--- /dev/null
+// ContentHandler.java - handle main document content.
+// http://www.saxproject.org
+// Written by David Megginson
+// NO WARRANTY! This class is in the public domain.
+// $Id: ContentHandler.java,v 1.13 2004/04/26 17:50:49 dmegginson Exp $
+
+package org.xml.sax;
+
+
+/**
+ * Receive notification of the logical content of a document.
+ *
+ * <blockquote>
+ * <em>This module, both source code and documentation, is in the
+ * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
+ * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
+ * for further information.
+ * </blockquote>
+ *
+ * <p>This is the main interface that most SAX applications
+ * implement: if the application needs to be informed of basic parsing
+ * events, it implements this interface and registers an instance with
+ * the SAX parser using the {@link org.xml.sax.XMLReader#setContentHandler
+ * setContentHandler} method. The parser uses the instance to report
+ * basic document-related events like the start and end of elements
+ * and character data.</p>
+ *
+ * <p>The order of events in this interface is very important, and
+ * mirrors the order of information in the document itself. For
+ * example, all of an element's content (character data, processing
+ * instructions, and/or subelements) will appear, in order, between
+ * the startElement event and the corresponding endElement event.</p>
+ *
+ * <p>This interface is similar to the now-deprecated SAX 1.0
+ * DocumentHandler interface, but it adds support for Namespaces
+ * and for reporting skipped entities (in non-validating XML
+ * processors).</p>
+ *
+ * <p>Implementors should note that there is also a
+ * <code>ContentHandler</code> class in the <code>java.net</code>
+ * package; that means that it's probably a bad idea to do</p>
+ *
+ * <pre>import java.net.*;
+ * import org.xml.sax.*;
+ * </pre>
+ *
+ * <p>In fact, "import ...*" is usually a sign of sloppy programming
+ * anyway, so the user should consider this a feature rather than a
+ * bug.</p>
+ *
+ * @since SAX 2.0
+ * @author David Megginson
+ * @version 2.0.1+ (sax2r3pre1)
+ * @see org.xml.sax.XMLReader
+ * @see org.xml.sax.DTDHandler
+ * @see org.xml.sax.ErrorHandler
+ */
+public interface ContentHandler
+{
+
+ /**
+ * Receive an object for locating the origin of SAX document events.
+ *
+ * <p>SAX parsers are strongly encouraged (though not absolutely
+ * required) to supply a locator: if it does so, it must supply
+ * the locator to the application by invoking this method before
+ * invoking any of the other methods in the ContentHandler
+ * interface.</p>
+ *
+ * <p>The locator allows the application to determine the end
+ * position of any document-related event, even if the parser is
+ * not reporting an error. Typically, the application will
+ * use this information for reporting its own errors (such as
+ * character content that does not match an application's
+ * business rules). The information returned by the locator
+ * is probably not sufficient for use with a search engine.</p>
+ *
+ * <p>Note that the locator will return correct information only
+ * during the invocation SAX event callbacks after
+ * {@link #startDocument startDocument} returns and before
+ * {@link #endDocument endDocument} is called. The
+ * application should not attempt to use it at any other time.</p>
+ *
+ * @param locator an object that can return the location of
+ * any SAX document event
+ * @see org.xml.sax.Locator
+ */
+ public void setDocumentLocator (Locator locator);
+
+
+ /**
+ * Receive notification of the beginning of a document.
+ *
+ * <p>The SAX parser will invoke this method only once, before any
+ * other event callbacks (except for {@link #setDocumentLocator
+ * setDocumentLocator}).</p>
+ *
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ * @see #endDocument
+ */
+ public void startDocument ()
+ throws SAXException;
+
+
+ /**
+ * Receive notification of the end of a document.
+ *
+ * <p><strong>There is an apparent contradiction between the
+ * documentation for this method and the documentation for {@link
+ * org.xml.sax.ErrorHandler#fatalError}. Until this ambiguity is
+ * resolved in a future major release, clients should make no
+ * assumptions about whether endDocument() will or will not be
+ * invoked when the parser has reported a fatalError() or thrown
+ * an exception.</strong></p>
+ *
+ * <p>The SAX parser will invoke this method only once, and it will
+ * be the last method invoked during the parse. The parser shall
+ * not invoke this method until it has either abandoned parsing
+ * (because of an unrecoverable error) or reached the end of
+ * input.</p>
+ *
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ * @see #startDocument
+ */
+ public void endDocument()
+ throws SAXException;
+
+
+ /**
+ * Begin the scope of a prefix-URI Namespace mapping.
