Java tutorial
/*-- Copyright (C) 2001 Brett McLaughlin. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions, and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions, and the disclaimer that follows these conditions in the documentation and/or other materials provided with the distribution. 3. The name "Java and XML" must not be used to endorse or promote products derived from this software without prior written permission. For written permission, please contact brett@newInstance.com. In addition, we request (but do not require) that you include in the end-user documentation provided with the redistribution and/or in the software itself an acknowledgement equivalent to the following: "This product includes software developed for the 'Java and XML' book, by Brett McLaughlin (O'Reilly & Associates)." THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE JDOM AUTHORS OR THE PROJECT CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ import java.io.IOException; import java.util.HashMap; import java.util.Iterator; import java.util.Map; 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; import org.xml.sax.helpers.XMLReaderFactory; // This is an XML book - no need for explicit Swing imports import java.awt.*; import javax.swing.*; import javax.swing.tree.*; /** * <b><code>SAXTreeValidator</code></b> uses Swing to graphically * display an XML document, and performs validation. */ public class SAXTreeValidator extends JFrame { /** Default parser to use */ private String vendorParserClass = "org.apache.xerces.parsers.SAXParser"; /** The base tree to render */ private JTree jTree; /** Tree model to use */ DefaultTreeModel defaultTreeModel; /** * <p> This initializes the needed Swing settings. </p> */ public SAXTreeValidator() { // Handle Swing setup super("SAX Tree Validator"); setSize(600, 450); } /** * <p> This will construct the tree using Swing. </p> * * @param filename <code>String</code> path to XML document. */ public void init(String xmlURI) throws IOException, SAXException { DefaultMutableTreeNode base = new DefaultMutableTreeNode("XML Document: " + xmlURI); // Build the tree model defaultTreeModel = new DefaultTreeModel(base); jTree = new JTree(defaultTreeModel); // Construct the tree hierarchy buildTree(defaultTreeModel, base, xmlURI); // Display the results getContentPane().add(new JScrollPane(jTree), BorderLayout.CENTER); } /** * <p>This handles building the Swing UI tree.</p> * * @param treeModel Swing component to build upon. * @param base tree node to build on. * @param xmlURI URI to build XML document from. * @throws <code>IOException</code> - when reading the XML URI fails. * @throws <code>SAXException</code> - when errors in parsing occur. */ public void buildTree(DefaultTreeModel treeModel, DefaultMutableTreeNode base, String xmlURI) throws IOException, SAXException { // Create instances needed for parsing XMLReader reader = XMLReaderFactory.createXMLReader(vendorParserClass); ContentHandler jTreeContentHandler = new JValidatorContentHandler(treeModel, base); ErrorHandler jTreeErrorHandler = new JValidatorErrorHandler(); // Register content handler reader.setContentHandler(jTreeContentHandler); // Register error handler reader.setErrorHandler(jTreeErrorHandler); // Turn on validation reader.setFeature("http://xml.org/sax/features/validation", true); reader.setFeature("http://apache.org/xml/features/validation/schema-full-checking", true); // Parse InputSource inputSource = new InputSource(xmlURI); reader.parse(inputSource); } /** * <p> Static entry point for running the viewer. </p> */ public static void main(String[] args) { try { if (args.length != 1) { System.out.println("Usage: java SAXTreeViewer " + "[XML Document URI]"); System.exit(0); } SAXTreeValidator viewer = new SAXTreeValidator(); viewer.init(args[0]); viewer.