CODEWITHSUNDEEP
javamapstruct
JimmyD
JimmyD

Reputation: 2759

Map custom method mapper to Mapstruct

I'm creating a poc for using Mapstruct in my future projects.

Now I have one question how to map custom methods to a special target.

For example I have following interface mapper:

@Mapper
public interface ItemMapper {

    static ItemMapper INSTANCE = Mappers.getMapper(ItemMapper.class);

    @Mappings({ @Mapping(source = "number", target = "itemnumber"),
            @Mapping(source = "description", target = "description"),
            @Mapping(source = "itemClass.name", target = "ic"), @Mapping(source = "optionPart", target = "option"),
            @Mapping(source = "plannerCode.code", target = "plannercode"),
            @Mapping(source = "plannerCode.name", target = "planner"),
            @Mapping(source = "vendor.buyerCode.name", target = "buyer"),
            @Mapping(source = "vendor.buyerCode.code", target = "buyerCode"),
            @Mapping(source = "vendor.number", target = "vendor"),
            @Mapping(source = "vendor.name", target = "vendorName"), @Mapping(source = "pcsItem", target = "pcs"),
            @Mapping(source = "specialColourVariant", target = "specialColors"),
            @Mapping(source = "qtyBufferGreen", target = "greenLine"),
            @Mapping(source = "qtyBufferRed", target = "redine"), @Mapping(source = "leadtime", target = "leadTime"),
            @Mapping(source = "qtyStock", target = "stockAC"),
            @Mapping(source = "qtyStockSupplier", target = "stockSupplier"),
            @Mapping(source = "qtyPurchaseOrder", target = "qtyPo"),
            @Mapping(source = "qtyShopOrder", target = "qtySo"),
            @Mapping(source = "qtyFirmPlannedOrder", target = "qtyFpo"),
            @Mapping(source = "qtyForecast", target = "qtyForecast"),
            @Mapping(source = "standardCost", target = "stdCost"),
            @Mapping(source = "itemCategory.name", target = "category") })
    ItemViewModel itemToDto(Item item);

    default String locationToLocationDto(Item item) {
        return item.getItemsOnDetailedLocations().iterator().next().getLocation().getLocation();
    }

    default double locationToBinType(Item item) {
        return item.getItemsOnDetailedLocations().iterator().next().getBinType();
    }

    default double itemToLotsize(Item item) {
        double lotSize = 0;
        if (item.getLotsize() != null) {
            lotSize = item.getLotsize();
        } else if (item.getItemsOnDetailedLocations() != null && !item.getItemsOnDetailedLocations().isEmpty()) {
            ItemsOnDetailedLocation location = item.getItemsOnDetailedLocations().iterator().next();
            lotSize = location.getLotSize();
        } else {
            lotSize = 0.0;
        }
        return lotSize;
    }

    default double stockRails(Item item) {
        double value = 0;
        for (ItemsOnDetailedLocation detailedLocation : item.getItemsOnDetailedLocations()) {

            if (detailedLocation.getId().getSource().equals("RAILS")) {

                long lotSize2 = detailedLocation.getLotSize();
                long binInStock = detailedLocation.getBinInStock();

                if (binInStock != 0) {

                    value += lotSize2 * (binInStock - 0.5);
                }
            }

        }

        return value;
    }

}

In the code you can see the mapping and some default methods with other mapping in it. How can I use those methods in the Mapstruct mappings so that mapstruct uses those methods to fillin values in the fields?

Upvotes: 57

Views: 164374

Answers (4)

Grigory Kislin
Grigory Kislin

Reputation: 17990

The simplest way is to use the powerful MapStruct @AfterMapping annotation. E.g.

@AfterMapping
public void treatAdditional(User user, @MappingTarget StudentSkillsTo studentSkillsTo) {
    System.out.println("After mapping!");
}

Upvotes: 21

Filip
Filip

Reputation: 21393

As you have multiple default methods that return the same type. You would need to use Mapping method selection based on qualifiers.

What this means is that you would need to write your mapper in the following format:

@Mapper
public interface ItemMapper {

    // Omitting other mappings for clarity
    @Mapping(source = "item", target = "locationDto", qualifiedByName = "locationDto")
    @Mapping(source = "item", target = "binType", qualifiedByName = "binType")
    @Mapping(source = "item", target = "lotSize", qualifiedByName = "lotSize")
    @Mapping(source = "item", target = "stockRails", qualifiedByName = "stockRails")
    ItemViewModel itemToDto(Item item);

    @Named("locationDto")
    default String locationToLocationDto(Item item) {
        //Omitting implementation
    }

    @Named("binType")
    default double locationToBinType(Item item) {
        //Omitting implementation
    }

    @Named("lotSize")
    default double itemToLotsize(Item item) {
        //Omitting implementation
    }

    @Named("stockRails")
    default double stockRails(Item item) {
        //Omitting implementation
    }
}

Some important notes:

  • You need to use @Named from the MapStruct package
  • In source you can also specify the name of the parameter of the method
  • In qualifiedByName you need to specify the value that you have written in @Named
  • It finds the method not only by the value of @Named but also by the parameter type and return type. If it gives a compilation error that it cannot find the method by @Named it might be because the types of the parameter and the return value of the method do not fit the types of the target and the source of the @Mapping

I would strongly advise against using expressions for such complicated things. It is much more difficult to get it correct and it is more difficult for maintaining

Upvotes: 122

Naveen
Naveen

Reputation: 473

You can simply use them like following

@Mapping( target="/*Enter targetFieldName*/", expression="java( /default method which calculates target field/" )

Upvotes: 4

none
none

Reputation: 123

Mapstruct can use similar constructions:

@Mapping(target = "name", expression = "java(user.getName() != null " +
        " ? user.getName() : "DefaultName")")

an expression can include any constructions on java e.g

 item.getItemsOnDetailedLocations()
.iterator().next().getLocation().getLocation();

if the method is large, then it is worthwhile to take it to another service and call this way

Upvotes: 10

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