Edit File: removingredundantvalueclasses.html
<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title> Removing the Redundant Value Classes </title> <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.62.4" /> <link rel="home" href="index.html" title="Berkeley DB Collections Tutorial" /> <link rel="up" href="SerializableEntity.html" title="Chapter 6. 		Using Serializable Entities 	" /> <link rel="previous" href="transientfieldsinbinding.html" title=" 		Using Transient Fields in an Entity Binding 	" /> <link rel="next" href="Summary.html" title="Chapter 7. 		Summary 	" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center"> Removing the Redundant Value Classes </th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="transientfieldsinbinding.html">Prev</a> </td> <th width="60%" align="center">Chapter 6. Using Serializable Entities </th> <td width="20%" align="right"> <a accesskey="n" href="Summary.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="removingredundantvalueclasses"></a> Removing the Redundant Value Classes </h2> </div> </div> <div></div> </div> <p> The <tt class="classname">PartData</tt>, <tt class="classname">SupplierData</tt> and <tt class="classname">ShipmentData</tt> classes have been removed in this example, and the <tt class="classname">Part</tt>, <tt class="classname">Supplier</tt> and <tt class="classname">Shipment</tt> entity classes are used in their place. </p> <p> The serial formats are created with the entity classes. </p> <a id="sentity_sampledatabase"></a> <pre class="programlisting">public class SampleDatabase { ... public SampleDatabase(String homeDirectory) throws DatabaseException, FileNotFoundException { ... secConfig.setKeyCreator(new SupplierByCityKeyCreator(javaCatalog, <b class="userinput"><tt>Supplier</tt></b>.class)); ... secConfig.setKeyCreator(new ShipmentByPartKeyCreator(javaCatalog, <b class="userinput"><tt>Shipment</tt></b>.class)); ... secConfig.setKeyCreator(new ShipmentBySupplierKeyCreator(javaCatalog, <b class="userinput"><tt>Shipment</tt></b>.class)); ... } } </pre> <p> The index key creator uses the entity class as well. </p> <a id="sentity_supplierbycitykeycreator"></a> <pre class="programlisting">public class SampleDatabase { ... private static class SupplierByCityKeyCreator extends TupleSerialKeyCreator { private SupplierByCityKeyCreator(ClassCatalog catalog, Class valueClass) { super(catalog, valueClass); } public boolean createSecondaryKey(TupleInput primaryKeyInput, Object valueInput, TupleOutput indexKeyOutput) { <b class="userinput"><tt>Supplier</tt></b> supplier = (<b class="userinput"><tt>Supplier</tt></b>) valueInput; String city = supplier.getCity(); if (city != null) { indexKeyOutput.writeString(supplier.getCity()); return true; } else { return false; } } } } </pre> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="transientfieldsinbinding.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="SerializableEntity.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="Summary.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top"> Using Transient Fields in an Entity Binding </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Chapter 7. Summary </td> </tr> </table> </div> </body> </html>
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