OAITMPlugin
From Gcube Wiki
OAI TM Plugin is a plugin of the Tree Based Access Facilities that allows harvesting of metadata descriptions of the records in an archive, using The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).
Each OAI Record is transformed in a edge-labelled tree by OAI TM Plugin.
Plugin parameters fields
Plugins lead to the creation of one or more collections. Thus, in addition to the information below, the user should specify collection name and description.
In order to instruct a Plugin on how to perform the harvesting, a user should specify the following mandatory information:
- repository name: the name of the repository to be harvested, e.g. "aquacomm";
- base URL: the base URL of the repository, e.g. "http://aquacomm.fcla.edu/cgi/oai2";
- default metadata format: the metadata format to be used for harvesting, e.g. "oai_dc";
- title XPath: the expression for identifying the title of the harvested resource, e.g. "//*[local-name()='title']";
In addition to that, the user might specify the following information:
- content XPath: the expression for identifying the content of the harvested resource, e.g. "//*[local-name()='identifier' and contains(.,'://')]";
- alternatives XPath: the expression for identifying additional content of the harvested resource, e.g. "//*[local-name()='relation' and contains(.,'://')]";
- set Identifiers List: the list of id of the sets to take into consideration during the harvesting phase;
Two typologies of plugins have been defined:
- WrapSetsRequest: to create a collection for each set of the external repository or for each set specified in the setIdentifierList;
- WrapRepositoryRequest: to create a single collection containing the whole content of the repository or the content of the sets specified in the setIdentifierList;
Tree model
Conceptual Schema
Each collection item produced by this plugin is characterised by the following information:
- item metadata: global information on the item including
- title: the title of the record;
- collectionID: the collection this item belongs to;
- creationTime: the time the item was created;
- lastUpdateTime: the most recent time the item has been updated;
- provenance: It is characterised by the following information:
- statement: "This item has been created by the gCube "+ pluginName +" via OAI-PMH metadata harvesting from the metadata provider "+repositoryName+" at "+baseURL;
- setID: the repository set the object belongs to (optional and repeatable);
- recordID: the identifier of the metadata record;
- metadata (repeatable): the metadata record harvested. It is characterised by the following information:
- schema: the metadata format of the metadata record;
- schemaLocation: the metadata format schema URI;
- record: the manifestation of the metadata record harvested;
- content (repeatable): any potential payload shipped with the metadata record. It is characterised by the following information:
- contentType: i.e. whether main or alternative content;
- mimeType: MIME type of the actual content;
- url: URL to the actual content;
XML Schema
The XML Schema of "record" element depends on the schema used to define record formats. This is a XML Schema of oai_dc record.
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified" > <xs:element name="t:root" > <xs:complexType> <xs:sequence> <xs:element name="title" type="xs:string" /> <xs:element name="collectionID" type="xs:string" /> <xs:element name="creationTime" type="xs:string" /> <xs:element name="lastUpdateTime" type="xs:string" /> <xs:element name="provenance" > <xs:complexType> <xs:sequence> <xs:element name="statement" type="xs:string" /> <xs:element name="setID" type="xs:string" maxOccurs="unbounded" /> <xs:element name="recordID" type="xs:string" /> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="metadata" > <xs:complexType> <xs:sequence> <xs:element name="schema" type="xs:string" /> <xs:element name="schemaLocation" type="xs:string" /> <xsd:element name="record"> <xsd:complexType> <xsd:sequence> <xs:element name="oai_dc:dc" > <xs:complexType> <xs:sequence> <xs:element name="dc:title" type="xs:string" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:creator" maxOccurs="unbounded" type="xs:string" /> <xs:element name="dc:subject" maxOccurs="unbounded" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:description" type="xs:string" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:publisher" type="xs:string" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:contributor" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:date" type="xs:date" /> <xs:element name="dc:type" maxOccurs="unbounded" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:format" type="xs:string" /> <xs:element name="dc:identifier" type="xs:string" /> <xs:element name="dc:source" type="xs:string" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:language" type="xs:string" /> <xs:element name="dc:relation" type="xs:string" /> <xs:element name="dc:coverage" maxOccurs="unbounded" > <xs:complexType> <xs:attribute name="xml:lang" type="xs:string" /> </xs:complexType> </xs:element> <xs:element name="dc:rights" type="xs:string" /> </xs:sequence> <xs:attribute name="xmlns:oai_dc" type="xs:string" /> <xs:attribute name="xmlns:xsi" type="xs:string" /> <xs:attribute name="xmlns:dc" type="xs:string" /> <xs:attribute name="xsi:schemaLocation" type="xs:string" /> </xs:complexType> </xs:element> </xsd:sequence> </xsd:complexType> </xsd:element> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="content" maxOccurs="unbounded" minOccurs="0"> <xs:complexType> <xs:sequence> <xs:element name="contentType" type="xs:string" /> <xs:element name="mimeType" type="xs:string" /> <xs:element name="url" type="xs:string" /> </xs:sequence> </xs:complexType> </xs:element> </xs:sequence> <xs:attribute name="xmlns:t" type="xs:string" /> <xs:attribute name="t:id" type="xs:string" /> </xs:complexType> </xs:element> </xs:schema>
Example
A tree generated by OAI TM Plugin looks like the XML code below. The original record is available at this link: | oai:ojs.ijict.org:article/377.
