Romance"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:complexType>
</xs:element>

<!-- Descriptions must be between 10 and 120 characters long -->
<xs:simpleType name="descriptionString">
<xs:restriction base="xs:string">
<xs:minLength value="10"/>
<xs:maxLength value="120"/>
</xs:restriction>
</xs:simpleType>

<!-- Price must be < 100.00 -->
<xs:simpleType name="priceValue">
<xs:restriction base="xs:decimal">
<xs:totalDigits value="4"/>
<xs:fractionDigits value="2"/>
<xs:maxExclusive value="100.00"/>
</xs:restriction>
</xs:simpleType>

<!-- Year must be 4 digits, between 1900 and 2099 -->
<xs:simpleType name="yearString">
<xs:restriction base="xs:string">
<xs:pattern value="(19|20)\d\d"/>
</xs:restriction>
</xs:simpleType>
</xs:schema>

xs:complexType 和 xs:simpleType。complexType 元素可以包含其他元素或属性：

<xs:element name="dvd">
<xs:complexType>
<xs:sequence>
<xs:element name="title" type="xs:string"/>
...

<!-- Price must be < 100.00 -->
<xs:simpleType name="priceValue">
<xs:restriction base="xs:decimal">
<xs:totalDigits value="4"/>
<xs:fractionDigits value="2"/>
<xs:maxExclusive value="100.00"/>
</xs:restriction>
</xs:simpleType>

<!-- Year must be 4 digits, between 1900 and 2099 -->
<xs:simpleType name="yearString">
<xs:restriction base="xs:string">
<xs:pattern value="(19|20)\d\d"/>
</xs:restriction>
</xs:simpleType>

dvdTitles.xq:

<html>
<body>
Available DVDs:
<br/>
<ol>
{
for $title in doc("dvd.xml")/catalog/dvd/title
order by $title
return <li>{data($title)}</li>
}
</ol>
</body>
</html>

dvdTitles.html:

<?xml version="1.0" encoding="UTF-8"?>
<html>
<body>
Available DVDs:
<br/>
<ol>
<li>Life as a House</li>
<li>Raiders of the Lost Ark</li>
<li>Terminator 2</li>
<li>The Matrix</li>
</ol>
</body>
</html>

dvdPriceThreshold.hq

<html>
<body>
DVDs prices below $15.00:
<br/>
<ol>
{
for $price in doc("dvd.xml")/catalog/dvd/price
where $price < 15.00
order by
$price
descending
return <li>{data($price)}</li>
}
</ol>
</body>
</html>

dvdPrices.html

<?xml version="1.0" encoding="UTF-8"?>
<html>
<body>
DVDs prices below $15.00:
<br/>
<ol>
<li>14.95</li>
<li>12.95</li>
</ol>
</body>
</html>