Java Tutorial/XML/SAX

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Accessing features of the SAX parser implementation

   <source lang="java">

import javax.xml.parsers.SAXParserFactory; public class Main { 

 public static void main(String[] argv) throws Exception {
   SAXParserFactory factory = SAXParserFactory.newInstance();
   String features[] = { "http://xml.org/sax/features/namespaces",
       "http://xml.org/sax/features/namespace-prefixes",
       "http://xml.org/sax/features/string-interning", "http://xml.org/sax/features/validation",
       "http://xml.org/sax/features/external-general-entities",
       "http://xml.org/sax/features/external-parameter-entities",
       "http://xml.org/sax/features/lexical-handler/parameter-entities", };
   for (int i = 0; i < features.length; i++) {
     System.out.print("\t- "" + features[i] + "" is ");
     System.out.println(""" + factory.getFeature(features[i]) + """);
   }
 }

}</source>





A Class to Convert SAX Parse Information into an XML Document

   <source lang="java">

import java.io.FileOutputStream; import java.io.IOException; import java.io.PrintWriter; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; public class SAXCopy { 

 static public void main(String[] arg) {
   try {
     SAXParserFactory spf = SAXParserFactory.newInstance();
     SAXParser parser = spf.newSAXParser();
     XMLReader reader = parser.getXMLReader();
     reader.setErrorHandler(new MyErrorHandler());
     MyCopyHandler duper = new MyCopyHandler();
     reader.setContentHandler(duper);
     InputSource is = new InputSource("test.xml");
     reader.parse(is);
   } catch (SAXException e) {
     System.exit(1);
   } catch (ParserConfigurationException e) {
     System.err.println(e);
     System.exit(1);
   } catch (IOException e) {
     System.err.println(e);
     System.exit(1);
   }
 }

} class MyErrorHandler implements ErrorHandler { 

 public void warning(SAXParseException e) throws SAXException {
   show("Warning", e);
   throw (e);
 }
 public void error(SAXParseException e) throws SAXException {
   show("Error", e);
   throw (e);
 }
 public void fatalError(SAXParseException e) throws SAXException {
   show("Fatal Error", e);
   throw (e);
 }
 private void show(String type, SAXParseException e) {
   System.out.println(type + ": " + e.getMessage());
   System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
   System.out.println("System ID: " + e.getSystemId());
 }

} class MyCopyHandler implements ContentHandler { 

 private boolean namespaceBegin = false;
 private String currentNamespace;
 private String currentNamespaceUri;
 private Locator locator;
 public MyCopyHandler() {
 }
 public void setDocumentLocator(Locator locator) {
   this.locator = locator;
 }
 public void startDocument() {
   System.out.println("<?xml version=\"1.0\"?>");
   System.out.println();
 }
 public void endDocument() {
 }
 public void startPrefixMapping(String prefix, String uri) {
   namespaceBegin = true;
   currentNamespace = prefix;
   currentNamespaceUri = uri;
 }
 public void endPrefixMapping(String prefix) {
 }
 public void startElement(String namespaceURI, String localName, String qName, Attributes atts) {
   System.out.println("<" + qName);
   if (namespaceBegin) {
     System.out.print(" xmlns:" + currentNamespace + "=\"" + currentNamespaceUri + "\"");
     namespaceBegin = false;
   }
   for (int i = 0; i < atts.getLength(); i++) {
     System.out.print(" " + atts.getQName(i) + "=\\" + atts.getValue(i) + "\"");
   }
   System.out.print(">");
 }
 public void endElement(String namespaceURI, String localName, String qName) {
   System.out.print("</" + qName + ">");
 }
 public void characters(char[] ch, int start, int length) {
   for (int i = start; i < start + length; i++)
     System.out.print(ch[i]);
 }
 public void ignorableWhitespace(char[] ch, int start, int length) {
   for (int i = start; i < start + length; i++)
     System.out.print(ch[i]);
 }
 public void processingInstruction(String target, String data) {
   System.out.print("<?" + target + " " + data + "?>");
 }
 public void skippedEntity(String name) {
   System.out.print("&" + name + ";");
 }

}</source> 



<?xml version="1.0"?>
<roots
>
  <a
>
    <b
>text
  </a>
</roots>


A Content Handler to Output a Sorted List

   <source lang="java">

/* Code revised from Java, XML, and JAXP by Arthur Griffith John Wiley & Sons 2002

