SRU and Lucene

1
SRU and Lucene

• Ralph LeVan
• Research Scientist
• levan_at_oclc.org

2
SRU Overview

• A Simple Web Service
• Supports REST-ful and SOAP requests
• Responses are always XML records
• Supports Search and Retrieve
• Uses a Standard Query Grammar
• Supports Self-Configuring Clients
• A Gateway to Local Databases

3
SRU Features

• Explain Records
• CQL Query Grammar
• Persistent Result Sets
• XML Database Records Returned
• Index Browses
• Stylesheets

4
Explain Records

• serverInfo
• databaseInfo
• metaInfo
• indexInfo
• schemaInfo
• configInfo

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serverInfo

• Generated Automatically
• host
• port
• database

6
databaseInfo

• From SRWDatabase.props
• databaseInfo.title
• databaseInfo.description
• databaseInfo.contact
• Provided Automatically
• implementation

7
metaInfo

• From SRWDatabase.props
• metaInfo.dateModified
• metaInfo.aggregatedFrom
• metaInfo.dateAggregated

8
indexInfo

• Generated Automatically
• local index set and Lucene index names
• From SRWDatabase.props
• qualifier.ltindexSetgt.ltindexNamegt
  ltLuceneIndexNamegt
• Used only if you want to map other index names to
  your Lucene indexes (e.g. qualifier.dc.identifier
  id)

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schemaInfo

• Generated Automatically
• LuceneDocument
• From SRWDatabase.props
• xmlSchemasltlist of namegt
• ltschemaNamegt.identifier
• ltschemaNamegt.location
• ltschemaNamegt.namespace
• ltschemaNamegt.title
• ltschemaNamegt.transformer
• ltschemaNamegt.resolver

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schemaInfo Example

• xmlSchemasLuceneDocument, DC
• LuceneDocument.identifierinfosrw/schema/1/Lucene
  Document
• LuceneDocument.locationhttp//www.oclc.org/standa
  rds/Lucene/schema/LuceneDocument.xsd
• LuceneDocument.namespacehttp//www.oclc.org/Lucen
  eDocument
• LuceneDocument.titleLucene Demo Database records
  in their internal format

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schemaInfo Example (cont.)

• DC.identifierinfosrw/schema/1/dc-v1.1
• DC.locationhttp//www.loc.gov/zing/srw/dc-schema.
  xsd
• DC.titleDC Dublin Core Elements
• DC.transformerLuceneToDC.xsl

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configInfo

• Generated Automatically
• maximumRecords (20)
• numberOfRecords (10)
• resultSetTTL (300)
• From SRWDatabase.props
• configInfo.maximumRecords
• configInfo.numberOfRecords
• configInfo.resultSetTTL

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CQL Query Grammar

• Builtin BasicLuceneQueryTranslator
• CqlQueryTranslator
• Query makeQuery(CQLNode cn)
• Term getTerm()
• From SRWDatabase.props
• SRWLuceneDatabase. CqlToLuceneQueryTranslator
  ltClassNamegt

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Persistent Result Sets

• Builtin LuceneQueryResult

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XML Database Records

• Builtin BasicLuceneRecordResolver
• RecordResolver
• Void init(Properties props)
• Record resolve(Document doc, String IdFieldName,
  ExtraDataType extraDataType)
• From SRWDatabase.props
• ltschemaNamegt.resolverltClassNamegt
• SRWLuceneDatabase.idFieldName ltFieldNamegt

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Index Browses

• Builtin SRWLuceneDatabase.getTerms()

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Stylesheets

• From SRWDatabase.props
• explainStyleSheet /SRW/explainResponse.xsl
• scanStyleSheet/SRW/scanResponse.xsl
• searchStyleSheet /SRW/searchRetrieveResponse.xsl

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Making the Magic Happen

• Drop the SRWLucene.war into your lttomcatgt/webapps
  directory
• Restart Tomcat
• Edit lttomcatgt/webapps/SRWLucene/WEB-INF/classes/SR
  WServer.props
• Restart Tomcat

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Sample SRWServer.props

• db.LuceneDemoDB.class ORG.oclc.os.SRW.Lucene.SRWL
  uceneDatabase
• db.LuceneDemoDB.home f/lucene-2.0.0
• db.LuceneDemoDB.configuration SRWDatabase.props

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Sample SRWDatabase.props

• databaseInfo.titleLucene Demo Database
• databaseInfo.descriptionAn index of the source
  code for Lucene
• databaseInfo.contactRalph LeVan (levan_at_oclc.org)
• qualifier.cql.serverChoicecontents
• explainStyleSheet/SRWLucene/explainResponse.xsl
• scanStyleSheet/SRWLucene/scanResponse.xsl
• searchStyleSheet /SRWLucene/searchRetrieveRespons
  e.xsl

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Resources

• http//www.oclc.org/research/software/srw
• http//staff.oclc.org/levan/SRWLuceneSource.jar
• http//staff.oclc.org/levan/SRWLucene.war
• http//staff.oclc.org/levan/Implementing20an20S
  RWLuceneDatabase.doc
• http//staff.oclc.org/levan/SRU20and20Lucene.pp
  t
• http//alcme.oclc.org/srw/SRUServerTester.html