For more details about OAI-PMH see the documentation: http://www.openarchives.org/pmh/

OAI-PMH Component

The oaipmh component is used for polling OAI-PMH data providers. Camel will default poll the provider every 60th seconds.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>es.upm.oeg.camel</groupId>
    <artifactId>camel-oaipmh</artifactId>
    <version>x.x.x</version>
</dependency>

Note: The component currently only supports polling (consuming) feeds.

Note: You must include this repository in your pom.xml:

<repositories>
    <!-- GitHub Repository -->
    <repository>
        <id>camel-oaipmh-mvn-repo</id>
        <url>https://raw.github.com/cbadenes/camel-oaipmh/mvn-repo/</url>
        <snapshots>
            <enabled>true</enabled>
            <updatePolicy>always</updatePolicy>
        </snapshots>
    </repository>
</repositories>

URI format

oaipmh:oaipmhURI

Where oaipmhURI is the URI to the OAI-PMH data provider to poll.

You can append query options to the URI in the following format, ?option=value&option=value&...

Options

Property	Default	Description
delay	60000	Delay in milliseconds between each poll
initialDelay	1000	Milliseconds before polling starts
userFixedDelay	false	Set to true to use fixed delay between pools, otherwise fixed rate is used. See ScheduledExecutorService in JDK for details.
verb	ListRecords	Future versions will handle ListIdentifiers, Identify, GetRecord, ListSets and ListMetadataFormats.
metadataPrefix	oai_dc	Specifies the metadataPrefix of the format that should be included in the metadata part of the returned records.
from		Specifies a lower bound for datestamp-based selective harvesting. UTC DateTime value. After first request, this value is updated to current time if no upper bound is defined
until		Specifies an upper bound for datestamp-based selective harvesting. UTC DateTime value.
set		Specifies membership as a criteria for set-based selective harvesting.

Exchange data types

Camel initializes the IN body on the Exchange with a response message in XML format. For ListXX requests, Camel will return a message for each element of the list received.

OAI-PMH Data Format

The oaipmh component ships with an OAIPMH dataformat that can be used to convert between String (XML) and OAIPMHType model object (JaxB).

• marshal = from OAIPMHType to XML String
• unmarshal = from XML String to OAIPMHType More details about these xsd here.

A route using this would look something like this:

from("oaipmh://aprendeenlinea.udea.edu.co/revistas/index.php/ingenieria/oai?delay=60000").unmarshal().jaxb("es.upm.oeg.camel.oaipmh.model").to("mock:result");

The purpose of this feature is to make it possible to use Camel's lovely built-in expressions for manipulating OAI-PMH messages. As show below, an XPath expression can be used to filter the OAI-PMH message:

from("oaipmh://aprendeenlinea.udea.edu.co/revistas/index.php/ingenieria/oai?delay=60000").unmarshal().jaxb("es.upm.oeg.camel.oaipmh.model").filter().xpath("//item/request/set[contains(.,'physics')]").to("mock:result");

This work is funded by the EC-funded project DrInventor (www.drinventor.eu).