  • /

import java.io.IOException; import java.io.PrintWriter; import java.util.Vector; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; public class MappingContentHandler { 

 static public void main(String[] arg) {
   try {
     SAXParserFactory spf = SAXParserFactory.newInstance();
     SAXParser parser = spf.newSAXParser();
     XMLReader reader = parser.getXMLReader();
     reader.setErrorHandler(new MyErrorHandler());
     MyTextHandler duper = new MyTextHandler();
     reader.setContentHandler(duper);
     InputSource is = new InputSource("person.xml");
     reader.parse(is);
   } catch (SAXException e) {
     System.out.println(e);
   } catch (ParserConfigurationException e) {
     System.err.println(e);
     System.exit(1);
   } catch (IOException e) {
     System.err.println(e);
     System.exit(1);
   }
 }

} class MyErrorHandler implements ErrorHandler { 

 public void warning(SAXParseException e) throws SAXException {
   show("Warning", e);
   throw (e);
 }
 public void error(SAXParseException e) throws SAXException {
   show("Error", e);
   throw (e);
 }
 public void fatalError(SAXParseException e) throws SAXException {
   show("Fatal Error", e);
   throw (e);
 }
 private void show(String type, SAXParseException e) {
   System.out.println(type + ": " + e.getMessage());
   System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
   System.out.println("System ID: " + e.getSystemId());
 }

} class MyTextHandler implements ContentHandler { 

 private boolean insideNameElement = false;
 private boolean insidePhoneElement = false;
 private boolean insideEmailElement = false;
 private Person person;
 private Vector<Person> personVec;
 public MyTextHandler() {
     personVec = new Vector<Person>();
 }
 public void setDocumentLocator(Locator locator) {
 }
 public void startDocument() {
 }
 public void endDocument() {
     for(int i=0; i<personVec.size(); i++) {
         Person p = (Person)personVec.elementAt(i);
         System.out.println(p.getName()+" "+p.getPhone()+" "+p.getEmail());
     }
 }
 public void startPrefixMapping(String prefix,String uri) { }
 public void endPrefixMapping(String prefix)  { }
 public void startElement(String namespaceURI,String localName,
         String qName,Attributes atts) {
     if(qName.equals("person")) {
         person = new Person();
     } else if(qName.equals("name")) {
         insideNameElement = true;
     } else if(qName.equals("phone")) {
         insidePhoneElement = true;
     } else if(qName.equals("email")) {
         insideEmailElement = true;
     }
 }
 public void endElement(String namespaceURI,String localName,
         String qName) {
     if(qName.equals("person")) {
         if(person != null){
             personVec.addElement(person);
         }
     } else if(qName.equals("name")) {
         insideNameElement = false;
     } else if(qName.equals("phone")) {
         insidePhoneElement = false;
     } else if(qName.equals("email")) {
         insideEmailElement = false;
     }
 }
 public void characters(char[] ch,int start,int length) {
     String str = "";
     for(int i=start; i<start + length; i++)
         str += ch[i];
     if(insideNameElement)
         person.setName(str);
     else if(insidePhoneElement)
         person.setPhone(str);
     else if(insideEmailElement)
         person.setEmail(str);
 }
 public void ignorableWhitespace(char[] ch,int start,int length) { }
 public void processingInstruction(String target,String data) { }
 public void skippedEntity(String name) { }

} class Person { 

 private String name = null;
 private String phone = null;
 private String email = null;
 public void setName(String value) {
     name = value;
 }
 public void setPhone(String value) {
     phone = value;
 }
 public void setEmail(String value) {
     email = value;
 }
 public String getName() {
     if(name == null)
         return("none");
     return(name);
 }
 public String getPhone() {
     if(phone == null)
         return("none");
     return(phone);
 }
 public String getEmail() {
     if(email == null)
         return("none");
     return(email);
 }

}</source> 



R, L 999 555-8888 e@yoursite.net
V, R 333 555-9910 rv@yoursite.ru
B, D. none b@xyz.net
B, M 502 555-2192 none


A Program to Display the Input from a SAX Parser: subclass ContentHandler

   <source lang="java">

/* Code revised from Java, XML, and JAXP by Arthur Griffith John Wiley & Sons 2002

  • /

import java.io.IOException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; class MyContentHandler implements ContentHandler { 

