Package org.apache.tika.parser

Class DelegatingParser

java.lang.Object

org.apache.tika.parser.DelegatingParser

All Implemented Interfaces:

Serializable, Parser

Direct Known Subclasses:

CryptoParser, LanguageDetectingParser

public class DelegatingParser
extends Object
implements Parser

Base class for parser implementations that want to delegate parts of the task of parsing an input document to another parser. The delegate parser is looked up from the parsing context using the Parser class as the key.

Since:

Apache Tika 0.4, major changes in Tika 0.5

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
DelegatingParser()

Method Summary

Modifier and Type	Method	Description
protected Parser	getDelegateParser(ParseContext context)	Returns the parser instance to which parsing tasks should be delegated.
Set<MediaType>	getSupportedTypes(ParseContext context)	Returns the set of media types supported by this parser when used with the given parse context.
void	parse(InputStream stream, ContentHandler handler, Metadata metadata, ParseContext context)	Looks up the delegate parser from the parsing context and delegates the parse operation to it.

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegatingParser

public DelegatingParser()

Method Detail

getDelegateParser

protected Parser getDelegateParser(ParseContext context)

Returns the parser instance to which parsing tasks should be delegated. The default implementation looks up the delegate parser from the given parse context, and uses an EmptyParser instance as a fallback. Subclasses can override this method to implement alternative delegation strategies.

Parameters:

context - parse context

Returns:

delegate parser

Since:

Apache Tika 0.7

getSupportedTypes

public Set<MediaType> getSupportedTypes(ParseContext context)

Description copied from interface: Parser

Returns the set of media types supported by this parser when used with the given parse context.

Specified by:

getSupportedTypes in interface Parser

Parameters:

context - parse context

Returns:

immutable set of media types

parse

public void parse(InputStream stream,
                  ContentHandler handler,
                  Metadata metadata,
                  ParseContext context)
           throws SAXException,
                  IOException,
                  TikaException

Looks up the delegate parser from the parsing context and delegates the parse operation to it. If a delegate parser is not found, then an empty XHTML document is returned.

Subclasses should override this method to parse the top level structure of the given document stream. Parsed sub-streams can be passed to this base class method to be parsed by the configured delegate parser.

Specified by:

parse in interface Parser

Parameters:

stream - the document stream (input)

handler - handler for the XHTML SAX events (output)

metadata - document metadata (input and output)

context - parse context

Throws:

SAXException - if the SAX events could not be processed

IOException - if the document stream could not be read

TikaException - if the document could not be parsed