使用 Mapstruct 将多个源字段映射到相同类型的目标字段

Question

考虑以下 POJO：

public class SchedulePayload {
    public String name;
    public String scheduler;
    public PeriodPayload notificationPeriod;
    public PeriodPayload schedulePeriod;
}

private class Lecture {
    public ZonedDateTime start;
    public ZonedDateTime end;
}

public class XmlSchedule {
    public String scheduleName;
    public String schedulerName;
    public DateTime notificationFrom;
    public DateTime notificationTo;
    public DateTime scheduleFrom;
    public DateTime scheduleTo;
}

public class PeriodPayload {
    public DateTime start;
    public DateTime finish;
}

使用 MapStruct，我创建了一个映射器，将 XmlSchedule 映射到 SchedulePayload。由于“业务”“逻辑”，我需要将notificationPeriod 和schedulePeriod 限制为Lecture 的start 和end 字段值。这是我想出的，使用另一个类：

@Mapper(imports = { NotificationPeriodHelper.class })
public interface ISchedulePayloadMapper
{
    @Mappings({
        @Mapping(target = "name", source = "scheduleName"),
        @Mapping(target = "scheduler", source = "schedulerName"),
        @Mapping(target = "notificationPeriod", expression = "java(NotificationPeriodHelper.getConstrainedPeriod(xmlSchedule, notificationFrom, notificationTo))"),
        @Mapping(target = "schedulePeriod", expression = "java(NotificationPeriodHelper.getConstrainedPeriod(xmlSchedule, scheduleFrom, scheduleTo))")
    })
    SchedulePayload map(XmlSchedule xmlSchedule, Lecture lecture);

}

有什么方法可以通过其他方式实现（即另一个映射器、装饰器等）？如何将多个值（xmlSchedule、lecture）传递给映射器？

Answer 1

您可以做的是创建一个@AfterMapping 方法来手动填充这些部分：

@Mapper
public abstract class SchedulePayloadMapper
{
    @Mappings({
        @Mapping(target = "name", source = "scheduleName"),
        @Mapping(target = "scheduler", source = "schedulerName"),
        @Mapping(target = "notificationPeriod", expression = "java(NotificationPeriodHelper.getConstrainedPeriod(xmlSchedule, notificationFrom, notificationTo))"),
        @Mapping(target = "schedulePeriod", expression = "java(NotificationPeriodHelper.getConstrainedPeriod(xmlSchedule, scheduleFrom, scheduleTo))")
    })
    public abstract SchedulePayload map(XmlSchedule xmlSchedule, Lecture lecture);

    @AfterMapping
    protected void addPeriods(@MappingTarget SchedulePayload result, XmlSchedule xmlSchedule, Lecture lecture) {
        result.setNotificationPeriod(..);
        result.setSchedulePeriod(..);
    }
}

或者，您可以将 @AfterMapping 方法放在另一个在 @Mapper(uses = ..) 中引用的类中，或者您可以使用装饰器（使用 MapStruct 提供的机制，或者如果您使用依赖注入框架）。