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 <div class="refsect1">
 <h2 class="refsect1"><font face="arial, helvetica, sans-serif" color="#330099">@WriteTransformer</font></h2>
 <p>Use <code>@WriteTransformer</code> on a <code>TranformationMapping</code> to transform a single attribute value to a single database column value. Use the <code>@WriteTransformers</code> annotation to wrap multiple transformations.</p>
 <a id="sthref451" name="sthref451"></a>
 <p><strong><br /><span class="refsubsect">Annotation Elements</span></strong></p>
 <p><a href="#BGBEGIEE">Table 2-80</a> describes this annotation's elements.</p>
 <div class="tblhruleformalwide"><a id="TLJPA600" name="TLJPA600"></a><a id="sthref452" name="sthref452"></a><a id="BGBEGIEE" name="BGBEGIEE"></a>
 <p><strong><em><font face="arial, helvetica, sans-serif">Table 2-80 @WriteTransformer Annotation Elements</font></em></strong></p>
 <table class="HRuleFormalWide" title="@WriteTransformer Annotation Elements" summary="This table describes this annotation&rsquo;s elements." dir="ltr" border="1" width="100%" frame="hsides" rules="rows" cellpadding="3" cellspacing="0">
 <col width="19%" />
 <col width="*" />
 <col width="29%" />
 <thead>
 <tr align="left" valign="top">
 <th align="left" valign="bottom" id="r1c1-t97"><font face="Arial, Helvetica, sans-serif"><strong>Annotation Element</strong></font></th>
 <th align="left" valign="bottom" id="r1c2-t97"><font face="Arial, Helvetica, sans-serif"><strong>Description</strong></font></th>
 <th align="left" valign="bottom" id="r1c3-t97"><font face="Arial, Helvetica, sans-serif"><strong>Default</strong></font></th>
 </tr>
 </thead>
 <tbody>
 <tr align="left" valign="top">
 <td align="left" id="r2c1-t97" headers="r1c1-t97">
 <p><code>column</code></p>
 </td>
 <td align="left" headers="r2c1-t97 r1c2-t97">
 <p>(Optional) The column into which the value should be written.</p>
 <p>If a single <code>WriteTransfomer</code> annotates an attribute, the attribute's name will be used as the column name.</p>
 </td>
 <td align="left" headers="r2c1-t97 r1c3-t97">
 <p><code>@javax.persistence.Column</code></p>
 </td>
 </tr>
 <tr align="left" valign="top">
 <td align="left" id="r3c1-t97" headers="r1c1-t97">
 <p><code>method</code></p>
 </td>
 <td align="left" headers="r3c1-t97 r1c2-t97">
 <p>(Optional) The <code>String</code> method name that the mapped class must have. This method returns the value to be written into the database column.</p>
 <p><strong>Note</strong>: To support DDL generation and returning policy, the method should be defined to return a particular type, not just an <code>Object</code>. For example:<br />
 <code>public Time getStartTime()</code></p>
 <p>The method may require <code>@Transient</code> to avoid being mapped as a <code>Basic</code> by default.</p>
 </td>
 <td align="left" headers="r3c1-t97 r1c3-t97"><br /></td>
 </tr>
 <tr align="left" valign="top">
 <td align="left" id="r4c1-t97" headers="r1c1-t97">
 <p><code>transformerClass</code></p>
 </td>
 <td align="left" headers="r4c1-t97 r1c2-t97">
 <p>(Optional) User-defined class that implements the <code>FieldTransformer</code> interface. This will instantiate the class and use its <code>buildFieldValue</code> method to create the value to be written into the database column.</p>
 <p><strong>Note</strong>: To support DDL generation and returningpolicy, the method <code>buildFieldValue</code> in the class should be defined to return the relevant Java type, not just <code>Object</code> as defined in the interface. For example:<br />
 <code>public Time buildFieldValue(Object instance, String fieldName, Session session).</code></p>
 </td>
 <td align="left" headers="r4c1-t97 r1c3-t97">
 <p><code>void.class</code></p>
 </td>
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 <p class="note"><img src="../../../dcommon/images/note_icon.png" width="16" height="16" alt="Note" style="vertical-align:middle;padding-right:5px;" />Note:</p>
 <p>You must specify either <code>transformerClass</code> <em>or</em> <code>method</code> , but not both.</p>
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 <a id="sthref453" name="sthref453"></a>
 <p><strong><br /><span class="refsubsect">Usage</span></strong></p>
 <p>You cannot define a <code>@WriteTransforme</code>r for a read-only mapping.</p>