 private Locator locator;
 public void setDocumentLocator(Locator locator) {
   this.locator = locator;
   System.out.println("-" + locator.getLineNumber() + "---Document ID: " + locator.getSystemId());
 }
 public void startDocument() {
   System.out.println("-" + locator.getLineNumber() + "---Document parse started");
 }
 public void endDocument() {
   System.out.println("-" + locator.getLineNumber() + "---Document parse ended");
 }
 public void startPrefixMapping(String prefix, String uri) {
   System.out.println("-" + locator.getLineNumber() + "---Namespace scope begins");
   System.out.println("     " + prefix + "=\"" + uri + "\"");
 }
 public void endPrefixMapping(String prefix) {
   System.out.println("-" + locator.getLineNumber() + "---Namespace scope ends");
   System.out.println("     " + prefix);
 }
 public void startElement(String namespaceURI, String localName, String qName, Attributes atts) {
   System.out.println("-" + locator.getLineNumber() + "---Opening tag of an element");
   System.out.println("       Namespace: " + namespaceURI);
   System.out.println("      Local name: " + localName);
   System.out.println("  Qualified name: " + qName);
   for (int i = 0; i < atts.getLength(); i++) {
     System.out.println("       Attribute: " + atts.getQName(i) + "=\"" + atts.getValue(i) + "\"");
   }
 }
 public void endElement(String namespaceURI, String localName, String qName) {
   System.out.println("-" + locator.getLineNumber() + "---Closing tag of an element");
   System.out.println("       Namespace: " + namespaceURI);
   System.out.println("      Local name: " + localName);
   System.out.println("  Qualified name: " + qName);
 }
 public void characters(char[] ch, int start, int length) {
   System.out.println("-" + locator.getLineNumber() + "---Character data");
   showCharacters(ch, start, length);
 }
 public void ignorableWhitespace(char[] ch, int start, int length) {
   System.out.println("-" + locator.getLineNumber() + "---Whitespace");
   showCharacters(ch, start, length);
 }
 public void processingInstruction(String target, String data) {
   System.out.println("-" + locator.getLineNumber() + "---Processing Instruction");
   System.out.println("         Target: " + target);
   System.out.println("           Data: " + data);
 }
 public void skippedEntity(String name) {
   System.out.println("-" + locator.getLineNumber() + "---Skipped Entity");
   System.out.println("           Name: " + name);
 }
 public void showCharacters(char[] ch, int start, int length) {
   System.out.print("        \"");
   for (int i = start; i < start + length; i++)
     switch (ch[i]) {
     case "\n":
       System.out.print("\\n");
       break;
     case "\r":
       System.out.print("\\r");
       break;
     case "\t":
       System.out.print("\\t");
       break;
     default:
       System.out.print(ch[i]);
       break;
     }
   System.out.println("\"");
 }

} class MyErrorHandler implements ErrorHandler { 

 public void warning(SAXParseException e) throws SAXException {
   show("Warning", e);
   throw (e);
 }
 public void error(SAXParseException e) throws SAXException {
   show("Error", e);
   throw (e);
 }
 public void fatalError(SAXParseException e) throws SAXException {
   show("Fatal Error", e);
   throw (e);
 }
 private void show(String type, SAXParseException e) {
   System.out.println(type + ": " + e.getMessage());
   System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
   System.out.println("System ID: " + e.getSystemId());
 }

} public class SAXDump { 

 static public void main(String[] arg) {
   SAXParserFactory spf = SAXParserFactory.newInstance();
   XMLReader reader = null;
   try {
     SAXParser parser = spf.newSAXParser();
     reader = parser.getXMLReader();
   } catch (Exception e) {
     System.err.println(e);
     System.exit(1);
   }
   reader.setErrorHandler(new MyErrorHandler());
   reader.setContentHandler(new MyContentHandler());
   try {
     InputSource is = new InputSource("test.xml");
     reader.parse(is);
   } catch (SAXException e) {
     System.exit(1);
   } catch (IOException e) {
     System.err.println(e);
     System.exit(1);
   }
 }

}</source> 



-1---Document ID: file:///C:/Java_Dev/eclipse31/Eclipse/test.xml
-1---Document parse started
-1---Opening tag of an element
       Namespace: 
      Local name: 
  Qualified name: roots
-2---Character data
        "\n  "
-2---Opening tag of an element
       Namespace: 
      Local name: 
  Qualified name: a
-3---Character data
        "\n    "
-3---Opening tag of an element
       Namespace: 
      Local name: 
  Qualified name: b
-3---Character data
        "text"
-3---Closing tag of an element
       Namespace: 
      Local name: 
  Qualified name: b
-4---Character data
        "\n  "
-4---Closing tag of an element
       Namespace: 
      Local name: 
  Qualified name: a
-5---Character data
        "\n"
-5---Closing tag of an element
       Namespace: 
      Local name: 
  Qualified name: roots
-6---Document parse ended


Calling a .NET Web Service

   <source lang="java">

import java.io.BufferedReader; import java.io.File; import java.io.InputStreamReader; import java.net.URL; import javax.xml.transform.Source; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerFactory; import javax.xml.transform.sax.SAXSource; import javax.xml.transform.stream.StreamResult; import javax.xml.transform.stream.StreamSource; import org.xml.sax.InputSource; public class Main { 

 public static void main(String[] args) throws Exception {
   URL webSvcGetURL = new URL("http://www.server.net/Webservices");
   BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(webSvcGetURL
       .openStream()));
   SAXSource saxSource = new SAXSource(new InputSource(bufferedReader));
   String curDir = new File(".").getCanonicalPath();
   StreamSource xlstStreamSource = new StreamSource(new File(curDir + File.separator + "style.xsl"));
   File resultHTMLFile = new File(curDir + File.separator + "output.html");
   StreamResult streamResult = new StreamResult(resultHTMLFile);
   TransformerFactory factory = TransformerFactory.newInstance();
   Transformer transformer = factory.newTransformer(xlstStreamSource);
   transformer.transform((Source) saxSource, streamResult);
 }

