Class 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 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