| 1 | <!doctype html public "-//w3c//dtd html 4.0 transitional//en">
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| 2 | <html>
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| 3 | <head>
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| 4 | <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
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| 5 | <meta name="GENERATOR" content="Mozilla/4.76 [en] (X11; U; Linux 2.2.16-22 i686) [Netscape]">
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| 6 | <title>: Package org.nzdl.gsdl.service</title>
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| 7 | <!--NewPage-->
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| 8 | <!-- Generated by javadoc on Thu Mar 08 23:01:13 GMT+13:00 2001 -->
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| 9 | </head>
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| 10 | <body bgcolor="#FFFFFF">
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| 11 | Provides services for java client-side communication
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| 12 | to a Greenstone Digital Library via CORBA.
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| 13 | <p><b>See:</b>
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| 14 | <br> <b><a href="#package_description">Description</a></b>
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| 15 | <table BORDER CELLSPACING=0 CELLPADDING=3 WIDTH="100%" >
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| 16 | <tr BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
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| 17 | <td COLSPAN="2"><b><font size=+2>Interface Summary</font></b></td>
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| 18 | </tr>
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| 19 |
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| 20 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 21 | <td WIDTH="15%"><b><i><a href="NzdlService.html">NzdlService</a></i></b></td>
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| 22 |
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| 23 | <td>An object that services CORBA client requests to a Greenstone Digital
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| 24 | Library.</td>
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| 25 | </tr>
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| 26 | </table>
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| 27 |
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| 28 | <table BORDER CELLSPACING=0 CELLPADDING=3 WIDTH="100%" >
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| 29 | <tr BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
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| 30 | <td COLSPAN="2"><b><font size=+2>Class Summary</font></b></td>
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| 31 | </tr>
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| 32 |
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| 33 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 34 | <td WIDTH="15%"><b><a href="NzdlCollectionInfo.html">NzdlCollectionInfo</a></b></td>
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| 35 |
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| 36 | <td>An object that stores information on a collection.</td>
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| 37 | </tr>
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| 38 |
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| 39 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 40 | <td WIDTH="15%"><b><a href="NzdlQuery.html">NzdlQuery</a></b></td>
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| 41 |
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| 42 | <td>NzdlQuery is an object that holds the options for a query and is easily
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| 43 | configured by the user.</td>
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| 44 | </tr>
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| 45 |
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| 46 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 47 | <td WIDTH="15%"><b><a href="NzdlQueryHit.html">NzdlQueryHit</a></b></td>
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| 48 |
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| 49 | <td>Holds a single result from a query.</td>
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| 50 | </tr>
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| 51 |
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| 52 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 53 | <td WIDTH="15%"><b><a href="NzdlRequest.html">NzdlRequest</a></b></td>
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| 54 |
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| 55 | <td>An object that holds CORBA request data ready for by servicing by <tt><a href="NzdlService.html">NzdlService</a></tt>.</td>
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| 56 | </tr>
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| 57 |
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| 58 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 59 | <td WIDTH="15%"><b><a href="NzdlResponse.html">NzdlResponse</a></b></td>
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| 60 |
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| 61 | <td>An object that holds data from a response after a <tt><a href="NzdlRequest.html">NzdlRequest</a></tt>
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| 62 | has been serviced by <tt><a href="NzdlService.html">NzdlService</a></tt>.</td>
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| 63 | </tr>
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| 64 |
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| 65 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 66 | <td WIDTH="15%"><b><a href="NzdlResultSet.html">NzdlResultSet</a></b></td>
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| 67 |
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| 68 | <td>An object that holds results extracted from a response by <tt><a href="NzdlResponse.html#getResultSet()">NzdlResponse.getResultSet()</a></tt>.</td>
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| 69 | </tr>
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| 70 |
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| 71 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 72 | <td WIDTH="15%"><b><a href="NzdlServiceClient.html">NzdlServiceClient</a></b></td>
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| 73 |
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| 74 | <td>Used to implement the <tt><a href="NzdlService.html">NzdlService</a></tt>
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| 75 | object.</td>
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| 76 | </tr>
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| 77 |
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| 78 | <tr BGCOLOR="#FFFFFF" CLASS="TableRowColor">
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| 79 | <td WIDTH="15%"><b><a href="NzdlServiceServer.html">NzdlServiceServer</a></b></td>
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| 80 |
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| 81 | <td>SimpleServer Based on algorithms in ...</td>
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| 82 | </tr>
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| 83 | </table>
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| 84 |
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| 85 | <p><a NAME="package_description"></a><!-- -->
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| 86 | <h2>
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| 87 | Package org.nzdl.gsdl.service Description</h2>
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| 88 | Provides services for java client-side communication to a Greenstone Digital
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| 89 | Library via CORBA.