+ *
+ * <p>The information from this event is not necessary for
+ * normal Namespace processing: the SAX XML reader will
+ * automatically replace prefixes for element and attribute
+ * names when the <code>http://xml.org/sax/features/namespaces</code>
+ * feature is <var>true</var> (the default).</p>
+ *
+ * <p>There are cases, however, when applications need to
+ * use prefixes in character data or in attribute values,
+ * where they cannot safely be expanded automatically; the
+ * start/endPrefixMapping event supplies the information
+ * to the application to expand prefixes in those contexts
+ * itself, if necessary.</p>
+ *
+ * <p>Note that start/endPrefixMapping events are not
+ * guaranteed to be properly nested relative to each other:
+ * all startPrefixMapping events will occur immediately before the
+ * corresponding {@link #startElement startElement} event,
+ * and all {@link #endPrefixMapping endPrefixMapping}
+ * events will occur immediately after the corresponding
+ * {@link #endElement endElement} event,
+ * but their order is not otherwise
+ * guaranteed.</p>
+ *
+ * <p>There should never be start/endPrefixMapping events for the
+ * "xml" prefix, since it is predeclared and immutable.</p>
+ *
+ * @param prefix the Namespace prefix being declared.
+ * An empty string is used for the default element namespace,
+ * which has no prefix.
+ * @param uri the Namespace URI the prefix is mapped to
+ * @throws org.xml.sax.SAXException the client may throw
+ * an exception during processing
+ * @see #endPrefixMapping
+ * @see #startElement
+ */
+ public void startPrefixMapping (String prefix, String uri)
+ throws SAXException;
+
+
+ /**
+ * End the scope of a prefix-URI mapping.
+ *
+ * <p>See {@link #startPrefixMapping startPrefixMapping} for
+ * details. These events will always occur immediately after the
+ * corresponding {@link #endElement endElement} event, but the order of
+ * {@link #endPrefixMapping endPrefixMapping} events is not otherwise
+ * guaranteed.</p>
+ *
+ * @param prefix the prefix that was being mapped.
+ * This is the empty string when a default mapping scope ends.
+ * @throws org.xml.sax.SAXException the client may throw
+ * an exception during processing
+ * @see #startPrefixMapping
+ * @see #endElement
+ */
+ public void endPrefixMapping (String prefix)
+ throws SAXException;
+
+
+ /**
+ * Receive notification of the beginning of an element.
+ *
+ * <p>The Parser will invoke this method at the beginning of every
+ * element in the XML document; there will be a corresponding
+ * {@link #endElement endElement} event for every startElement event
+ * (even when the element is empty). All of the element's content will be
+ * reported, in order, before the corresponding endElement
+ * event.</p>
+ *
+ * <p>This event allows up to three name components for each
+ * element:</p>
+ *
+ * <ol>
+ * <li>the Namespace URI;</li>
+ * <li>the local name; and</li>
+ * <li>the qualified (prefixed) name.</li>
+ * </ol>
+ *
+ * <p>Any or all of these may be provided, depending on the
+ * values of the <var>http://xml.org/sax/features/namespaces</var>
+ * and the <var>http://xml.org/sax/features/namespace-prefixes</var>
+ * properties:</p>
+ *
+ * <ul>
+ * <li>the Namespace URI and local name are required when
+ * the namespaces property is <var>true</var> (the default), and are
+ * optional when the namespaces property is <var>false</var> (if one is
+ * specified, both must be);</li>
+ * <li>the qualified name is required when the namespace-prefixes property
+ * is <var>true</var>, and is optional when the namespace-prefixes property
+ * is <var>false</var> (the default).</li>
+ * </ul>
+ *
+ * <p>Note that the attribute list provided will contain only
+ * attributes with explicit values (specified or defaulted):
+ * #IMPLIED attributes will be omitted. The attribute list
+ * will contain attributes used for Namespace declarations
+ * (xmlns* attributes) only if the
+ * <code>http://xml.org/sax/features/namespace-prefixes</code>
+ * property is true (it is false by default, and support for a
+ * true value is optional).</p>
+ *
+ * <p>Like {@link #characters characters()}, attribute values may have
+ * characters that need more than one <code>char</code> value. </p>
+ *
+ * @param uri the Namespace URI, or the empty string if the
+ * element has no Namespace URI or if Namespace
+ * processing is not being performed
+ * @param localName the local name (without prefix), or the
+ * empty string if Namespace processing is not being
+ * performed
+ * @param qName the qualified name (with prefix), or the
+ * empty string if qualified names are not available
+ * @param atts the attributes attached to the element. If
+ * there are no attributes, it shall be an empty
+ * Attributes object. The value of this object after
+ * startElement returns is undefined
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ * @see #endElement
+ * @see org.xml.sax.Attributes
+ * @see org.xml.sax.helpers.AttributesImpl
+ */
+ public void startElement (String uri, String localName,
+ String qName, Attributes atts)
+ throws SAXException;
+
+
+ /**
+ * Receive notification of the end of an element.
+ *
+ * <p>The SAX parser will invoke this method at the end of every
+ * element in the XML document; there will be a corresponding
+ * {@link #startElement startElement} event for every endElement
+ * event (even when the element is empty).</p>
+ *
+ * <p>For information on the names, see startElement.</p>
+ *
+ * @param uri the Namespace URI, or the empty string if the
+ * element has no Namespace URI or if Namespace
+ * processing is not being performed
+ * @param localName the local name (without prefix), or the
+ * empty string if Namespace processing is not being
+ * performed
+ * @param qName the qualified XML name (with prefix), or the
+ * empty string if qualified names are not available
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ */
+ public void endElement (String uri, String localName,
+ String qName)
+ throws SAXException;
+
+
+ /**
+ * Receive notification of character data.
