使用MapStruct进行嵌套列表映射

时间:2017-10-20 01:22:39

标签: mapstruct

如何使用MapStruct进行bean映射以实现以下方案。

class Source {
private String sourceId;
private List<Course> courses;  //always returns only one course
}

class Course {
private String courseName;
private List<Student> students; 
}

class Student {
private String studentName;
}

class Target {
private String targetId;
private String subjectName;
private List<Member> members;
}

class Member {
private String memberName;
}

现在我想将sourceId映射到targetId,将courseName映射到subjectName,将studentName映射到memberName(列表到列表)。

1 个答案:

答案 0 :(得分:3)

首先,Source始终包含一个课程,为什么不将其设为Course元素而不是List

如果你这样做,映射会更简单。对于您当前的设置,它有点复杂。

@Mapper
public interface MyMapper {

    @Mapping(target = "targetId", source = "sourceId")
    @Mapping(target = "subjectName", source = "courses")
    @Mapping(target = "members", source = "courses")
    Target map(Source source);

    default String subjectName(List<Course> courses) {
        if (courses == null || courses.isEmpty()) {
            return null;
        }
        return courses.get(0).getCourseName();
    }

    default List<Member> toMembersFromCourses(List<Course> courses) {
        if (courses == null || courses.isEmpty()) {
            return null;
        }
        return toMembers(courses.get(0).getStudents());
    }

    List<Member> toMembers(List<Student> students);

    @Mapping(target = "memberName", source = "studentName")
    Member toMember(Student student);
}

如果Course不是列表。那么你可以用1.2.0.Final来做得更优雅。

@Mapper
public interface MyMapper {

    @Mapping(target = "targetId", source = "sourceId")
    @Mapping(target = "subjectName", source = "course.courseName")
    @Mapping(target = "members", source = "course.students")
    Target map(Source source);

    @Mapping(target = "memberName", source = "studentName")
    Member toMember(Student student);
}