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| 90 | <br>
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| 91 | <h2>
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| 92 | Further Requirements</h2>
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| 93 |
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| 94 | <ul>
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| 95 | <li>
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| 96 | Sun Java 2 version 1.3 (or later)</li>
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| 97 |
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| 98 | <li>
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| 99 | Corbaserver, a server-side application for communicating to a Greenstone
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| 100 | Digital Library.</li>
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| 101 | </ul>
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| 102 |
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| 103 | <h2>
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| 104 | Java Interface Data Flows</h2>
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| 105 |
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| 106 | <center><img SRC="nzdl-service-package.png" ALT="NZDL Data Flow Diagram" height=280 width=637></center>
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| 107 |
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| 108 | <p><br>
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| 109 | <h2>
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| 110 | A Typical Query</h2>
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| 111 | From a users perspective, a typical query may work as follows:
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| 112 | <ul>
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| 113 | <li>
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| 114 | Create instances of the necessary NZDL Java-Client objects:</li>
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| 115 |
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| 116 | <ul>
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| 117 | <li>
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| 118 | a <b>NzdlQuery</b> object</li>
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| 119 |
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| 120 | <li>
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| 121 | a <b>NzdlRequest </b>object using your <b>NzdlQuery</b> object</li>
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| 122 |
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| 123 | <li>
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| 124 | a <b>NzdlResponse</b> object that will eventually hold response
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| 125 | data</li>
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| 126 |
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| 127 | <li>
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| 128 | a <b>NzdlService</b> object to service CORBA interface requests
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| 129 | to a Greenstone collection</li>
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| 130 | </ul>
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| 131 |
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| 132 | <li>
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| 133 | Use the <b>NzdlService</b> object (with collection name and <b>NzdlRequest
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| 134 | </b>object)
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| 135 | to query the CORBA interface and place the reply into the <b>NzdlResponse</b>
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| 136 | object.</li>
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| 137 |
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| 138 | <li>
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| 139 | Create an instance of the <b>NzdlResultSet</b> object. Use <b>NzdlResponse.getResultSet()
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| 140 | </b>to
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| 141 | extract response data into the <b>NzdlResultSet</b> object.</li>
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| 142 |
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| 143 | <li>
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| 144 | Use the <b>NzdlResultSet</b> methods to view data such as document IDs</li>
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| 145 |
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| 146 | <br>Get documents using <b>NzdlService.getDocument()</b></ul>
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| 147 | <b></b>
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| 148 | <h1>
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| 149 | Sample Code</h1>
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| 150 | <tt>/**</tt>
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| 151 | <br><tt>* TrivialDemo.java.</tt>
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| 152 | <br><tt>* A very simple application that:</tt>
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| 153 | <br><tt>* - reads an Interoperable Object Reference (IOR) from a file;</tt>
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| 154 | <br><tt>* - lists all available collections;</tt>
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| 155 | <br><tt>* - searches "demo" collection for "snail farming";</tt>
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| 156 | <br><tt>* - prints the number of hits;</tt>
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| 157 | <br><tt>* - lists first 10 titles found;</tt>
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| 158 | <br><tt>* - displays the unformatted text of first document found.</tt>
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| 159 | <br><tt>*/</tt>
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| 160 | <br><tt>import java.io.*;</tt>
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| 161 | <br><tt>import java.util.*;</tt>
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| 162 | <br><tt>import java.lang.*;</tt>
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| 163 | <br><tt>import org.nzdl.gsdl.service.*; //the java-client stuff</tt>
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| 164 | <p><tt>public class TrivialDemo {</tt>
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| 165 | <br><tt> public static void main( String [] args )</tt>
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| 166 | <br><tt> {</tt>
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| 167 | <br><tt> String myIorFile = "/tmp/localcorba.objid";</tt>
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| 168 | <br><tt> String myQueryString = "snail farming";</tt>
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| 169 | <br><tt> String myCollection = "demo";</tt>
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| 170 | <p><tt> // Use NzdlService to create corba connection</tt>
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| 171 | <br><tt> NzdlService myService = new NzdlServiceClient</tt>
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| 172 | <br><tt>
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| 173 | ( null, null, getIor(myIorFile) );</tt>
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| 174 | <p><tt> // Use getCollectionSet to obtain List of Collections</tt>