 <p>Unless the <code>TransformationMapping</code> is write-only, it should include a <code>ReadTransformer</code> that defines the transformation of the database column values into attribute values.</p>
 <a id="sthref454" name="sthref454"></a>
 <p><strong><font face="arial, helvetica, sans-serif" color="#330099">Configuring Field Transformer Associations</font></strong></p>
 <p>Using a <code>FieldTransformer</code> is non-intrusive; your domain object does not need to implement an EclipseLink interface or provide a special transformation method.</p>
 <p>You can configure a method-based field transformer using <code>AbstractTransformationMapping</code> method <code>addFieldTransformation</code>, passing in the name of the database field and the name of the domain object method to use.</p>
 <p>You can configure a class-based field transformer using <code>AbstractTransformationMapping</code> method <code>addFieldTransformer</code>, passing in the name of the database field and an instance of <code>org.eclipse.persistence.mappings.Transfomers.FieldTransformer</code>.</p>
 <p>A convenient way to create a <code>FieldTransformer</code> is to extend <code>FieldTransformerAdapter</code>.</p>
 <a id="sthref455" name="sthref455"></a>
 <p><strong><br /><span class="refsubsect">Examples</span></strong></p>
 <p>See <a href="a_transformation.htm#BABHECGF">"Using @Transformation Annotation"</a> for an example of how to use the <code>@WriteTransformer annotation</code> with a Transformation mapping.</p>
 <a id="sthref456" name="sthref456"></a>
 <p><strong><br /><span class="refsubsect">See Also</span></strong></p>
 <p>For more information, see:</p>
 <ul>
 <li>
 <p><a href="a_writetransformers.htm#BCFCCEJF">"@WriteTransformers"</a></p>
 </li>
 <li>
 <p><a href="a_transformation.htm#BABCJGIG">"@Transformation"</a>.</p>
 </li>
 <li>
 <p>http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Print_Version#How_to_Use_the_.40Transformation_Annotation</p>
 </li>
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	<div class="refsect1">
	<h2 class="refsect1"><font face="arial, helvetica, sans-serif" color="#330099">@WriteTransformer</font></h2>
	<p>Use <code>@WriteTransformer</code> on a <code>TranformationMapping</code> to transform a single attribute value to a single database column value. Use the <code>@WriteTransformers</code> annotation to wrap multiple transformations.</p>
	<a id="sthref451" name="sthref451"></a>
	<p><strong><br /><span class="refsubsect">Annotation Elements</span></strong></p>
	<p><a href="#BGBEGIEE">Table 2-80</a> describes this annotation's elements.</p>
	<div class="tblhruleformalwide"><a id="TLJPA600" name="TLJPA600"></a><a id="sthref452" name="sthref452"></a><a id="BGBEGIEE" name="BGBEGIEE"></a>
	<p><strong><em><font face="arial, helvetica, sans-serif">Table 2-80 @WriteTransformer Annotation Elements</font></em></strong></p>
	<table class="HRuleFormalWide" title="@WriteTransformer Annotation Elements" summary="This table describes this annotation’s elements." dir="ltr" border="1" width="100%" frame="hsides" rules="rows" cellpadding="3" cellspacing="0">
	<col width="19%" />
	<col width="*" />
	<col width="29%" />
	<thead>
	<tr align="left" valign="top">
	<th align="left" valign="bottom" id="r1c1-t97"><font face="Arial, Helvetica, sans-serif"><strong>Annotation Element</strong></font></th>
	<th align="left" valign="bottom" id="r1c2-t97"><font face="Arial, Helvetica, sans-serif"><strong>Description</strong></font></th>
	<th align="left" valign="bottom" id="r1c3-t97"><font face="Arial, Helvetica, sans-serif"><strong>Default</strong></font></th>
	</tr>
	</thead>
	<tbody>
	<tr align="left" valign="top">
	<td align="left" id="r2c1-t97" headers="r1c1-t97">
	<p><code>column</code></p>
	</td>
	<td align="left" headers="r2c1-t97 r1c2-t97">
	<p>(Optional) The column into which the value should be written.</p>
	<p>If a single <code>WriteTransfomer</code> annotates an attribute, the attribute's name will be used as the column name.</p>
	</td>
	<td align="left" headers="r2c1-t97 r1c3-t97">
	<p><code>@javax.persistence.Column</code></p>
	</td>
	</tr>
	<tr align="left" valign="top">
	<td align="left" id="r3c1-t97" headers="r1c1-t97">
	<p><code>method</code></p>
	</td>
	<td align="left" headers="r3c1-t97 r1c2-t97">
