com.norconex.collector.core.checksum.impl

Class GenericMetadataChecksummer

java.lang.Object

com.norconex.collector.core.checksum.AbstractMetadataChecksummer

com.norconex.collector.core.checksum.impl.GenericMetadataChecksummer

All Implemented Interfaces:

IMetadataChecksummer, IXMLConfigurable

public class GenericMetadataChecksummer
extends AbstractMetadataChecksummer

Generic implementation of IMetadataChecksummer that uses specified source field names and their values for the checksum. The name and values are simply returned as is, joined using this format: fieldName=fieldValue;fieldName=fieldValue;....

You have the option to keep the checksum as a document metadata field. When AbstractMetadataChecksummer.setKeep(boolean) is true, the checksum will be stored in the target field name specified. If you do not specify any, it stores it under the metadata field name CollectorMetadata.COLLECTOR_CHECKSUM_METADATA.

Since 1.9.0, it is possible to use regular expressions to match fields. Use sourceFields to list all fields to use, separated by commas. Use sourceFieldsRegex to match fields to use using a regular expression. Both sourceFields and sourceFieldsRegex can be used together. Matching fields from both will be combined, in the order provided/matched, starting with sourceFields entries.

XML configuration usage:

  <metadataChecksummer 
      class="com.norconex.collector.core.checksum.impl.GenericMetadataChecksummer"
      disabled="[false|true]"
      keep="[false|true]"
      targetField="(field to store checksum)">
    <sourceFields>
        (optional coma-separated list fields used to create checksum)
    </sourceFields>
    <sourceFieldsRegex>
      (regular expression matching fields used to create checksum)
    </sourceFieldsRegex>    
  </metadataChecksummer>
 

Usage example:

The following uses a combination of two (fictitious) fields called "docLastModified" and "docSize" to make the checksum.

  <metadataChecksummer 
      class="com.norconex.collector.core.checksum.impl.GenericMetadataChecksummer">
    <sourceFields>docLastModified,docSize</sourceFields>
  </metadataChecksummer>
 

Since:

1.2.0

Author:

Pascal Essiembre

Constructor Summary

Constructors

Constructor and Description
GenericMetadataChecksummer()

Method Summary

Modifier and Type	Method and Description
protected String	doCreateMetaChecksum(Properties metadata)
boolean	equals(Object other)
String[]	getSourceFields() Gets the metadata fields used to construct a checksum.
String	getSourceFieldsRegex() Gets the regular expression matching metadata fields used to construct a checksum.
int	hashCode()
boolean	isDisabled() Whether this checksummer is disabled or not.
protected void	loadChecksummerFromXML(XMLConfiguration xml)
protected void	saveChecksummerToXML(EnhancedXMLStreamWriter writer)
void	setDisabled(boolean disabled) Sets whether this checksummer is disabled or not.
void	setSourceFields(String... fields) Sets the metadata header fields used construct a checksum.
void	setSourceFieldsRegex(String sourceFieldsRegex) Sets the regular expression matching metadata fields used construct a checksum.
String	toString()

Methods inherited from class com.norconex.collector.core.checksum.AbstractMetadataChecksummer

createMetadataChecksum, getTargetField, isKeep, loadFromXML, saveToXML, setKeep, setTargetField

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

GenericMetadataChecksummer

public GenericMetadataChecksummer()

Method Detail

doCreateMetaChecksum

protected String doCreateMetaChecksum(Properties metadata)

Specified by:

doCreateMetaChecksum in class AbstractMetadataChecksummer

getSourceFields

public String[] getSourceFields()

Gets the metadata fields used to construct a checksum.

Returns:

fields to use for checksum

setSourceFields

public void setSourceFields(String... fields)

Sets the metadata header fields used construct a checksum.

Parameters:

fields - fields to use for checksum

getSourceFieldsRegex

public String getSourceFieldsRegex()

Gets the regular expression matching metadata fields used to construct a checksum.

Returns:

regular expression

Since:

1.9.0

setSourceFieldsRegex

public void setSourceFieldsRegex(String sourceFieldsRegex)

Sets the regular expression matching metadata fields used construct a checksum.

Parameters:

sourceFieldsRegex - regular expression

Since:

1.9.0

isDisabled

public boolean isDisabled()

Whether this checksummer is disabled or not. When disabled, not checksum will be created (the checksum will be null).

Returns:

true if disabled

setDisabled

public void setDisabled(boolean disabled)

Sets whether this checksummer is disabled or not. When disabled, not checksum will be created (the checksum will be null).

Parameters:

disabled - true if disabled

loadChecksummerFromXML

protected void loadChecksummerFromXML(XMLConfiguration xml)

Specified by:

loadChecksummerFromXML in class AbstractMetadataChecksummer

saveChecksummerToXML

protected void saveChecksummerToXML(EnhancedXMLStreamWriter writer)
                             throws XMLStreamException

Specified by:

saveChecksummerToXML in class AbstractMetadataChecksummer

Throws:

XMLStreamException

equals

public boolean equals(Object other)

Overrides:

equals in class AbstractMetadataChecksummer

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractMetadataChecksummer

toString

public String toString()

Overrides:

toString in class AbstractMetadataChecksummer