}</source>





Configuring SAX parser factory to produce alternate parser

   <source lang="java">

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; public class Main { 

 public static void main(String[] args) throws Exception {
   System.setProperty("avax.xml.parsers.SAXParserFactory", "org.apache.xerces.parsers.SAXParser");
   SAXParserFactory factory = SAXParserFactory.newInstance();
   SAXParser parser = factory.newSAXParser();
 }

}</source>





Generating SAX Parsing Events by Traversing a DOM Document

   <source lang="java">

import java.io.File; import java.net.URI; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.transform.Source; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.sax.SAXResult; import org.w3c.dom.Document; import org.xml.sax.helpers.DefaultHandler; public class Main { 

 public static void main(String[] argv) throws Exception {
   DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
   factory.setValidating(true);
   factory.setExpandEntityReferences(false);
   Document doc = factory.newDocumentBuilder().parse(new File("filename"));
   Source source = new DOMSource(doc);
   URI uri = new File("infilename.xml").toURI();
   source.setSystemId(uri.toString());
   DefaultHandler handler = new MyHandler();
   SAXResult result = new SAXResult(handler);
   Transformer xformer = TransformerFactory.newInstance().newTransformer();
   xformer.transform(source, result);
 }

} class MyHandler extends DefaultHandler { }</source>





Handling SAX errors during parsing

   <source lang="java">

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.helpers.DefaultHandler; public class Main { 

 public static void main(String[] argv) throws Exception {
   SAXParserFactory factory = SAXParserFactory.newInstance();
   factory.setValidating(true);
   SAXParser parser = factory.newSAXParser();
   SaxHandler handler = new SaxHandler();
   parser.parse("sample.xml", handler);
 }

} class SaxHandler extends DefaultHandler { 

 public void startElement(String uri, String localName, String qName, Attributes attrs)
     throws SAXException {
   if (qName.equals("order")) {
   }
 }
 public void error(SAXParseException ex) throws SAXException {
   System.out.println("ERROR: [at " + ex.getLineNumber() + "] " + ex);
 }
 public void fatalError(SAXParseException ex) throws SAXException {
   System.out.println("FATAL_ERROR: [at " + ex.getLineNumber() + "] " + ex);
 }
 public void warning(SAXParseException ex) throws SAXException {
   System.out.println("WARNING: [at " + ex.getLineNumber() + "] " + ex);
 }

}</source>





Intercepting All Accesses to External Entities During XML SAX Parsing

   <source lang="java">

import java.io.File; import java.io.FileReader; import java.net.URI; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; import org.xml.sax.EntityResolver; import org.xml.sax.InputSource; public class Main { 

 public static void main(String[] argv) throws Exception {
   DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
   builder.setEntityResolver(new MyResolver());
   Document doc = builder.parse(new File("infilename.xml"));
 }

} class MyResolver implements EntityResolver { 

 public InputSource resolveEntity(String publicId, String systemId) {
   try {
     URI uri = new URI(systemId);
     if ("file".equals(uri.getScheme())) {
       String filename = uri.getSchemeSpecificPart();
       return new InputSource(new FileReader(filename));
     }
   } catch (Exception e) {
   }
   return null;
 }

}</source>





Parsing XML with a simple SAX document handler

   <source lang="java">

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; public class Main { 

 public static void main(String[] argv) throws Exception {
   SAXParserFactory factory = SAXParserFactory.newInstance();
   SAXParser parser = factory.newSAXParser();
   SaxHandler handler = new SaxHandler();
   parser.parse("sample.xml", handler);
 }

} class SaxHandler extends DefaultHandler { 

 public void startDocument() throws SAXException {
   System.out.println("Document processing started");
 }
 public void endDocument() throws SAXException {
   System.out.println("Document processing finished");
 }
 public void startElement(String uri, String localName, String qName, Attributes attrs)
     throws SAXException {
   if (qName.equals("order")) {
   } else if (qName.equals("date")) {
   } else {
     throw new IllegalArgumentException("Element "" + qName + "" is not allowed here");
   }
 }
 public void endElement(String uri, String localName, String qName) throws SAXException {
 }

