conditional mapping and polish
This commit is contained in:
Keith Donald
parent
f63c3d5313
commit
3c4596a424
|
|
@ -1513,14 +1513,14 @@ public class PersonDtoPersonMapper implements Mapper<PersonDto, Person> {
|
|||
<title>General-purpose SpelMapper Implementation</title>
|
||||
<para>
|
||||
A general purpose object-to-object mapping system exists in the <classname>org.springframework.mapping.support</classname> package.
|
||||
Built on the flexible Spring Expression Language (SpEL), this system is capable of mapping between a variety of object types, including JavaBeans, Arrays, Collections, and Maps.
|
||||
It can perform field-to-field, field-to-multi-field, and multi-field to field mappings.
|
||||
It also can carry out type conversion and recursive mapping, often needed with rich object models.
|
||||
Built on the Spring Expression Language (SpEL), this system is capable of mapping between a variety of object types, including JavaBeans, Arrays, Collections, and Maps.
|
||||
It can perform field-to-field, field-to-multi-field, multi-field to field, and conditional mappings.
|
||||
It also can carry out type conversion and recursive mapping, which are often required with rich object models.
|
||||
</para>
|
||||
<section id="mapping.SpelMapper-usage">
|
||||
<title>Usage</title>
|
||||
<para>
|
||||
To obtain a general purpose object Mapper with its default configuration, simply call MappingFactory.getDefaultMapper().
|
||||
To obtain a general purpose object Mapper with its default configuration, simply call <methodname>MappingFactory.getDefaultMapper()</methodname>.
|
||||
Then invoke the Mapper by calling its <literal>map(Object, Object)</literal> operation:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[
|
||||
|
|
@ -1599,7 +1599,7 @@ public void testDefaultSpelMappingBehavior() {
|
|||
<title>Registering Explicit Mappings</title>
|
||||
<para>
|
||||
When default mapping rules are not sufficient, explicit mapping rules can be registered by obtaining a <classname>MapperBuilder</classname> and using it to construct a <classname>Mapper</classname>.
|
||||
Explicit mapping rules always override the default.
|
||||
Explicit mapping rules always override the default rule.
|
||||
The MapperBuilder provides a fluent API for registering object-to-object Mapping rules:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[
|
||||
|
|
@ -1614,8 +1614,8 @@ Mapper<PersonDto, Person> mapper =
|
|||
<title>Mapping between two fields with different names</title>
|
||||
<para>
|
||||
Suppose you need to map <literal>AccountDto.name</literal> to <literal>Account.fullName</literal>.
|
||||
Since the two property names are not the same, default auto-mapping would never be performed.
|
||||
Handle a situation like this by explicitly registering a mapping rule:
|
||||
Since these two field names are not the same, the default auto-mapping rule would not apply.
|
||||
Handle a requirement like this by explicitly registering a mapping rule:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[
|
||||
builder.addMapping("name", "fullName")]]>
|
||||
|
|
@ -1626,7 +1626,7 @@ builder.addMapping("name", "fullName")]]>
|
|||
</para>
|
||||
</section>
|
||||
<section id="mapping.SpelMapper-Explicit-singleFieldToMultipleField">
|
||||
<title>Mapping a single field value to multiple fields</title>
|
||||
<title>Mapping a single field to multiple fields</title>
|
||||
<para>
|
||||
Suppose you need to map <literal>PersonDto.name</literal> to <literal>Person.firstName</literal> and <literal>Person.lastName</literal>.
|
||||
Handle a field-to-multi-field requirement like this by explicitly registering a mapping rule:
|
||||
|
|
@ -1647,7 +1647,7 @@ builder.addMapping("name", new Mapper<String, Person>() {
|
|||
</para>
|
||||
</section>
|
||||
<section id="mapping.SpelMapper-Explicit-multipleFieldsToField">
|
||||
<title>Mapping a single field value to multiple fields</title>
|
||||
<title>Mapping multiple fields to a single field</title>
|
||||
<para>
|
||||
Suppose you need to map <literal>CreateAccountDto.activationDay</literal> and <literal>CreateAccountDto.activationTime</literal> to <literal>Account.activationDateTime</literal>.
|
||||
Handle a multi-field-to-field requirement like this by explicitly registering a mapping rule:
|
||||
|
|
@ -1664,7 +1664,22 @@ builder.addMapping(new String[] { "activationDay", "activationTime" }, new Mappe
|
|||
</programlisting>
|
||||
<para>
|
||||
In the example above, the <literal>activationDay</literal> and <literal>activationTime</literal> fields are mapped to the single <literal>activationDateTime</literal> field.
|
||||
No default mapping is performed for <literal>activationDay</literal> and <literal>activationTime</literal> since an explicit mapping rule has been configured for these fields.
|
||||
No default mapping is performed for <literal>activationDay</literal> or <literal>activationTime</literal> since an explicit mapping rule has been configured for these fields.
|
||||
</para>
|
||||
</section>
|
||||
<section id="mapping.SpelMapper-Explicit-conditionalMappings">
|
||||
<title>Mapping conditionally</title>
|
||||
<para>
|
||||
Suppose you need to map <literal>Map.countryCode</literal> to <literal>PhoneNumber.countryCode</literal> only if the source Map contains a international phone number.
|
||||
Handle conditional mapping requirements like this by explicitly registering a mapping rule:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[
|
||||
builder.addConditionalMapping("countryCode", "international == 'true'");]]>
|
||||
</programlisting>
|
||||
<para>
|
||||
In the example above, the <literal>countryCode</literal> field will only be mapped if the international field is 'true'.
|
||||
<literal>international == 'true'</literal> is a boolean expression that must evaluate to true for the mapping to be executed.
|
||||
No default mapping is performed for <literal>countryCode</literal> since an explicit mapping rule has been configured for this field.
|
||||
</para>
|
||||
</section>
|
||||
<section id="mapping.SpelMapper-Explicit-forcing">
|
||||
|
|
@ -1698,12 +1713,14 @@ builder.addMapping("name", "fullName").setConverter() { new Converter<String, St
|
|||
Sometimes you need to exclude a specific field on a source object from being mapped.
|
||||
Do this by marking one or more source fields as excluded:
|
||||
</para>
|
||||
<programlisting language="java">builder.setExcludedFields("name");</programlisting>
|
||||
<programlisting language="java"><![CDATA[
|
||||
builder.setExcludedFields("name");]]>
|
||||
</programlisting>
|
||||
</section>
|
||||
<section id="mapper.SpelMapper-CustomTypeConverters">
|
||||
<title>Registering Custom Type Converters</title>
|
||||
<para>
|
||||
You may also install Converters to convert values of different types in a custom way:
|
||||
You may also register custom Converters to convert values between mapped field of different types:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[
|
||||
builder.addConverter(new Converter<String, Date>() {
|
||||
|
|
@ -1748,5 +1765,4 @@ builder.addNestedMapper(new Mapper<AddressDto, Address>() {
|
|||
</para>
|
||||
</section>
|
||||
</section>
|
||||
|
||||
</chapter>
|
||||
Loading…
Reference in New Issue