Package com.norconex.collector.http.checksum.impl

Class LastModifiedMetadataChecksummer

java.lang.Object

com.norconex.collector.core.checksum.AbstractMetadataChecksummer

com.norconex.collector.http.checksum.impl.LastModifiedMetadataChecksummer

All Implemented Interfaces:

IMetadataChecksummer, IXMLConfigurable

public class LastModifiedMetadataChecksummer
extends AbstractMetadataChecksummer

Default implementation of IMetadataChecksummer for the Norconex HTTP Collector which simply returns the exact value of the "Last-Modified" HTTP header field, or null if not present.

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 CrawlDocMetadata.CHECKSUM_METADATA.

To use different fields (one or several) to constitute a checksum, you can instead use the GenericMetadataChecksummer.

XML configuration usage:

<metadataChecksummer
    class="com.norconex.collector.http.checksum.impl.LastModifiedMetadataChecksummer"
    keep="[false|true]"
    toField="(field to store checksum)"/>

XML usage example:

<metadataChecksummer
    keep="true"
    toField="metaChecksum"/>

The above example will store the last modified date used for checksum purposes in a field called "metaChecksum".

Since 2.0.0, a self-closing <metadataChecksummer/> tag without any attributes is used to disable checksum generation.

Since:

2.2.0

Author:

Pascal Essiembre

See Also:

• GenericMetadataChecksummer

Constructor Summary

Constructors

Constructor	Description
LastModifiedMetadataChecksummer()

Method Summary

Modifier and Type	Method	Description
protected String	doCreateMetaChecksum(Properties metadata)
boolean	equals(Object other)
int	hashCode()
boolean	isDisabled()	Deprecated. Since 2.0.0, not having a checksummer defined or setting one explicitly to null effectively disables it.
protected void	loadChecksummerFromXML(XML xml)
protected void	saveChecksummerToXML(XML xml)
void	setDisabled(boolean disabled)	Deprecated. Since 2.0.0, not having a checksummer defined or setting one explicitly to null effectively disable it.
String	toString()

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

createMetadataChecksum, getOnSet, getTargetField, getToField, isKeep, loadFromXML, saveToXML, setKeep, setOnSet, setTargetField, setToField

Methods inherited from class java.lang.Object

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

Constructor Details

LastModifiedMetadataChecksummer

public LastModifiedMetadataChecksummer()

Method Details

doCreateMetaChecksum

protected String doCreateMetaChecksum(Properties metadata)

Specified by:

doCreateMetaChecksum in class AbstractMetadataChecksummer

isDisabled

@Deprecated
public boolean isDisabled()

Deprecated.

Since 2.0.0, not having a checksummer defined or setting one explicitly to null effectively disables it.

Deprecated.

Returns:

always false

setDisabled

@Deprecated
public void setDisabled(boolean disabled)

Deprecated.

Since 2.0.0, not having a checksummer defined or setting one explicitly to null effectively disable it.

Deprecated. Invoking this method has no effect

Parameters:

disabled - argument is ignored

loadChecksummerFromXML

protected void loadChecksummerFromXML(XML xml)

Specified by:

loadChecksummerFromXML in class AbstractMetadataChecksummer

saveChecksummerToXML

protected void saveChecksummerToXML(XML xml)

Specified by:

saveChecksummerToXML in class AbstractMetadataChecksummer

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