<?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>Using Transient Fields in an Entity Binding</title> <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB Collections Tutorial" /> <link rel="up" href="SerializableEntity.html" title="Chapter 6. Using Serializable Entities" /> <link rel="prev" href="SerializableEntity.html" title="Chapter 6. Using Serializable Entities" /> <link rel="next" href="removingredundantvalueclasses.html" title="Removing the Redundant Value Classes" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center"> Using Transient Fields in an Entity Binding </th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="SerializableEntity.html">Prev</a> </td> <th width="60%" align="center">Chapter 6. Using Serializable Entities </th> <td width="20%" align="right"> <a accesskey="n" href="removingredundantvalueclasses.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="transientfieldsinbinding"></a> Using Transient Fields in an Entity Binding </h2> </div> </div> </div> <p> The entity bindings from the prior example have been changed in this example to use the entity object both as a value object and an entity object. </p> <p> Before, the <code class="methodname">entryToObject()</code> method combined the deserialized value object with the key fields to create a new entity object. Now, this method uses the deserialized object directly as an entity, and initializes its key using the fields read from the key tuple. </p> <p> Before, the <code class="methodname">objectToData()</code> method constructed a new value object using information in the entity. Now it simply returns the entity. Nothing needs to be changed in the entity, since the transient key fields won't be serialized. </p> <a id="sentity_partbinding"></a> <pre class="programlisting">import com.sleepycat.bind.serial.ClassCatalog; ... public class SampleViews { ... private static class PartBinding extends TupleSerialBinding { private PartBinding(ClassCatalog classCatalog, Class dataClass) { super(classCatalog, dataClass); } public Object entryToObject(TupleInput keyInput, Object dataInput) { String number = keyInput.readString(); <strong class="userinput"><code> Part part = (Part) dataInput; part.setKey(number); return part;</code></strong> } public void objectToKey(Object object, TupleOutput output) { Part part = (Part) object; output.writeString(part.getNumber()); } public Object objectToData(Object object) { <strong class="userinput"><code> return object;</code></strong> } } private static class SupplierBinding extends TupleSerialBinding { private SupplierBinding(ClassCatalog classCatalog, Class dataClass) { super(classCatalog, dataClass); } public Object entryToObject(TupleInput keyInput, Object dataInput) { String number = keyInput.readString(); <strong class="userinput"><code> Supplier supplier = (Supplier) dataInput; supplier.setKey(number); return supplier;</code></strong> } public void objectToKey(Object object, TupleOutput output) { Supplier supplier = (Supplier) object; output.writeString(supplier.getNumber()); } public Object objectToData(Object object) { <strong class="userinput"><code> return object;</code></strong> } } private static class ShipmentBinding extends TupleSerialBinding { private ShipmentBinding(ClassCatalog classCatalog, Class dataClass) { super(classCatalog, dataClass); } public Object entryToObject(TupleInput keyInput, Object dataInput) { String partNumber = keyInput.readString(); String supplierNumber = keyInput.readString(); <strong class="userinput"><code> Shipment shipment = (Shipment) dataInput; shipment.setKey(partNumber, supplierNumber); return shipment;</code></strong> } public void objectToKey(Object object, TupleOutput output) { Shipment shipment = (Shipment) object; output.writeString(shipment.getPartNumber()); output.writeString(shipment.getSupplierNumber()); } public Object objectToData(Object object) { <strong class="userinput"><code> return object;</code></strong> } } } </pre> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="SerializableEntity.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="removingredundantvalueclasses.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Chapter 6. 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