javax.swing.text.html.parser
Class Parser

java.lang.Object
  javax.swing.text.html.parser.Parser

All Implemented Interfaces:

DTDConstants

Direct Known Subclasses:

DocumentParser

public class Parser
extends Object
implements DTDConstants

A simple DTD-driven HTML parser. The parser reads an HTML file from an InputStream and calls various methods (which should be overridden in a subclass) when tags and data are encountered.

Unfortunately there are many badly implemented HTML parsers out there, and as a result there are many badly formatted HTML files. This parser attempts to parse most HTML files. This means that the implementation sometimes deviates from the SGML specification in favor of HTML.

The parser treats \r and \r\n as \n. Newlines after starttags and before end tags are ignored just as specified in the SGML/HTML specification.

The html spec does not specify how spaces are to be coalesced very well. Specifically, the following scenarios are not discussed (note that a space should be used here, but I am using &nbsp to force the space to be displayed):

'<b>blah <i> <strike> foo' which can be treated as: '<b>blah <i><strike>foo'

as well as: '<p><a href="xx"> <em>Using</em></a></p>' which appears to be treated as: '<p><a href="xx"><em>Using</em></a></p>'

If strict is false, when a tag that breaks flow, (TagElement.breaksFlows) or trailing whitespace is encountered, all whitespace will be ignored until a non whitespace character is encountered. This appears to give behavior closer to the popular browsers.

See Also:

DTD, TagElement, SimpleAttributeSet

Field Summary

protected DTD	dtd
protected boolean	strict This flag determines whether or not the Parser will be strict in enforcing SGML compatibility.

Fields inherited from interface javax.swing.text.html.parser.DTDConstants

ANY, CDATA, CONREF, CURRENT, DEFAULT, EMPTY, ENDTAG, ENTITIES, ENTITY, FIXED, GENERAL, ID, IDREF, IDREFS, IMPLIED, MD, MODEL, MS, NAME, NAMES, NMTOKEN, NMTOKENS, NOTATION, NUMBER, NUMBERS, NUTOKEN, NUTOKENS, PARAMETER, PI, PUBLIC, RCDATA, REQUIRED, SDATA, STARTTAG, SYSTEM

Constructor Summary

Parser(DTD dtd)

Method Summary

protected void	endTag(boolean omitted) Handle an end tag.
protected void	error(String err)
protected void	error(String err, String arg1)
protected void	error(String err, String arg1, String arg2)
protected void	error(String err, String arg1, String arg2, String arg3) Invoke the error handler.
protected void	flushAttributes()
protected SimpleAttributeSet	getAttributes()
protected int	getCurrentLine()
protected int	getCurrentPos()
protected void	handleComment(char[] text) Called when an HTML comment is encountered.
protected void	handleEmptyTag(TagElement tag) Called when an empty tag is encountered.
protected void	handleEndTag(TagElement tag) Called when an end tag is encountered.
protected void	handleEOFInComment()
protected void	handleError(int ln, String msg) An error has occurred.
protected void	handleStartTag(TagElement tag) Called when a start tag is encountered.
protected void	handleText(char[] text) Called when PCDATA is encountered.
protected void	handleTitle(char[] text) Called when an HTML title tag is encountered.
protected TagElement	makeTag(Element elem)
protected TagElement	makeTag(Element elem, boolean fictional) Makes a TagElement.
protected void	markFirstTime(Element elem) Marks the first time a tag has been seen in a document
void	parse(Reader in) Parse an HTML stream, given a DTD.
String	parseDTDMarkup() Parses th Document Declaration Type markup declaration.
protected boolean	parseMarkupDeclarations(StringBuffer strBuff) Parse markup declarations.
protected void	startTag(TagElement tag) Handle a start tag.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

dtd

protected DTD dtd

strict

protected boolean strict

This flag determines whether or not the Parser will be strict in enforcing SGML compatibility. If false, it will be lenient with certain common classes of erroneous HTML constructs. Strict or not, in either case an error will be recorded.

Constructor Detail

Parser

public Parser(DTD dtd)

Method Detail

getCurrentLine

protected int getCurrentLine()

Returns:

the line number of the line currently being parsed

makeTag

protected TagElement makeTag(Element elem,
                             boolean fictional)

Makes a TagElement.

makeTag

protected TagElement makeTag(Element elem)

getAttributes

protected SimpleAttributeSet getAttributes()

flushAttributes

protected void flushAttributes()

handleText

protected void handleText(char[] text)

Called when PCDATA is encountered.

handleTitle

protected void handleTitle(char[] text)

Called when an HTML title tag is encountered.

handleComment

protected void handleComment(char[] text)

Called when an HTML comment is encountered.

handleEOFInComment

protected void handleEOFInComment()

handleEmptyTag

protected void handleEmptyTag(TagElement tag)
                       throws ChangedCharSetException

Called when an empty tag is encountered.

Throws:

ChangedCharSetException

handleStartTag

protected void handleStartTag(TagElement tag)

Called when a start tag is encountered.

handleEndTag

protected void handleEndTag(TagElement tag)

Called when an end tag is encountered.

handleError

protected void handleError(int ln,
                           String msg)

An error has occurred.

error

protected void error(String err,
                     String arg1,
                     String arg2,
                     String arg3)

Invoke the error handler.

error

protected void error(String err,
                     String arg1,
                     String arg2)

error

protected void error(String err,
                     String arg1)

error

protected void error(String err)

startTag

protected void startTag(TagElement tag)
                 throws ChangedCharSetException

Handle a start tag. The new tag is pushed onto the tag stack. The attribute list is checked for required attributes.

Throws:

ChangedCharSetException

endTag

protected void endTag(boolean omitted)

Handle an end tag. The end tag is popped from the tag stack.

markFirstTime

protected void markFirstTime(Element elem)

Marks the first time a tag has been seen in a document

parseDTDMarkup

public String parseDTDMarkup()
                      throws IOException

Parses th Document Declaration Type markup declaration. Currently ignores it.

Throws:

IOException

parseMarkupDeclarations

protected boolean parseMarkupDeclarations(StringBuffer strBuff)
                                   throws IOException

Parse markup declarations. Currently only handles the Document Type Declaration markup. Returns true if it is a markup declaration false otherwise.

Throws:

IOException

parse

public void parse(Reader in)
           throws IOException

Parse an HTML stream, given a DTD.

Throws:

IOException

getCurrentPos

protected int getCurrentPos()