1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title> 7 Using Transient Fields in an Entity Binding 8 </title> 9 <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> 10 <meta name="generator" content="DocBook XSL Stylesheets V1.62.4" /> 11 <link rel="home" href="index.html" title="Berkeley DB Collections Tutorial" /> 12 <link rel="up" href="SerializableEntity.html" title="Chapter��6.�� 		Using Serializable Entities 	" /> 13 <link rel="previous" href="SerializableEntity.html" title="Chapter��6.�� 		Using Serializable Entities 	" /> 14 <link rel="next" href="removingredundantvalueclasses.html" title=" 		Removing the Redundant Value Classes 	" /> 15 </head> 16 <body> 17 <div class="navheader"> 18 <table width="100%" summary="Navigation header"> 19 <tr> 20 <th colspan="3" align="center"> 21 Using Transient Fields in an Entity Binding 22 </th> 23 </tr> 24 <tr> 25 <td width="20%" align="left"><a accesskey="p" href="SerializableEntity.html">Prev</a>��</td> 26 <th width="60%" align="center">Chapter��6.�� 27 Using Serializable Entities 28 </th> 29 <td width="20%" align="right">��<a accesskey="n" href="removingredundantvalueclasses.html">Next</a></td> 30 </tr> 31 </table> 32 <hr /> 33 </div> 34 <div class="sect1" lang="en" xml:lang="en"> 35 <div class="titlepage"> 36 <div> 37 <div> 38 <h2 class="title" style="clear: both"><a id="transientfieldsinbinding"></a> 39 Using Transient Fields in an Entity Binding 40 </h2> 41 </div> 42 </div> 43 <div></div> 44 </div> 45 <p> 46 The entity bindings from the prior example have been changed in 47 this example to use the entity object both as a value object and an 48 entity object. 49</p> 50 <p> 51 Before, the <tt class="methodname">entryToObject()</tt> method combined the 52 deserialized value object with the key fields to create a new 53 entity object. Now, this method uses the deserialized object 54 directly as an entity, and initializes its key using the fields 55 read from the key tuple. 56</p> 57 <p> 58 Before, the <tt class="methodname">objectToData()</tt> method constructed a new value 59 object using information in the entity. Now it simply returns the 60 entity. Nothing needs to be changed in the entity, since the 61 transient key fields won't be serialized. 62</p> 63 <a id="sentity_partbinding"></a> 64 <pre class="programlisting">import com.sleepycat.bind.serial.ClassCatalog; 65... 66public class SampleViews 67{ 68 ... 69 private static class PartBinding extends TupleSerialBinding 70 { 71 private PartBinding(ClassCatalog classCatalog, Class dataClass) 72 { 73 super(classCatalog, dataClass); 74 } 75 76 public Object entryToObject(TupleInput keyInput, Object dataInput) 77 { 78 String number = keyInput.readString(); 79<b class="userinput"><tt> Part part = (Part) dataInput; 80 part.setKey(number); 81 return part;</tt></b> 82 } 83 84 public void objectToKey(Object object, TupleOutput output) 85 { 86 Part part = (Part) object; 87 output.writeString(part.getNumber()); 88 } 89 90 public Object objectToData(Object object) 91 { 92<b class="userinput"><tt> return object;</tt></b> 93 } 94 } 95 96 private static class SupplierBinding extends TupleSerialBinding 97 { 98 private SupplierBinding(ClassCatalog classCatalog, Class dataClass) 99 { 100 super(classCatalog, dataClass); 101 } 102 103 public Object entryToObject(TupleInput keyInput, Object dataInput) 104 { 105 String number = keyInput.readString(); 106<b class="userinput"><tt> Supplier supplier = (Supplier) dataInput; 107 supplier.setKey(number); 108 return supplier;</tt></b> 109 } 110 111 public void objectToKey(Object object, TupleOutput output) 112 { 113 Supplier supplier = (Supplier) object; 114 output.writeString(supplier.getNumber()); 115 } 116 117 public Object objectToData(Object object) 118 { 119<b class="userinput"><tt> return object;</tt></b> 120 } 121 } 122 123 private static class ShipmentBinding extends TupleSerialBinding 124 { 125 private ShipmentBinding(ClassCatalog classCatalog, Class dataClass) 126 { 127 super(classCatalog, dataClass); 128 } 129 130 public Object entryToObject(TupleInput keyInput, Object dataInput) 131 { 132 String partNumber = keyInput.readString(); 133 String supplierNumber = keyInput.readString(); 134<b class="userinput"><tt> Shipment shipment = (Shipment) dataInput; 135 shipment.setKey(partNumber, supplierNumber); 136 return shipment;</tt></b> 137 } 138 139 public void objectToKey(Object object, TupleOutput output) 140 { 141 Shipment shipment = (Shipment) object; 142 output.writeString(shipment.getPartNumber()); 143 output.writeString(shipment.getSupplierNumber()); 144 } 145 146 public Object objectToData(Object object) 147 { 148<b class="userinput"><tt> return object;</tt></b> 149 } 150 } 151} </pre> 152 </div> 153 <div class="navfooter"> 154 <hr /> 155 <table width="100%" summary="Navigation footer"> 156 <tr> 157 <td width="40%" align="left"><a accesskey="p" href="SerializableEntity.html">Prev</a>��</td> 158 <td width="20%" align="center"> 159 <a accesskey="u" href="SerializableEntity.html">Up</a> 160 </td> 161 <td width="40%" align="right">��<a accesskey="n" href="removingredundantvalueclasses.html">Next</a></td> 162 </tr> 163 <tr> 164 <td width="40%" align="left" valign="top">Chapter��6.�� 165 Using Serializable Entities 166 ��</td> 167 <td width="20%" align="center"> 168 <a accesskey="h" href="index.html">Home</a> 169 </td> 170 <td width="40%" align="right" valign="top">�� 171 Removing the Redundant Value Classes 172 </td> 173 </tr> 174 </table> 175 </div> 176 </body> 177</html> 178