	<p>(Optional) The <code>String</code> method name that the mapped class must have. This method returns the value to be written into the database column.</p>
	<p><strong>Note</strong>: To support DDL generation and returning policy, the method should be defined to return a particular type, not just an <code>Object</code>. For example:<br />
	<code>public Time getStartTime()</code></p>
	<p>The method may require <code>@Transient</code> to avoid being mapped as a <code>Basic</code> by default.</p>
	</td>
	<td align="left" headers="r3c1-t97 r1c3-t97"><br /></td>
	</tr>
	<tr align="left" valign="top">
	<td align="left" id="r4c1-t97" headers="r1c1-t97">
	<p><code>transformerClass</code></p>
	</td>
	<td align="left" headers="r4c1-t97 r1c2-t97">
	<p>(Optional) User-defined class that implements the <code>FieldTransformer</code> interface. This will instantiate the class and use its <code>buildFieldValue</code> method to create the value to be written into the database column.</p>
	<p><strong>Note</strong>: To support DDL generation and returningpolicy, the method <code>buildFieldValue</code> in the class should be defined to return the relevant Java type, not just <code>Object</code> as defined in the interface. For example:<br />
	<code>public Time buildFieldValue(Object instance, String fieldName, Session session).</code></p>
	</td>
	<td align="left" headers="r4c1-t97 r1c3-t97">
	<p><code>void.class</code></p>
	</td>
	</tr>
	</tbody>
	</table>
	<br /></div>
	<!-- class="tblhruleformalwide" -->
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	<table class="Note oac_no_warn" summary="" border="1" width="80%" frame="hsides" rules="groups" cellpadding="3" cellspacing="0">
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	<tr>
	<td align="left">
	<p class="note"><img src="../../../dcommon/images/note_icon.png" width="16" height="16" alt="Note" style="vertical-align:middle;padding-right:5px;" />Note:</p>
	<p>You must specify either <code>transformerClass</code> <em>or</em> <code>method</code> , but not both.</p>
	</td>
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	<a id="sthref453" name="sthref453"></a>
	<p><strong><br /><span class="refsubsect">Usage</span></strong></p>
	<p>You cannot define a <code>@WriteTransforme</code>r for a read-only mapping.</p>
	<p>Unless the <code>TransformationMapping</code> is write-only, it should include a <code>ReadTransformer</code> that defines the transformation of the database column values into attribute values.</p>
	<a id="sthref454" name="sthref454"></a>
	<p><strong><font face="arial, helvetica, sans-serif" color="#330099">Configuring Field Transformer Associations</font></strong></p>
	<p>Using a <code>FieldTransformer</code> is non-intrusive; your domain object does not need to implement an EclipseLink interface or provide a special transformation method.</p>
	<p>You can configure a method-based field transformer using <code>AbstractTransformationMapping</code> method <code>addFieldTransformation</code>, passing in the name of the database field and the name of the domain object method to use.</p>
	<p>You can configure a class-based field transformer using <code>AbstractTransformationMapping</code> method <code>addFieldTransformer</code>, passing in the name of the database field and an instance of <code>org.eclipse.persistence.mappings.Transfomers.FieldTransformer</code>.</p>
	<p>A convenient way to create a <code>FieldTransformer</code> is to extend <code>FieldTransformerAdapter</code>.</p>
	<a id="sthref455" name="sthref455"></a>
	<p><strong><br /><span class="refsubsect">Examples</span></strong></p>
	<p>See <a href="a_transformation.htm#BABHECGF">"Using @Transformation Annotation"</a> for an example of how to use the <code>@WriteTransformer annotation</code> with a Transformation mapping.</p>
	<a id="sthref456" name="sthref456"></a>
	<p><strong><br /><span class="refsubsect">See Also</span></strong></p>
	<p>For more information, see:</p>
	<ul>
	<li>
	<p><a href="a_writetransformers.htm#BCFCCEJF">"@WriteTransformers"</a></p>
	</li>
	<li>
	<p><a href="a_transformation.htm#BABCJGIG">"@Transformation"</a>.</p>
	</li>
	<li>
	<p>http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Print_Version#How_to_Use_the_.40Transformation_Annotation</p>
	</li>
	</ul>
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