}</source>





Produce a SAX stream from a DOM Document

   <source lang="java">

/* 

* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

/* $Id: DOM2SAX.java 627367 2008-02-13 12:03:30Z maxberger $ */

import java.util.List; import java.util.Map; import java.util.Stack; import org.w3c.dom.Document; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; import org.xml.sax.ContentHandler; import org.xml.sax.SAXException; import org.xml.sax.ext.LexicalHandler; import org.xml.sax.helpers.AttributesImpl; /** 

* Helper class that produces a SAX stream from a DOM Document.
*

* Part of the code here copied and adapted from Apache Xalan-J, * src/org/apache/xalan/xsltc/trax/DOM2SAX.java */ public class DOM2SAX { private static final String EMPTYSTRING = ""; private static final String XMLNS_PREFIX = "xmlns"; private ContentHandler contentHandler; private LexicalHandler lexicalHandler; private Map prefixes = new java.util.HashMap(); /** * Main constructor * @param handler the ContentHandler to send SAX events to */ public DOM2SAX(ContentHandler handler) { this.contentHandler = handler; if (handler instanceof LexicalHandler) { this.lexicalHandler = (LexicalHandler)handler; } } /** * Writes the given document using the given ContentHandler. * @param doc DOM document * @param fragment if false no startDocument() and endDocument() calls are issued. * @throws SAXException In case of a problem while writing XML */ public void writeDocument(Document doc, boolean fragment) throws SAXException { if (!fragment) { contentHandler.startDocument(); } for (Node n = doc.getFirstChild(); n != null; n = n.getNextSibling()) { writeNode(n); } if (!fragment) { contentHandler.endDocument(); } } /** * Begin the scope of namespace prefix. Forward the event to the SAX handler * only if the prefix is unknown or it is mapped to a different URI. */ private boolean startPrefixMapping(String prefix, String uri) throws SAXException { boolean pushed = true; Stack uriStack = (Stack)prefixes.get(prefix); if (uriStack != null) { if (uriStack.isEmpty()) { contentHandler.startPrefixMapping(prefix, uri); uriStack.push(uri); } else { final String lastUri = (String) uriStack.peek(); if (!lastUri.equals(uri)) { contentHandler.startPrefixMapping(prefix, uri); uriStack.push(uri); } else { pushed = false; } } } else { contentHandler.startPrefixMapping(prefix, uri); uriStack = new Stack(); prefixes.put(prefix, uriStack); uriStack.push(uri); } return pushed; } /* * End the scope of a name prefix by popping it from the stack and passing * the event to the SAX Handler. */ private void endPrefixMapping(String prefix) throws SAXException { final Stack uriStack = (Stack)prefixes.get(prefix); if (uriStack != null) { contentHandler.endPrefixMapping(prefix); uriStack.pop(); } } /** * If the DOM was created using a DOM 1.0 API, the local name may be null. * If so, get the local name from the qualified name before generating the * SAX event. */ private static String getLocalName(Node node) { final String localName = node.getLocalName(); if (localName == null) { final String qname = node.getNodeName(); final int col = qname.lastIndexOf(":"); return (col > 0) ? qname.substring(col + 1) : qname; } return localName; } /** * Writes a node using the given writer. * @param node node to serialize * @throws SAXException In case of a problem while writing XML */ private void writeNode(Node node) throws SAXException { if (node == null) { return; } switch (node.getNodeType()) { case Node.ATTRIBUTE_NODE: // handled by ELEMENT_NODE case Node.DOCUMENT_FRAGMENT_NODE: case Node.DOCUMENT_TYPE_NODE: case Node.ENTITY_NODE: case Node.ENTITY_REFERENCE_NODE: case Node.NOTATION_NODE: // These node types are ignored!!! break; case Node.CDATA_SECTION_NODE: final String cdata = node.getNodeValue(); if (lexicalHandler != null) { lexicalHandler.startCDATA(); contentHandler.characters(cdata.toCharArray(), 0, cdata.length()); lexicalHandler.endCDATA(); } else { // in the case where there is no lex handler, we still // want the text of the cdate to make its way through. contentHandler.characters(cdata.toCharArray(), 0, cdata.length()); } break; case Node.ruMENT_NODE: // should be handled!!! if (lexicalHandler != null) { final String value = node.getNodeValue(); lexicalHandler.rument(value.toCharArray(), 0, value.length()); } break; case Node.DOCUMENT_NODE: contentHandler.startDocument(); Node next = node.getFirstChild(); while (next != null) { writeNode(next); next = next.getNextSibling(); } contentHandler.endDocument(); break; case Node.ELEMENT_NODE: String prefix; List pushedPrefixes = new java.util.ArrayList(); final AttributesImpl attrs = new AttributesImpl(); final NamedNodeMap map = node.getAttributes(); final int length = map.getLength(); // Process all namespace declarations for (int i = 0; i < length; i++) { final Node attr = map.item(i); final String qnameAttr = attr.getNodeName(); // Ignore everything but NS declarations here if (qnameAttr.startsWith(XMLNS_PREFIX)) { final String uriAttr = attr.getNodeValue(); final int colon = qnameAttr.lastIndexOf(":"); prefix = (colon > 0) ? qnameAttr.substring(colon + 1)  : EMPTYSTRING; if (startPrefixMapping(prefix, uriAttr)) { pushedPrefixes.add(prefix); } } } // Process all other attributes for (int i = 0; i < length; i++) { final Node attr = map.item(i); final String qnameAttr = attr.getNodeName(); // Ignore NS declarations here if (!qnameAttr.startsWith(XMLNS_PREFIX)) { final String uriAttr = attr.getNamespaceURI(); // Uri may be implicitly declared if (uriAttr != null) { final int colon = qnameAttr.lastIndexOf(":"); prefix = (colon > 0) ? qnameAttr.substring(0, colon)  : EMPTYSTRING; if (startPrefixMapping(prefix, uriAttr)) { pushedPrefixes.add(prefix); } } // Add attribute to list attrs.addAttribute(attr.getNamespaceURI(), getLocalName(attr), qnameAttr, "CDATA", attr .getNodeValue()); } } // Now process the element itself final String qname = node.getNodeName(); final String uri = node.getNamespaceURI(); final String localName = getLocalName(node); // Uri may be implicitly declared if (uri != null) { final int colon = qname.lastIndexOf(":"); prefix = (colon > 0) ? qname.substring(0, colon) : EMPTYSTRING; if (startPrefixMapping(prefix, uri)) { pushedPrefixes.add(prefix); } } // Generate SAX event to start element contentHandler.startElement(uri, localName, qname, attrs); // Traverse all child nodes of the element (if any) next = node.getFirstChild(); while (next != null) { writeNode(next); next = next.getNextSibling(); } // Generate SAX event to close element contentHandler.endElement(uri, localName, qname); // Generate endPrefixMapping() for all pushed prefixes final int nPushedPrefixes = pushedPrefixes.size(); for (int i = 0; i < nPushedPrefixes; i++) { endPrefixMapping((String)pushedPrefixes.get(i)); } break; case Node.PROCESSING_INSTRUCTION_NODE: contentHandler.processingInstruction(node.getNodeName(), node.getNodeValue()); break; case Node.TEXT_NODE: final String data = node.getNodeValue(); contentHandler.characters(data.toCharArray(), 0, data.length()); break; default: //nop } } }</source>