+ *
+ * <p>The Parser will call this method to report each chunk of
+ * character data. SAX parsers may return all contiguous character
+ * data in a single chunk, or they may split it into several
+ * chunks; however, all of the characters in any single event
+ * must come from the same external entity so that the Locator
+ * provides useful information.</p>
+ *
+ * <p>The application must not attempt to read from the array
+ * outside of the specified range.</p>
+ *
+ * <p>Individual characters may consist of more than one Java
+ * <code>char</code> value. There are two important cases where this
+ * happens, because characters can't be represented in just sixteen bits.
+ * In one case, characters are represented in a <em>Surrogate Pair</em>,
+ * using two special Unicode values. Such characters are in the so-called
+ * "Astral Planes", with a code point above U+FFFF. A second case involves
+ * composite characters, such as a base character combining with one or
+ * more accent characters. </p>
+ *
+ * <p> Your code should not assume that algorithms using
+ * <code>char</code>-at-a-time idioms will be working in character
+ * units; in some cases they will split characters. This is relevant
+ * wherever XML permits arbitrary characters, such as attribute values,
+ * processing instruction data, and comments as well as in data reported
+ * from this method. It's also generally relevant whenever Java code
+ * manipulates internationalized text; the issue isn't unique to XML.</p>
+ *
+ * <p>Note that some parsers will report whitespace in element
+ * content using the {@link #ignorableWhitespace ignorableWhitespace}
+ * method rather than this one (validating parsers <em>must</em>
+ * do so).</p>
+ *
+ * @param ch the characters from the XML document
+ * @param start the start position in the array
+ * @param length the number of characters to read from the array
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ * @see #ignorableWhitespace
+ * @see org.xml.sax.Locator
+ */
+ public void characters (char ch[], int start, int length)
+ throws SAXException;
+
+
+ /**
+ * Receive notification of ignorable whitespace in element content.
+ *
+ * <p>Validating Parsers must use this method to report each chunk
+ * of whitespace in element content (see the W3C XML 1.0
+ * recommendation, section 2.10): non-validating parsers may also
+ * use this method if they are capable of parsing and using
+ * content models.</p>
+ *
+ * <p>SAX parsers may return all contiguous whitespace in a single
+ * chunk, or they may split it into several chunks; however, all of
+ * the characters in any single event must come from the same
+ * external entity, so that the Locator provides useful
+ * information.</p>
+ *
+ * <p>The application must not attempt to read from the array
+ * outside of the specified range.</p>
+ *
+ * @param ch the characters from the XML document
+ * @param start the start position in the array
+ * @param length the number of characters to read from the array
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ * @see #characters
+ */
+ public void ignorableWhitespace (char ch[], int start, int length)
+ throws SAXException;
+
+
+ /**
+ * Receive notification of a processing instruction.
+ *
+ * <p>The Parser will invoke this method once for each processing
+ * instruction found: note that processing instructions may occur
+ * before or after the main document element.</p>
+ *
+ * <p>A SAX parser must never report an XML declaration (XML 1.0,
+ * section 2.8) or a text declaration (XML 1.0, section 4.3.1)
+ * using this method.</p>
+ *
+ * <p>Like {@link #characters characters()}, processing instruction
+ * data may have characters that need more than one <code>char</code>
+ * value. </p>
+ *
+ * @param target the processing instruction target
+ * @param data the processing instruction data, or null if
+ * none was supplied. The data does not include any
+ * whitespace separating it from the target
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ */
+ public void processingInstruction (String target, String data)
+ throws SAXException;
+
+
+ /**
+ * Receive notification of a skipped entity.
+ * This is not called for entity references within markup constructs
+ * such as element start tags or markup declarations. (The XML
+ * recommendation requires reporting skipped external entities.
+ * SAX also reports internal entity expansion/non-expansion, except
+ * within markup constructs.)
+ *
+ * <p>The Parser will invoke this method each time the entity is
+ * skipped. Non-validating processors may skip entities if they
+ * have not seen the declarations (because, for example, the
+ * entity was declared in an external DTD subset). All processors
+ * may skip external entities, depending on the values of the
+ * <code>http://xml.org/sax/features/external-general-entities</code>
+ * and the
+ * <code>http://xml.org/sax/features/external-parameter-entities</code>
+ * properties.</p>
+ *
+ * @param name the name of the skipped entity. If it is a
+ * parameter entity, the name will begin with '%', and if
+ * it is the external DTD subset, it will be the string
+ * "[dtd]"
+ * @throws org.xml.sax.SAXException any SAX exception, possibly
+ * wrapping another exception
+ */
+ public void skippedEntity (String name)
+ throws SAXException;
+}
+
+// end of ContentHandler.java
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