- * This module, both source code and documentation, is in the - * Public Domain, and comes with NO WARRANTY. - * See http://www.saxproject.org - * for further information. - *- * - *
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.
- * - *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.
- * - *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).
- * - *Implementors should note that there is also a
- * ContentHandler class in the java.net
- * package; that means that it's probably a bad idea to do
import java.net.*; - * import org.xml.sax.*; - *- * - *
In fact, "import ...*" is usually a sign of sloppy programming - * anyway, so the user should consider this a feature rather than a - * bug.
- * - * @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. - * - *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.
- * - *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.
- * - *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.
- * - * @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. - * - *The SAX parser will invoke this method only once, before any - * other event callbacks (except for {@link #setDocumentLocator - * setDocumentLocator}).
- * - * @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. - * - *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.
- * - *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.
- * - * @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. - * - *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 http://xml.org/sax/features/namespaces
- * feature is true (the default).
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.
- * - *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.
- * - *There should never be start/endPrefixMapping events for the - * "xml" prefix, since it is predeclared and immutable.
- * - * @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. - * - *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.
- * - * @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. - * - *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.
- * - *This event allows up to three name components for each - * element:
- * - *Any or all of these may be provided, depending on the - * values of the http://xml.org/sax/features/namespaces - * and the http://xml.org/sax/features/namespace-prefixes - * properties:
- * - *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
- * http://xml.org/sax/features/namespace-prefixes
- * property is true (it is false by default, and support for a
- * true value is optional).
Like {@link #characters characters()}, attribute values may have
- * characters that need more than one char value.
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).
- * - *For information on the names, see startElement.
- * - * @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. - * - *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.
- * - *The application must not attempt to read from the array - * outside of the specified range.
- * - *Individual characters may consist of more than one Java
- * char 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 Surrogate Pair,
- * 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.
Your code should not assume that algorithms using
- * char-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.
Note that some parsers will report whitespace in element - * content using the {@link #ignorableWhitespace ignorableWhitespace} - * method rather than this one (validating parsers must - * do so).
- * - * @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. - * - *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.
- * - *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.
- * - *The application must not attempt to read from the array - * outside of the specified range.
- * - * @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. - * - *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.
- * - *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.
- * - *Like {@link #characters characters()}, processing instruction
- * data may have characters that need more than one char
- * value.
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
- * http://xml.org/sax/features/external-general-entities
- * and the
- * http://xml.org/sax/features/external-parameter-entities
- * properties.