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } } /** * <b><code>JValidatorContentHandler</code></b> implements the SAX * <code>ContentHandler</code> interface and defines callback * behavior for the SAX callbacks associated with an XML * document's content, bulding up JTree nodes. */ class JValidatorContentHandler implements ContentHandler { /** Hold onto the locator for location information */ private Locator locator; /** Store URI to prefix mappings */ private Map namespaceMappings; /** Tree Model to add nodes to */ private DefaultTreeModel treeModel; /** Current node to add sub-nodes to */ private DefaultMutableTreeNode current; /** * <p> Set up for working with the JTree. </p> * * @param treeModel tree to add nodes to. * @param base node to start adding sub-nodes to. */ public JValidatorContentHandler(DefaultTreeModel treeModel, DefaultMutableTreeNode base) { this.treeModel = treeModel; this.current = base; this.namespaceMappings = new HashMap(); } /** * <p> * Provide reference to <code>Locator</code> which provides * information about where in a document callbacks occur. * </p> * * @param locator <code>Locator</code> object tied to callback * process */ public void setDocumentLocator(Locator locator) { // Save this for later use this.locator = locator; } /** * <p> * This indicates the start of a Document parse-this precedes * all callbacks in all SAX Handlers with the sole exception * of <code>{@link #setDocumentLocator}</code>. * </p> * * @throws <code>SAXException</code> when things go wrong */ public void startDocument() throws SAXException { // No visual events occur here } /** * <p> * This indicates the end of a Document parse-this occurs after * all callbacks in all SAX Handlers.</code>. * </p> * * @throws <code>SAXException</code> when things go wrong */ public void endDocument() throws SAXException { // No visual events occur here } /** * <p> * This indicates that a processing instruction (other than * the XML declaration) has been encountered. * </p> * * @param target <code>String</code> target of PI * @param data <code>String</code containing all data sent to the PI. * This typically looks like one or more attribute value * pairs. * @throws <code>SAXException</code> when things go wrong */ public void processingInstruction(String target, String data) throws SAXException { DefaultMutableTreeNode pi = new DefaultMutableTreeNode( "PI (target = '" + target + "', data = '" + data + "')"); current.add(pi); } /** * <p> * This indicates the beginning of an XML Namespace prefix * mapping. Although this typically occurs within the root element * of an XML document, it can occur at any point within the * document. Note that a prefix mapping on an element triggers * this callback <i>before</i> the callback for the actual element * itself (<code>{@link #startElement}</code>) occurs. * </p> * * @param prefix <code>String</code> prefix used for the namespace * being reported * @param uri <code>String</code> URI for the namespace * being reported * @throws <code>SAXException</code> when things go wrong */ public void startPrefixMapping(String prefix, String uri) { // No visual events occur here. namespaceMappings.put(uri, prefix); } /** * <p> * This indicates the end of a prefix mapping, when the namespace * reported in a <code>{@link #startPrefixMapping}</code> callback * is no longer available. * </p> * * @param prefix <code>String</code> of namespace being reported * @throws <code>SAXException</code> when things go wrong */ public void endPrefixMapping(String prefix) { // No visual events occur here. for (Iterator i = namespaceMappings.keySet().iterator(); i.hasNext();) { String uri = (String) i.next(); String thisPrefix = (String) namespaceMappings.get(uri); if (prefix.equals(thisPrefix)) { namespaceMappings.remove(uri); break; } } } /** * <p> * This reports the occurrence of an actual element. It includes * the element's attributes, with the exception of XML vocabulary * specific attributes, such as * <code>xmlns:[namespace prefix]</code> and * <code>xsi:schemaLocation</code>. * </p> * * @param namespaceURI <code>String</code> namespace URI this element * is associated with, or an empty <code>String</code> * @param localName <code>String</code> name of element (with no * namespace prefix, if one is present) * @param qName <code>String</code> XML 1.0 version of element name: * [namespace prefix]:[localName] * @param atts <code>Attributes</code> list for this element * @throws <code>SAXException</code> when things go wrong */ public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException { DefaultMutableTreeNode element = new DefaultMutableTreeNode("Element: " + localName); current.add(element); current = element; // Determine namespace if (namespaceURI.length() > 0) { String prefix = (String) namespaceMappings.get(namespaceURI); if (prefix.equals("")) { prefix = "[None]"; } DefaultMutableTreeNode