public class

Parser

extends Object
implements DTDConstants
java.lang.Object
   ↳ javax.swing.text.html.parser.Parser
Known Direct Subclasses

Class Overview

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

Summary

[Expand]
Inherited Constants
From interface javax.swing.text.html.parser.DTDConstants
Fields
protected DTD dtd
protected boolean strict This flag determines whether or not the Parser will be strict in enforcing SGML compatibility.
Public Constructors
Parser(DTD dtd)
Public Methods
synchronized void parse(Reader in)
Parse an HTML stream, given a DTD.
String parseDTDMarkup()
Parses th Document Declaration Type markup declaration.
Protected Methods
void endTag(boolean omitted)
Handle an end tag.
void error(String err)
void error(String err, String arg1, String arg2)
void error(String err, String arg1, String arg2, String arg3)
Invoke the error handler.
void error(String err, String arg1)
void flushAttributes()
SimpleAttributeSet getAttributes()
int getCurrentLine()
int getCurrentPos()
void handleComment(char[] text)
Called when an HTML comment is encountered.
void handleEOFInComment()
void handleEmptyTag(TagElement tag)
Called when an empty tag is encountered.
void handleEndTag(TagElement tag)
Called when an end tag is encountered.
void handleError(int ln, String msg)
An error has occurred.
void handleStartTag(TagElement tag)
Called when a start tag is encountered.
void handleText(char[] text)
Called when PCDATA is encountered.
void handleTitle(char[] text)
Called when an HTML title tag is encountered.
TagElement makeTag(Element elem, boolean fictional)
Makes a TagElement.
TagElement makeTag(Element elem)
void markFirstTime(Element elem)
Marks the first time a tag has been seen in a document
boolean parseMarkupDeclarations(StringBuffer strBuff)
Parse markup declarations.
void startTag(TagElement tag)
Handle a start tag.
[Expand]
Inherited Methods
From class java.lang.Object

Fields

protected DTD dtd

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.

Public Constructors

public Parser (DTD dtd)

Public Methods

public synchronized void parse (Reader in)

Parse an HTML stream, given a DTD.

Throws
IOException

public String parseDTDMarkup ()

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

Throws
IOException

Protected Methods

protected void endTag (boolean omitted)

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

protected void error (String err)

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 error (String err, String arg1)

protected void flushAttributes ()

protected SimpleAttributeSet getAttributes ()

protected int getCurrentLine ()

Returns
  • the line number of the line currently being parsed

protected int getCurrentPos ()

protected void handleComment (char[] text)

Called when an HTML comment is encountered.

protected void handleEOFInComment ()

protected void handleEmptyTag (TagElement tag)

Called when an empty tag is encountered.

Throws
ChangedCharSetException

protected void handleEndTag (TagElement tag)

Called when an end tag is encountered.

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, boolean fictional)

Makes a TagElement.

protected TagElement makeTag (Element elem)

protected void markFirstTime (Element elem)

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

protected boolean parseMarkupDeclarations (StringBuffer strBuff)

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

Throws
IOException

protected void startTag (TagElement tag)

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

Throws
ChangedCharSetException