org.mapstruct

Annotation Type IterableMapping

@Target(value=METHOD)
 @Retention(value=CLASS)
public @interface IterableMapping

Configures the mapping between two iterable like types, e.g. List<String> and List<Date>.

Note: either dateFormat(), elementTargetType() or qualifiedBy() must be specified

Example: Convert List<Float> to List<String>

 @Mapper
 public interface FloatToStringMapper {
      @IterableMapping( numberFormat = "##.00" )
      List<String> sourceToTarget(List<Float> source);
 }
 

 // generates
 public class FloatToStringMapperImpl implements FloatToStringMapper {
      @Override
      public List<String> sourceToTarget(List<Float> source) {
          List<String> list = new ArrayList<String>( source.size() );
          for ( Float float1 : source ) {
              list.add( new DecimalFormat( "##.00" ).format( float1 ) );
          }
     // ...
      }
 }
 

Supported mappings are:

• Iterable<A> to/from Iterable<B>/Iterable<A>
• Iterable<A> to/from B[]/A[]
• Iterable<A> to/from Stream<B>/Stream<A>
• A[] to/from Stream<B>/Stream<A>
• A[] to/from B[]
• Stream<A> to/from Stream<B>

Author:

Gunnar Morling

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	dateFormat A format string as processable by SimpleDateFormat if the annotated method maps from an iterable of String to an iterable Date or vice-versa.
Class<? extends Annotation>	elementMappingControl Allows detailed control over the mapping process.
Class<?>	elementTargetType Specifies the type of the element to be used in the result of the mapping method in case multiple mapping methods qualify.
NullValueMappingStrategy	nullValueMappingStrategy The strategy to be applied when null is passed as source value to this iterable mapping.
String	numberFormat A format string as processable by DecimalFormat if the annotated method maps from a Number to a String or vice-versa.
Class<? extends Annotation>[]	qualifiedBy A qualifier can be specified to aid the selection process of a suitable mapper.
String[]	qualifiedByName String-based form of qualifiers; When looking for a suitable mapping method to map this iterable mapping method's element type, MapStruct will only consider those methods carrying directly or indirectly (i.e. on the class-level) a Named annotation for each of the specified qualifier names.

Element Detail

dateFormat

public abstract String dateFormat

A format string as processable by SimpleDateFormat if the annotated method maps from an iterable of String to an iterable Date or vice-versa. Will be ignored for all other element types.

Returns:

A date format string as processable by SimpleDateFormat.

Default:

""

numberFormat

public abstract String numberFormat

A format string as processable by DecimalFormat if the annotated method maps from a Number to a String or vice-versa. Will be ignored for all other element types.

Returns:

A decimal format string as processable by DecimalFormat.

Default:

""

qualifiedBy

public abstract Class<? extends Annotation>[] qualifiedBy

A qualifier can be specified to aid the selection process of a suitable mapper. This is useful in case multiple mappers (hand written of internal) qualify and result in an 'Ambiguous mapping methods found' error. A qualifier is a custom annotation and can be placed on either a hand written mapper class or a method.

Returns:

the qualifiers

See Also:

Qualifier

Default:

{}

qualifiedByName

public abstract String[] qualifiedByName

String-based form of qualifiers; When looking for a suitable mapping method to map this iterable mapping method's element type, MapStruct will only consider those methods carrying directly or indirectly (i.e. on the class-level) a Named annotation for each of the specified qualifier names.

Note that annotation-based qualifiers are generally preferable as they allow more easily to find references and are safe for refactorings, but name-based qualifiers can be a less verbose alternative when requiring a large number of qualifiers as no custom annotation types are needed.

Returns:

One or more qualifier name(s)

See Also:

qualifiedBy(), Named

Default:

{}

elementTargetType

public abstract Class<?> elementTargetType

Specifies the type of the element to be used in the result of the mapping method in case multiple mapping methods qualify.

Returns:

the elementTargetType to select

Default:

void.class

nullValueMappingStrategy

public abstract NullValueMappingStrategy nullValueMappingStrategy

The strategy to be applied when null is passed as source value to this iterable mapping. If no strategy is configured, the strategy given via MapperConfig.nullValueMappingStrategy() or Mapper.nullValueMappingStrategy() will be applied, using NullValueMappingStrategy.RETURN_NULL by default.

Returns:

The strategy to be applied when null is passed as source value to the methods of this mapping.

Default:

org.mapstruct.NullValueMappingStrategy.RETURN_NULL

elementMappingControl

public abstract Class<? extends Annotation> elementMappingControl

Allows detailed control over the mapping process.

Returns:

the mapping control

Since:

1.4

See Also:

DeepClone, NoComplexMapping, MappingControl

Default:

org.mapstruct.control.MappingControl.class