<?xml version="1.0" ?> <t:root xmlns:t="http://gcube-system.org/namespaces/data/trees" t:id="oai:ojs.ijict.org:article/377"> <title></title> <collectionID>ijoat:OTHR</collectionID> <creationTime>2012-01-16T08:08:09.000+01:00</creationTime> <lastUpdateTime>2012-01-16T08:08:09.000+01:00</lastUpdateTime> <provenance> <statement>This item has been created by the gCube OAI-TM plugin via OAI-PMH metadata harvesting from the metadata provider null at http://ijict.org/index.php/ijoat/oai</statement> <recordID>oai:ojs.ijict.org:article/377</recordID> </provenance> <metadata> <schema>oai_dc</schema> <schemaLocation>http://www.openarchives.org/OAI/2.0/oai_dc/ </schemaLocation> <record> <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd" xmlns:dc="http://purl.org/dc/elements/1.1/"> <dc:title xml:lang="en-US">Collective Intelligence based Framework for Load Balancing of Web Servers</dc:title> <dc:creator>Atul Garg</dc:creator> <dc:creator>Dimple Juneja</dc:creator> <dc:subject xml:lang="en-US"></dc:subject> <dc:subject xml:lang="en-US"></dc:subject> <dc:subject xml:lang="en-US"></dc:subject> <dc:description xml:lang="en-US">The paper exploits the collective intelligence referred to as ant intelligence in World Wide Web with the aim to improve the performance of online web servers by balancing the load. The central concept of this idea is that a collection of agents can individually perform relatively simple, self-centered actions, such as the selection or rejection of hyperlinks in a web page for navigation, computing the load of server and aggregate these individual actions into a common substrate. The common substrate can then be evaluated to find the best available server to perform the task. This work aims to address the challenge of distributing intelligence to World Wide Web by contributing a unique ant-based intelligent load balancing framework which is able to integrate and synthesize knowledge on a scale far beyond the capabilities of individual humans. </dc:description> <dc:publisher xml:lang="en-US">International Journal of Advancements in Technology</dc:publisher> <dc:contributor xml:lang="en-US"></dc:contributor> <dc:date>2012-01-18</dc:date> <dc:type xml:lang="en-US"></dc:type> <dc:type xml:lang="en-US"></dc:type> <dc:format>application/pdf</dc:format> <dc:identifier>http://ijict.org/index.php/ijoat/article/view/load-balancing-of-web-servers </dc:identifier> <dc:source xml:lang="en-US">International Journal of Advancements in Technology; Vol 3, No 1 (2012): International Journal of Advancements in Technology; 64-70</dc:source> <dc:language>en</dc:language> <dc:relation>http://ijict.org/index.php/ijoat/article/download/load-balancing-of-web-servers/1050 </dc:relation> <dc:coverage xml:lang="en-US"></dc:coverage> <dc:coverage xml:lang="en-US"></dc:coverage> <dc:coverage xml:lang="en-US"></dc:coverage> <dc:rights>Authors who publish with this journal agree to the following terms:<br /> <ol type="a"><br /><li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <a href="http://creativecommons.org/licenses/by/3.0/" target="_new">Creative Commons Attribution License</a> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li><br /><li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li><br /><li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li></ol></dc:rights> </oai_dc:dc> </record> </metadata> <content> <contentType></contentType> <mimeType></mimeType> <url></url> </content> </t:root>
Maven coordinates
The Maven coordinates of oai-tree-plugin of its development versions are:
<dependency> <groupId>org.gcube.data.oai.tmplugin</groupId> <artifactId>oai-tm-plugin</artifactId> <version>1.1.0-2.13.0</version> </dependency>
The oai-harvester library is available here:
<dependency> <groupId>org.gcube.common</groupId> <artifactId>oaiharvester</artifactId> <version>1.1.0</version> </dependency>