SAX Error Checking: A Simple Implementation of the ErrorHandler Interface

   <source lang="java">

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; class MyErrorHandler implements ErrorHandler { 

 public void warning(SAXParseException e) throws SAXException {
   show("Warning", e);
   throw (e);
 }
 public void error(SAXParseException e) throws SAXException {
   show("Error", e);
   throw (e);
 }
 public void fatalError(SAXParseException e) throws SAXException {
   show("Fatal Error", e);
   throw (e);
 }
 private void show(String type, SAXParseException e) {
   System.out.println(type + ": " + e.getMessage());
   System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
   System.out.println("System ID: " + e.getSystemId());
 }

} // Installation and Use of an Error Handler in a SAX Parser public class SAXCheck { 

 static public void main(String[] arg) throws Exception {
   boolean validate = false;
   validate = true;
   SAXParserFactory spf = SAXParserFactory.newInstance();
   spf.setValidating(validate);
   XMLReader reader = null;
   SAXParser parser = spf.newSAXParser();
   reader = parser.getXMLReader();
   reader.setErrorHandler(new MyErrorHandler());
   InputSource is = new InputSource("test.xml");
   reader.parse(is);
 }

}</source>





SAX parer with all its action displayed

   <source lang="java">

import java.io.File; import java.io.IOException; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; public class TrySAX extends DefaultHandler { 

