Class Parser
- java.lang.Object
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- javax.swing.text.html.parser.Parser
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- 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   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
strictis 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:
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DTD,TagElement,SimpleAttributeSet
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Field Summary
Fields Modifier and Type Field and Description protected DTDdtdprotected booleanstrictThis 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
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method and Description protected voidendTag(boolean omitted)Handle an end tag.protected voiderror(String err)protected voiderror(String err, String arg1)protected voiderror(String err, String arg1, String arg2)protected voiderror(String err, String arg1, String arg2, String arg3)Invoke the error handler.protected voidflushAttributes()protected SimpleAttributeSetgetAttributes()protected intgetCurrentLine()protected intgetCurrentPos()protected voidhandleComment(char[] text)Called when an HTML comment is encountered.protected voidhandleEmptyTag(TagElement tag)Called when an empty tag is encountered.protected voidhandleEndTag(TagElement tag)Called when an end tag is encountered.protected voidhandleEOFInComment()protected voidhandleError(int ln, String msg)An error has occurred.protected voidhandleStartTag(TagElement tag)Called when a start tag is encountered.protected voidhandleText(char[] text)Called when PCDATA is encountered.protected voidhandleTitle(char[] text)Called when an HTML title tag is encountered.protected TagElementmakeTag(Element elem)protected TagElementmakeTag(Element elem, boolean fictional)Makes a TagElement.protected voidmarkFirstTime(Element elem)Marks the first time a tag has been seen in a documentvoidparse(Reader in)Parse an HTML stream, given a DTD.StringparseDTDMarkup()Parses th Document Declaration Type markup declaration.protected booleanparseMarkupDeclarations(StringBuffer strBuff)Parse markup declarations.protected voidstartTag(TagElement tag)Handle a start tag.
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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.
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Constructor Detail
Parser
public Parser(DTD dtd)
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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:
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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)
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:
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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:
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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:
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IOException
parse
public void parse(Reader in) throws IOException
Parse an HTML stream, given a DTD.- Throws:
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IOException
getCurrentPos
protected int getCurrentPos()
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Submit a bug or feature
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