org.apache.tika.parser

Class RecursiveParserWrapper

java.lang.Object

org.apache.tika.parser.RecursiveParserWrapper

All Implemented Interfaces:

Serializable, Parser

public class RecursiveParserWrapper
extends Object
implements Parser

This is a helper class that wraps a parser in a recursive handler. It takes care of setting the embedded parser in the ParseContext and handling the embedded path calculations.

After parsing a document, call getMetadata() to retrieve a list of Metadata objects, one for each embedded resource. The first item in the list will contain the Metadata for the outer container file.

Content can also be extracted and stored in the TIKA_CONTENT field of a Metadata object. Select the type of content to be stored at initialization.

If a WriteLimitReachedException is encountered, the wrapper will stop processing the current resource, and it will not process any of the child resources for the given resource. However, it will try to parse as much as it can. If a WLRE is reached in the parent document, no child resources will be parsed.

The implementation is based on Jukka's RecursiveMetadataParser and Nick's additions. See: RecursiveMetadataParser.

Note that this wrapper holds all data in memory and is not appropriate for files with content too large to be held in memory.

Note, too, that this wrapper is not thread safe because it stores state. The client must initialize a new wrapper for each thread, and the client is responsible for calling reset() after each parse.

The unit tests for this class are in the tika-parsers module.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Property	EMBEDDED_EXCEPTION
static Property	EMBEDDED_RESOURCE_LIMIT_REACHED
static Property	EMBEDDED_RESOURCE_PATH
static Property	PARSE_TIME_MILLIS
static Property	TIKA_CONTENT
static Property	WRITE_LIMIT_REACHED

Constructor Summary

Constructors

Constructor and Description
RecursiveParserWrapper(Parser wrappedParser, ContentHandlerFactory contentHandlerFactory) Initialize the wrapper with catchEmbeddedExceptions set to true as default.
RecursiveParserWrapper(Parser wrappedParser, ContentHandlerFactory contentHandlerFactory, boolean catchEmbeddedExceptions) Initialize the wrapper.

Method Summary

Methods

Modifier and Type	Method and Description
List<Metadata>	getMetadata() The first element in the returned list represents the data from the outer container file.
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 ignore, Metadata metadata, ParseContext context) Acts like a regular parser except it ignores the ContentHandler and it automatically sets/overwrites the embedded Parser in the ParseContext object.
void	reset() This clears the metadata list and resets unknownCount and hitMaxEmbeddedResources
void	setMaxEmbeddedResources(int max) Set the maximum number of embedded resources to store.

Methods inherited from class java.lang.Object

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

Field Detail

TIKA_CONTENT

public static final Property TIKA_CONTENT

PARSE_TIME_MILLIS

public static final Property PARSE_TIME_MILLIS

WRITE_LIMIT_REACHED

public static final Property WRITE_LIMIT_REACHED

EMBEDDED_RESOURCE_LIMIT_REACHED

public static final Property EMBEDDED_RESOURCE_LIMIT_REACHED

EMBEDDED_EXCEPTION

public static final Property EMBEDDED_EXCEPTION

EMBEDDED_RESOURCE_PATH

public static final Property EMBEDDED_RESOURCE_PATH

Constructor Detail

RecursiveParserWrapper

public RecursiveParserWrapper(Parser wrappedParser,
                      ContentHandlerFactory contentHandlerFactory)

Initialize the wrapper with catchEmbeddedExceptions set to true as default.

Parameters:

wrappedParser - parser to use for the container documents and the embedded documents

contentHandlerFactory - factory to use to generate a new content handler for the container document and each embedded document

RecursiveParserWrapper

public RecursiveParserWrapper(Parser wrappedParser,
                      ContentHandlerFactory contentHandlerFactory,
                      boolean catchEmbeddedExceptions)

Initialize the wrapper.

Parameters:

wrappedParser - parser to use for the container documents and the embedded documents

contentHandlerFactory - factory to use to generate a new content handler for the container document and each embedded document

catchEmbeddedExceptions - whether or not to catch the embedded exceptions. If set to true, the stack traces will be stored in the metadata object with key: EMBEDDED_EXCEPTION.

Method Detail

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 ignore,
         Metadata metadata,
         ParseContext context)
           throws IOException,
                  SAXException,
                  TikaException

Acts like a regular parser except it ignores the ContentHandler and it automatically sets/overwrites the embedded Parser in the ParseContext object.

To retrieve the results of the parse, use getMetadata().

Make sure to call reset() after each parse.

Specified by:

parse in interface Parser

Parameters:

stream - the document stream (input)

ignore - handler for the XHTML SAX events (output)

metadata - document metadata (input and output)

context - parse context

Throws:

IOException - if the document stream could not be read

SAXException - if the SAX events could not be processed

TikaException - if the document could not be parsed

getMetadata

public List<Metadata> getMetadata()

The first element in the returned list represents the data from the outer container file. There is no guarantee about the ordering of the list after that.

Returns:

list of Metadata objects that were gathered during the parse

setMaxEmbeddedResources

public void setMaxEmbeddedResources(int max)

Set the maximum number of embedded resources to store. If the max is hit during parsing, the EMBEDDED_RESOURCE_LIMIT_REACHED property will be added to the container document's Metadata.

If this value is < 0 (the default), the wrapper will store all Metadata.

Parameters:

max - maximum number of embedded resources to store

reset

public void reset()

This clears the metadata list and resets unknownCount and hitMaxEmbeddedResources