 public static void main(String args[]) {
   if (args.length == 0) {
     System.out.println("No file to process. Usage is:" + "\njava TrySAX <filename>");
     return;
   }
   File xmlFile = new File(args[0]);
   handler = new TrySAX();
   handler.process(xmlFile);
 }
 private void process(File file) {
   SAXParserFactory spf = SAXParserFactory.newInstance();
   spf.setNamespaceAware(true);
   spf.setValidating(true);
   System.out.println("Parser will " + (spf.isNamespaceAware() ? "" : "not ")
       + "be namespace aware");
   System.out.println("Parser will " + (spf.isValidating() ? "" : "not ") + "validate XML");
   try {
     parser = spf.newSAXParser();
     System.out.println("Parser object is: " + parser);
   } catch (SAXException e) {
     e.printStackTrace(System.err);
     System.exit(1);
   } catch (ParserConfigurationException e) {
     e.printStackTrace(System.err);
     System.exit(1);
   }
   System.out.println("\nStarting parsing of " + file + "\n");
   try {
     parser.parse(file, this);
   } catch (IOException e) {
     e.printStackTrace(System.err);
   } catch (SAXException e) {
     e.printStackTrace(System.err);
   }
 }
 public void startDocument() {
   System.out.println("Start document: ");
 }
 public void endDocument() {
   System.out.println("End document: ");
 }
 public void startElement(String uri, String localName, String qname, Attributes attr) {
   System.out.println("Start element: local name: " + localName + " qname: " + qname + " uri: "
       + uri);
 }
 public void endElement(String uri, String localName, String qname) {
   System.out.println("End element: local name: " + localName + " qname: " + qname + " uri: "
       + uri);
 }
 public void characters(char[] ch, int start, int length) {
   System.out.println("Characters: " + new String(ch, start, length));
 }
 public void ignorableWhitespace(char[] ch, int start, int length) {
   System.out.println("Ignorable whitespace: " + new String(ch, start, length));
 }
 private static TrySAX handler = null;
 private SAXParser parser = null;

}</source>





Sax to DOM converter

   <source lang="java">

/* Copyright 2004 The Apache Software Foundation 

*
*   Licensed under the Apache License, Version 2.0 (the "License");
*   you may not use this file except in compliance with the License.
*   You may obtain a copy of the License at
*
*       http://www.apache.org/licenses/LICENSE-2.0
*
*   Unless required by applicable law or agreed to in writing, software
*   distributed under the License is distributed on an "AS IS" BASIS,
*   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*   See the License for the specific language governing permissions and
*  limitations under the License.
*/

// Revised from xmlbeans import org.w3c.dom.Node; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.ProcessingInstruction; import org.w3c.dom.rument; import org.xml.sax.Attributes; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.ContentHandler; import org.xml.sax.helpers.DefaultHandler; import org.xml.sax.ext.LexicalHandler; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.DocumentBuilderFactory; import java.util.Stack; import java.util.Vector; public class Sax2Dom 

       extends DefaultHandler
       implements ContentHandler, LexicalHandler

{ 

   public static final String EMPTYSTRING = "";
   public static final String XML_PREFIX = "xml";
   public static final String XMLNS_PREFIX = "xmlns";
   public static final String XMLNS_STRING = "xmlns:";
   public static final String XMLNS_URI = "http://www.w3.org/2000/xmlns/";
   private Node _root = null;
   private Document _document = null;
   private Stack _nodeStk = new Stack();
   private Vector _namespaceDecls = null;
   public Sax2Dom() throws ParserConfigurationException
   {
       final DocumentBuilderFactory factory =
               DocumentBuilderFactory.newInstance();
       _document = factory.newDocumentBuilder().newDocument();
       _root = _document;
   }
   public Sax2Dom(Node root) throws ParserConfigurationException
   {
       _root = root;
       if (root instanceof Document)
       {
           _document = (Document) root;
       }
       else if (root != null)
       {
           _document = root.getOwnerDocument();
       }
       else
       {
           final DocumentBuilderFactory factory =
                   DocumentBuilderFactory.newInstance();
           _document = factory.newDocumentBuilder().newDocument();
           _root = _document;
       }
   }
   public Node getDOM()
   {
       return _root;
   }
   public void characters(char[] ch, int start, int length)
   {
       final Node last = (Node) _nodeStk.peek();
       // No text nodes can be children of root (DOM006 exception)
       if (last != _document)
       {
           final String text = new String(ch, start, length);
           last.appendChild(_document.createTextNode(text));
       }
   }
   public void startDocument()
   {
       _nodeStk.push(_root);
   }
   public void endDocument()
   {
       _nodeStk.pop();
   }
   public void startElement(String namespace, String localName, String qName,
                            Attributes attrs)
   {
       final Element tmp = (Element) _document.createElementNS(namespace, qName);
       // Add namespace declarations first
       if (_namespaceDecls != null)
       {
           final int nDecls = _namespaceDecls.size();
           for (int i = 0; i < nDecls; i++)
           {
               final String prefix = (String) _namespaceDecls.elementAt(i++);
               if (prefix == null || prefix.equals(EMPTYSTRING))
               {
                   tmp.setAttributeNS(XMLNS_URI, XMLNS_PREFIX,
                           (String) _namespaceDecls.elementAt(i));
               }
               else
               {
                   tmp.setAttributeNS(XMLNS_URI, XMLNS_STRING + prefix,
                           (String) _namespaceDecls.elementAt(i));
               }
           }
           _namespaceDecls.clear();
       }
       // Add attributes to element
       final int nattrs = attrs.getLength();
       for (int i = 0; i < nattrs; i++)
       {
           if (attrs.getLocalName(i) == null)
           {
               tmp.setAttribute(attrs.getQName(i), attrs.getValue(i));
           }
           else
           {
               tmp.setAttributeNS(attrs.getURI(i), attrs.getQName(i),
                       attrs.getValue(i));
           }
       }
       // Append this new node onto current stack node
       Node last = (Node) _nodeStk.peek();
       last.appendChild(tmp);
       // Push this node onto stack
       _nodeStk.push(tmp);
   }
   public void endElement(String namespace, String localName, String qName)
   {
       _nodeStk.pop();
   }
   public void startPrefixMapping(String prefix, String uri)
   {
       if (_namespaceDecls == null)
       {
           _namespaceDecls = new Vector(2);
       }
       _namespaceDecls.addElement(prefix);
       _namespaceDecls.addElement(uri);
   }
   public void endPrefixMapping(String prefix)
   {
       // do nothing
   }
   /**
    * This class is only used internally so this method should never
    * be called.
    */
   public void ignorableWhitespace(char[] ch, int start, int length)
   {
   }
   /**
    * adds processing instruction node to DOM.
    */
   public void processingInstruction(String target, String data)
   {
       final Node last = (Node) _nodeStk.peek();
       ProcessingInstruction pi = _document.createProcessingInstruction(
               target, data);
       if (pi != null) last.appendChild(pi);
   }
   /**
    * This class is only used internally so this method should never
    * be called.
    */
   public void setDocumentLocator(Locator locator)
   {
   }
   /**
    * This class is only used internally so this method should never
    * be called.
    */
   public void skippedEntity(String name)
   {
   }

