Package com.digitalpebble.stormcrawler.util

Class MetadataTransfer

java.lang.Object

com.digitalpebble.stormcrawler.util.MetadataTransfer

public class MetadataTransfer
extends Object

Implements the logic of how the metadata should be passed to the outlinks, what should be stored back in the persistence layer etc...

Field Summary

Fields

Modifier and Type	Field	Description
static String	depthKeyName	Metadata key name for tracking the depth
static String	maxDepthKeyName	Metadata key name for tracking a non-default max depth
static String	metadataPersistParamName	Parameter name indicating which metadata to persist for a given document but not transfer to outlinks.
static String	metadataTransferClassParamName	Class to use for transfering metadata to outlinks.
static String	metadataTransferParamName	Parameter name indicating which metadata to transfer to the outlinks and persist for a given document.
static String	trackDepthParamName	Parameter name indicating whether to track the depth from seed.
static String	trackPathParamName	Parameter name indicating whether to track the url path or not.
static String	urlPathKeyName	Metadata key name for tracking the source URLs

Constructor Summary

Constructors

Constructor	Description
MetadataTransfer()

Method Summary

Modifier and Type	Method	Description
protected void	configure(Map<String,Object> conf)
Metadata	filter(Metadata metadata)	Determine which metadata should be persisted for a given document including those which are not necessarily transferred to the outlinks
static MetadataTransfer	getInstance(Map<String,Object> conf)
Metadata	getMetaForOutlink(String targetURL, String sourceURL, Metadata parentMD)	Determine which metadata should be transferred to an outlink.

Methods inherited from class java.lang.Object

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

Field Detail

metadataTransferClassParamName

public static final String metadataTransferClassParamName

Class to use for transfering metadata to outlinks. Must extend the class MetadataTransfer.

See Also:

Constant Field Values

metadataTransferParamName

public static final String metadataTransferParamName

Parameter name indicating which metadata to transfer to the outlinks and persist for a given document. Value is either a vector or a single valued String.

See Also:

Constant Field Values

metadataPersistParamName

public static final String metadataPersistParamName

Parameter name indicating which metadata to persist for a given document but not transfer to outlinks. Value is either a vector or a single valued String.

See Also:

Constant Field Values

trackPathParamName

public static final String trackPathParamName

Parameter name indicating whether to track the url path or not. Boolean value, true by default.

See Also:

Constant Field Values

trackDepthParamName

public static final String trackDepthParamName

Parameter name indicating whether to track the depth from seed. Boolean value, true by default.

See Also:

Constant Field Values

urlPathKeyName

public static final String urlPathKeyName

Metadata key name for tracking the source URLs

See Also:

Constant Field Values

depthKeyName

public static final String depthKeyName

Metadata key name for tracking the depth

See Also:

Constant Field Values

maxDepthKeyName

public static final String maxDepthKeyName

Metadata key name for tracking a non-default max depth

See Also:

Constant Field Values

Constructor Detail

MetadataTransfer

public MetadataTransfer()

Method Detail

getInstance

public static MetadataTransfer getInstance(Map<String,Object> conf)

configure

protected void configure(Map<String,Object> conf)

getMetaForOutlink

public Metadata getMetaForOutlink(String targetURL,
                                  String sourceURL,
                                  Metadata parentMD)

Determine which metadata should be transferred to an outlink. Adds additional metadata like the URL path.

filter

public Metadata filter(Metadata metadata)

Determine which metadata should be persisted for a given document including those which are not necessarily transferred to the outlinks