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java - 使用 org.mapstruct 框架的一对多关系映射

问题描述

如何使用 org.mapstruct 框架映射一对多关系？

DTO 类：

@Data
public class ScheduledJobDTO {

    private String jobName;
    private String jobGroup;
    private String jobClass;
    private String cronExpression;
    private Boolean cronJob;
    private Long repeatTime;
    private Integer repeatCount;
    private Set<ScheduledJobParamsDTO> paramtersDTOs;

}

@Data
@EqualsAndHashCode
public class ScheduledJobParamsDTO {

    String name;
    String value;
}

域类 -

@Data
@Entity
@Table(name = "scheduled_job")
public class ScheduledJob {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Column(name = "job_name")
    private String jobName;
    @Column(name = "job_group")
    private String jobGroup;
    @Column(name = "job_class")
    private String jobClass;
    @Column(name = "cron_expression")
    private String cronExpression;
    @Column(name = "is_cron_job")
    private Boolean cronJob;
    @Column(name = "repeat_time")
    private Long repeatTime;
    @Column(name = "repeat_count")
    private Integer repeatCount;
    @Column(name = "trigger_start_date")
    private LocalDate triggerStartDate;
    @Column(name = "trigger_end_date")
    private LocalDate triggerEndDate;
    @Column(name = "created_at")
    private LocalDate createdAt;
    @Column(name = "modified_at")
    private LocalDate modifiedAt;
    @Column(name = "is_active")
    private Boolean active;
    @OneToMany(mappedBy = "scheduledJob")
    private Set<ScheduledJobParams> parameters;

}

@Data
@Entity
@Table(name = "scheduled_job_params")
@EqualsAndHashCode
public class ScheduledJobParams {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    Long id;
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "scheduled_job_id", nullable = false)
    ScheduledJob scheduledJob;
    String name;
    String value;
}

映射器类 -

@Mapping(source = ".", target = ".")
@Mapping(source = "paramtersDTOs", target = "parameters")
ScheduledJob mapToDomain(ScheduledJobDTO scheduledJobDTO);

现在，上面的映射器正在映射 ScheduledJob 和 ScheduledJobParams，但 ScheduledJobParams 有 ScheduledJob 的引用。

如何将参考 ScheduledJob 映射到 ScheduledJobParams？

标签： javaspringmapstructbidirectional-relation

解决方案

您可以通过@AfterMapping. @MappedTarget这在参考文档中有所描述：12.2。使用映射前和映射后方法进行映射自定义。

// Java 8+ otherwise you need to use an abstract class and a for-loop instead
@Mapper(componentModel = "spring")
public interface ScheduledJobMapper {

    @Mapping(target = "parameters", source = "paramtersDTOs")
    ScheduledJob mapToDomain(ScheduledJobDTO dto);

    @AfterMapping
    default void after(@MappingTarget ScheduledJob domain, ScheduledJobDTO dto) {
        domain.getParameters().forEach(scheduledJobParams -> {
            scheduledJobParams.setScheduledJob(domain);
        });
    }
}

但是，我确信当您从DTO映射回实体时，您不需要填写双向关系（这就是我所理解的“域”）。java.lang.StackOverflowError如果处理不当，请注意打印或序列化此类对象，即 JSON 或 XML 抛出。

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