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| 175 | <br><tt> Set myCollections = myService.getCollectionSet();</tt>
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| 176 | <p><tt> //Display List of Collections</tt>
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| 177 | <br><tt> System.out.println("\nThe available collections:");</tt>
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| 178 | <p><tt> for (Iterator i = myCollections.iterator(); i.hasNext();
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| 179 | )</tt>
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| 180 | <br><tt> {</tt>
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| 181 | <br><tt> String collName = (String)
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| 182 | i.next();</tt>
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| 183 | <br><tt> System.out.println("
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| 184 | "+ collName);</tt>
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| 185 | <br><tt> }</tt>
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| 186 | <p><tt> // Find The Number of documents in my collection</tt>
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| 187 | <br><tt> NzdlCollectionInfo myInfo = myService.getCollectionInfo(myCollection);</tt>
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| 188 | <br><tt> System.out.println("\nNum Of Collection docs
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| 189 | = "+myInfo.getNumOfDocs());</tt>
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| 190 | <br><tt> </tt>
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| 191 | <br><tt> // Create query object</tt>
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| 192 | <br><tt> NzdlQuery query = new NzdlQuery( myQueryString
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| 193 | );</tt><tt></tt>
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| 194 | <p><tt> // Create request object</tt>
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| 195 | <br><tt> NzdlRequest request = new NzdlRequest( query
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| 196 | );</tt><tt></tt>
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| 197 | <p><tt> // create response object</tt>
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| 198 | <br><tt> NzdlResponse response = new NzdlResponse( );</tt>
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| 199 | <br>
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| 200 | <br><tt> // use service to get response from request
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| 201 | to myCollection</tt>
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| 202 | <br><tt> myService.service( myCollection, request, response
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| 203 | );</tt>
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| 204 | <p><tt> // use getResultSet to get results from response</tt>
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| 205 | <br><tt> NzdlResultSet results = response.getResultSet();</tt><tt></tt>
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| 206 | <p><tt> // getNumOfDocs</tt>
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| 207 | <br><tt> System.out.println("\nNumber of hits = "+results.getNumOfDocs());</tt><tt></tt>
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| 208 | <p><tt> // Use getDocumentIDs to build list of titles
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| 209 | (defaults: 1 - 10)</tt>
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| 210 | <br><tt> List docIDs = results.getDocumentIDs();</tt>
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| 211 | <br><tt> System.out.println("\nThe titles:");</tt>
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| 212 | <br><tt> for (ListIterator i = docIDs.listIterator();
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| 213 | i.hasNext(); )</tt>
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| 214 | <br><tt> {</tt>
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| 215 | <br><tt> Set metaData</tt>
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| 216 | <br><tt> = myService.getMetaData(
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| 217 | myCollection,(String)i.next(),"Title");</tt>
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| 218 | <br><tt> Iterator j = metaData.iterator();</tt>
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| 219 | <br><tt> System.out.println(j.next());
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| 220 | //print title metadata</tt>
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| 221 | <br><tt> }</tt>
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| 222 | <br><tt> System.out.println("\nThe first document returned
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| 223 | was:");</tt>
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| 224 | <p><tt> // Print first document returned</tt>
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| 225 | <br><tt> String myDoc</tt>
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| 226 | <br><tt> = myService.getDocument(myCollection,(String)docIDs.get(0));</tt>
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| 227 | <br><tt> System.out.println(myDoc);</tt>
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| 228 | <p><tt> } // end of main</tt>
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| 229 | <br>
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| 230 | <p><tt> // Read the IOR from a file</tt>
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| 231 | <br><tt> static private String getIor(String sourceOfID)
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| 232 | {</tt>
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| 233 | <br><tt> String ior = null;</tt>
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| 234 | <br><tt> try</tt>
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| 235 | <br><tt> {</tt>
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| 236 | <br><tt> BufferedReader input</tt>
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| 237 | <br><tt>
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| 238 | = new BufferedReader(new FileReader(sourceOfID));</tt>
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| 239 | <br><tt> ior = input.readLine();</tt>
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| 240 | <br><tt> }</tt>
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| 241 | <br><tt> catch (java.io.IOException e)</tt>
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| 242 | <br><tt> {</tt>
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| 243 | <br><tt> System.err.println("Error
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| 244 | reading IOR key:\n" + e);</tt>
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| 245 | <br><tt> System.exit(1);</tt>
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| 246 | <br><tt> }</tt>
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| 247 | <br><tt> return ior;</tt>
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| 248 | <br><tt> } //end of getIors</tt><tt></tt>
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| 249 | <p><tt>} // end of demo class</tt>
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| 250 | <br>
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| 251 | </body>
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| 252 | </html>
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