CODEWITHSUNDEEP
javamapstruct
coffman21
coffman21

Reputation: 1063

Mapping fields to nested object using custom method

Say I have incoming object with fields like:

class IncomingRequest {
    // ... some fields ommited
    String amount;   // e.g. "1000.00"
    String currency; // e.g. "840"
}

There are more fields which converts great to my DTO:

class MyDto {
    // ... some fields which converts great ommited
    Amount amount;
}

class Amount {
    Long value;
    Integer exponent;
    Integer currency;
}

, but I want to map this two in custom way like:

@Mapper
public interface DtoMapper {

    @Mappings({ ... some mappings that works great ommited })
    MyDto convert(IncomingRequest request);

    @Mapping( /* what should I use here ? */ )
    default Amount createAmount(IncomingRequest request) {
        long value = ....
        int exponent = ....
        int currency = ....
        return new Amount(value, exponent, currency);
}

meaning I need to write a method to convert only a couple of IncomingRequest's fields to nested DTO object. How would I achieve that?

UPD: I wouldn't mind if only converted parameters will be passed to method:

default Amount createAmount(String amount, String currency) {
    ...
}

That would even be better.

Upvotes: 1

Views: 431

Answers (1)

Sjaak
Sjaak

Reputation: 4140

Well, there is a construct that maps method parameter like this:

@Mapper
public interface DtoMapper {

    @Mapping( target = "amount", source = "request" /* the param name */ )
    MyDto convert(IncomingRequest request);

    // @Mapping( /* what should I use here ? Answer: nothing its an implemented method.. @Mapping does not make sense */ )
    default Amount createAmount(IncomingRequest request) {
        long value = ....
        int exponent = ....
        int currency = ....
        return new Amount(value, exponent, currency);
}

Alternatively you could do aftermappings..

@Mapper
public interface DtoMapper {

    @Mapping( target = amount, ignore = true /* leave it to after mapping */ )
    MyDto convert(IncomingRequest request);

    @AfterMapping(  )
    default void createAmount(IncomingRequest request, @MappingTarget MyDto dto) {
        // which completes the stuff you cannot do
        dto.setAmount( new Amount(value, exponent, currency) );
}

Note: you could omit @Mappings in java8

Upvotes: 5

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