namespace = new DefaultMutableTreeNode( "Namespace: prefix = '" + prefix + "', URI = '" + namespaceURI + "'"); current.add(namespace); } // Process attributes for (int i = 0; i < atts.getLength(); i++) { DefaultMutableTreeNode attribute = new DefaultMutableTreeNode( "Attribute (name = '" + atts.getLocalName(i) + "', value = '" + atts.getValue(i) + "')"); String attURI = atts.getURI(i); if (attURI.length() > 0) { String attPrefix = (String) namespaceMappings.get(namespaceURI); if (attPrefix.equals("")) { attPrefix = "[None]"; } DefaultMutableTreeNode attNamespace = new DefaultMutableTreeNode( "Namespace: prefix = '" + attPrefix + "', URI = '" + attURI + "'"); attribute.add(attNamespace); } current.add(attribute); } } /** * <p> * Indicates the end of an element * (<code></[element name]></code>) is reached. Note that * the parser does not distinguish between empty * elements and non-empty elements, so this occurs uniformly. * </p> * * @param namespaceURI <code>String</code> URI of namespace this * element is associated with * @param localName <code>String</code> name of element without prefix * @param qName <code>String</code> name of element in XML 1.0 form * @throws <code>SAXException</code> when things go wrong */ public void endElement(String namespaceURI, String localName, String qName) throws SAXException { // Walk back up the tree current = (DefaultMutableTreeNode) current.getParent(); } /** * <p> * This reports character data (within an element). * </p> * * @param ch <code>char[]</code> character array with character data * @param start <code>int</code> index in array where data starts. * @param length <code>int</code> index in array where data ends. * @throws <code>SAXException</code> when things go wrong */ public void characters(char[] ch, int start, int length) throws SAXException { String s = new String(ch, start, length); DefaultMutableTreeNode data = new DefaultMutableTreeNode("Character Data: '" + s + "'"); current.add(data); } /** * <p> * This reports whitespace that can be ignored in the * originating document. This is typically invoked only when * validation is ocurring in the parsing process. * </p> * * @param ch <code>char[]</code> character array with character data * @param start <code>int</code> index in array where data starts. * @param end <code>int</code> index in array where data ends. * @throws <code>SAXException</code> when things go wrong */ public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException { // This is ignorable, so don't display it } /** * <p> * This reports an entity that is skipped by the parser. This * should only occur for non-validating parsers, and then is still * implementation-dependent behavior. * </p> * * @param name <code>String</code> name of entity being skipped * @throws <code>SAXException</code> when things go wrong */ public void skippedEntity(String name) throws SAXException { DefaultMutableTreeNode skipped = new DefaultMutableTreeNode("Skipped Entity: '" + name + "'"); current.add(skipped); } } /** * <b><code>JValidatorErrorHandler</code></b> implements the SAX * <code>ErrorHandler</code> interface and defines callback * behavior for the SAX callbacks associated with an XML * document's warnings and errors. */ class JValidatorErrorHandler implements ErrorHandler { /** * <p> * This will report a warning that has occurred; this indicates * that while no XML rules were "broken", something appears * to be incorrect or missing. * </p> * * @param exception <code>SAXParseException</code> that occurred. * @throws <code>SAXException</code> when things go wrong */ public void warning(SAXParseException exception) throws SAXException { System.out.println("**Parsing Warning**\n" + " Line: " + exception.getLineNumber() + "\n" + " URI: " + exception.getSystemId() + "\n" + " Message: " + exception.getMessage()); throw new SAXException("Warning encountered"); } /** * <p> * This will report an error that has occurred; this indicates * that a rule was broken, typically in validation, but that * parsing can reasonably continue. * </p> * * @param exception <code>SAXParseException</code> that occurred. * @throws <code>SAXException</code> when things go wrong */ public void error(SAXParseException exception) throws SAXException { System.out.println("**Parsing Error**\n" + " Line: " + exception.getLineNumber() + "\n" + " URI: " + exception.getSystemId() + "\n" + " Message: " + exception.getMessage()); throw new SAXException("Error encountered"); } /** * <p> * This will report a fatal error that has occurred; this indicates * that a rule has been broken that makes continued parsing either * impossible or an almost certain waste of time. * </p> * * @param exception <code>SAXParseException</code> that occurred. * @throws <code>SAXException</code> when things go wrong */ public void fatalError(SAXParseException exception) throws SAXException { System.out.println("**Parsing Fatal Error**\n" + " Line: " + exception.getLineNumber() + "\n" + " URI: " + exception.getSystemId() + "\n" + " Message: " + exception.getMessage()); throw new SAXException("Fatal Error encountered"); } } // Demo file: book.xml /* <?xml version="1.0"?> <!DOCTYPE book SYSTEM "DTD/JavaXML.dtd"> <!-- Java and XML Contents --> <book xmlns="http://www.oreilly.com/javaxml2" xmlns:ora="http://www.oreilly.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.oreilly.com/javaxml2 XSD/contents.xsd http://www.oreilly.com XSD/contents-ora.xsd"> <title ora:series="Java">Java and XML</title> <!-- Chapter List --> <contents> <chapter title="Introduction" number="1"> <topic name="XML Matters"/> <topic name="What's Important"/> <topic name="The Essentials"/> <topic name="What's Next?"/> </chapter> <chapter title="Nuts and Bolts" number="2"> <topic name="The Basics"/> <topic name="Constraints"/> <topic name="Transformations"/> <topic name="And More..."/> <topic name="What's Next?"/> </chapter> <chapter title="SAX" number="3"> <topic name="Getting Prepared"/> <topic name="SAX Readers"/> <topic name="Content Handlers"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="Advanced SAX" number="4"> <topic name="Properties and Features"/> <topic name="More Handlers"/> <topic name="Filters and Writers"/> <topic name="Even More Handlers"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="DOM" number="5"> <topic name="The Document Object Model"/> <topic name="Serialization"/> <topic name="Mutability"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="Advanced DOM" number="6"> <topic name="DOM and Mutation"/> <topic name="Namespaces and DOM Level 2"/> <topic name="DOM and HTML"/> <topic name="DOM Level 3"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="JDOM" number="7"> <topic name="The Basics"/> <topic name="PropsToXML"/> <topic name="XMLProperties"/> <topic name="Is JDOM a Standard?"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="Advanced JDOM" number="8"> <topic name="The Whole Ball of Wax"/> <topic name="JDOM and Factories"/> <topic name="Wrappers and Decorators"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="JAXP" number="9"> <topic name="API or Abstraction?"/> <topic name="JAXP 1.0"/> <topic name="JAXP 1.1"/> <topic name="Gotcha!"/> <topic name="What's Next?"/> </chapter> <chapter title="Web Publishing Frameworks" number="10"> <topic name="Selecting a Framework"/> <topic name="Installation"/> <topic name="Using a Publishing Framework"/> <topic name="XSP"/> <topic name="Cocoon 2.0 and Beyond"/> <topic name="What's Next?"/> </chapter> <chapter title="XML-RPC" number="11"> <topic name="RPC Versus RMI"/> <topic name="Saying Hello"/> <topic name="The Real World"/> <topic name="What's Next?"/> </chapter> <chapter title="SOAP" number="12"> <topic name="Starting Out"/> <topic name="Setting Up"/> <topic name="Getting Dirty"/> <topic name="Going Further"/> <topic name="What's Next?"/> </chapter> <chapter title="Web Services" number="13"> <topic name="Web Services"/> <topic name="UDDI"/> <topic name="WSDL"/> <topic name="Putting It All Together"/> <topic name="What's Next?"/> </chapter> <chapter title="Content Syndication" number="14"> <topic name="The Foobar Public Library"/> <topic name="mytechbooks.comI"/> <topic name="Push Versus Pull"/> <topic name="What's Next?"/> </chapter> <chapter title="XML Data Binding" number="15"> <topic name="First Principles"/> <topic name="Castor"/> <topic name="Zeus"/> <topic name="JAXB"/> <topic name="What's Next?"/> </chapter> <chapter title="Looking Forward" number="16"> <topic name="XLink"/> <topic name="XPointer"/> <topic name="XML Schema Bindings"/> <topic name="And the Rest..."/> <topic name="What's Next?"/> </chapter> </contents> <ora:copyright>&OReillyCopyright;</ora:copyright> </book> */