我可以使用 MapStruct 控制映射顺序吗？

Question

我有一个用例，我想将对象映射到 ByteBuffer 进行传输......

    @Mapper
    public static interface ByteBufferMapper {
        public static ByteBufferMapper INSTANCE = Mappers.getMapper(ByteBufferMapper.class);

        default byte toByte(ByteBuffer buffer) {
            byte b = buffer.get();
            return b;
        }
    }

    public static class Dto {
        public byte b;
        public byte bb;
        ...
    }

    @Mapper(uses = ByteBufferMapper.class)
    public static interface DtoMapper {
        public static DtoMapper INSTANCE = Mappers.getMapper(DtoMapper.class);

        @Mapping(source = "buffer", target = "bb")
        @Mapping(source = "buffer", target = "b")
        Dto byteBufferToDto(ByteBuffer buffer);
    }

    public static void main( String[] args ) {
        ByteBuffer buffer = ByteBuffer.allocate(2).put((byte) 0xFF).put((byte) 0x00).flip();
        System.out.println(DtoMapper.INSTANCE.byteBufferToDto(buffer));
    }

有没有办法可以控制 MapStructs 映射顺序，以便b变量填充 0xFF 并bb填充 0x00 值？

Answer 1

是的，您可以通过@Mapping.dependsOn.

像这样：

    @Mappings({
        @Mapping(target = "surName", source = "lastName", dependsOn = "middleName"),
        @Mapping(target = "middleName", dependsOn = "givenName"),
        @Mapping(target = "givenName", source = "firstName")
    })
    AddressDto addressToDto(Address address);