   /**
    * Lexical Handler method to create comment node in DOM tree.
    */
   public void comment(char[] ch, int start, int length)
   {
       final Node last = (Node) _nodeStk.peek();
       Comment comment = _document.createComment(new String(ch, start, length));
       if (comment != null) last.appendChild(comment);
   }
   // Lexical Handler methods- not implemented
   public void startCDATA()
   {
   }
   public void endCDATA()
   {
   }
   public void startEntity(java.lang.String name)
   {
   }
   public void endEntity(String name)
   {
   }
   public void startDTD(String name, String publicId, String systemId)
           throws SAXException
   {
   }
   public void endDTD()
   {
   }

}</source>





The XMLReader interface

   <source lang="java">

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; class MyErrorHandler implements ErrorHandler { 

 public void warning(SAXParseException e) throws SAXException {
   show("Warning", e);
   throw (e);
 }
 public void error(SAXParseException e) throws SAXException {
   show("Error", e);
   throw (e);
 }
 public void fatalError(SAXParseException e) throws SAXException {
   show("Fatal Error", e);
   throw (e);
 }
 private void show(String type, SAXParseException e) {
   System.out.println(type + ": " + e.getMessage());
   System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
   System.out.println("System ID: " + e.getSystemId());
 }

} // Installation and Use of an Error Handler in a SAX Parser public class SAXCheck { 

 static public void main(String[] arg) throws Exception {
   boolean validate = false;
   validate = true;
   SAXParserFactory spf = SAXParserFactory.newInstance();
   spf.setValidating(validate);
   XMLReader reader = null;
   SAXParser parser = spf.newSAXParser();
   reader = parser.getXMLReader();
   reader.setErrorHandler(new MyErrorHandler());
   reader.parse("http://yourURL/TextDoc3.xml");
 }

}</source>





Using XML locator to indicate current parser position

   <source lang="java">

import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; class SampleOfXmlLocator extends DefaultHandler { 

 private Locator locator;
 public void setDocumentLocator(Locator locator) {
   this.locator = locator;
 }
 public void startElement(String uri, String localName, String qName, Attributes attrs)
     throws SAXException {
   if (qName.equals("order")) {
     System.out.println("here process element start");
   } else {
     String location = "";
     if (locator != null) {
       location = locator.getSystemId(); // XML-document name;
       location += " line " + locator.getLineNumber();
       location += ", column " + locator.getColumnNumber();
       location += ": ";
     }
     throw new SAXException(location + "Illegal element");
   }
 }
 public static void main(String[] args) throws Exception {
   SAXParserFactory factory = SAXParserFactory.newInstance();
   factory.setValidating(true);
   SAXParser parser = factory.newSAXParser();
   parser.parse("sample.xml", new SampleOfXmlLocator());
 }

}</source>


Источник — «http://jexp.ru/index.php?title=Java_Tutorial/XML/SAX&oldid=5116»