SRW/U for DSpace Ralph LeVan Research Scientist

What is SRW/U A Pair of HTTP-based Text Query Protocols – SRW: Search and Retrieve Web Service – SRU: Search and Retrieve URL Service An alternative to Z39.50

The Weaknesses of Classic Z39.50 Not popular with the Web community – Connection-based Sessions – Binary Encoding – Transmitted directly over TCP/IP Complicated

The Strengths of Classic Z39.50 Result Sets (a.k.a. Statefulness) Abstraction – Abstract Access Points (Attribute Sets) – Abstract Record Schemas Explain

SRW: Search and Retrieve Web Service SOAP (Simple Object Access Protocol) Based – HTTP – XML Records Described in WSDL (Web Service Description Language) 3 Services: SearchRetrieve, Scan and Explain

SRW: The Basics Only one database per request String (not structure) based queries Index Sets, not Attribute Sets One Record Syntax (XML)

The Explain Request An empty request – E.g.

The Explain Response A description of the database A list of the supported indexes A list of the supported record schemas

The SearchRetrieve Request String CQL Query Integer StartRecord Integer MaximumRecords String RecordSchema dog

The SearchRetrieve Response ResultSetReference – String resultSetName – Integer resultSetTimeToLive Integer numberOfRecords Records Diagnostics

CQL: Common Query Language Loosely based on CCL Search Boolean & Proximity Operators Index Sets & Indexes Truncation Characters *, # & ? Example: dc.title=harry potter or bib1.isbn= x

The Scan Request String CQL scanClause Integer maximumTerms Integer responsePosition on=scan&scanClause=dog&maximumTerms= 3&responsePosition=3

The Scan Response Terms – A term for searching – Possibly a term for displaying – The number of records retrieved by the term Diagnostics

Using SRU Send the URL and get the response BufferedReader in = new BufferedReader( new InputStreamReader(new URL( String inputLine=null, response; StringBuffer content=new StringBuffer(); while((inputLine=in.readLine())!=null) content.append(inputLine); response=content.toString();

Using SRU Parse the response using String methods int i=response.indexOf(, j=response.indexOf( ), count=Integer.parseInt(response.substring(i+17, j);

Using SRU Parse the response using DOM classes DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new InputSource(new StringReader(record)));

Using SRW Get WSDL from server or LOC or w-sample-service.wsdl

Using SRW Convert WSDL to code java org.apache.axis.wsdl.WSDL2Java --server- side --skeletonDeploy true srw-sample- service.wsdl

Using SRW Write Client SRWSampleServiceLocator service=new SRWSampleServiceLocator(); URL url=new URL(" SRWPort port=service.getSRW(url); SearchRetrieveRequestType request=new SearchRetrieveRequestType(); request.setQuery(dog"); SearchRetrieveResponseType response= port.searchRetrieveOperation(request); int postings=response.getNumberOfRecords());

DSpace Implementation Reads list of Lucene indexes from SRWDatabase.props Converts CQL queries to Lucene queries Gets Dublin Core record from database

Installation Get the SRW.war file from Start tomcat (to unpack the.war file) Edit the SRWServer.props configuration file Copy the SRWDatabase.props file to your DSpace/config directory Restart tomcat

SRWServer.props # parameters for the SRW Servlet SRW.Home=d:/Apache Tomcat 4.1/webapps/SRW/ default.database=DSpace resultSetIdleTime=300 db.DSpace.class=ORG.oclc.os.SRW.SRWLuceneDatabase db.DSpace.home=d:/dspace/dspace-1.1/ db.DSpace.configuration=config/SRWDatabase.props

Examples

Links ace.ppt ace.ppt

& Q uestions A A nswers