多嵌套实体上的Spring双向关系

Question

我知道在过去使用spring的双向关系有很多问题，但是我的情况有点不同，因为我使用了3个有两个关系的实体来实现一个医疗系统。

我有三个实体:医生/病人/预约

以下是这三个实体的代码--请注意所有已实现的setter、getter和constructors，但为了清楚起见，请在这里删除

病人类

@Entity
public class resPatient {
@Id
@GeneratedValue( strategy= GenerationType.IDENTITY )
private long code;
private String name;
private String gender;
private String email;
private String mobile;
private int age;

private String notes;


@OneToMany(mappedBy = "patient")
List<resPackageMembership> memberships;

@OneToMany(mappedBy = "patient")
List<resAppointment> appointments;

@OneToMany(fetch = FetchType.LAZY,mappedBy = "patient")
List<resMedImage> medImages;

博士级

 @Entity
 public class resDoctor {

@Id
@GeneratedValue( strategy= GenerationType.IDENTITY )
private long code;
private String name;
private String mobile;



private String email;
private String gender;
private int age;
private  String speciality;

@OneToMany(mappedBy = "doctor")
List<resAppointment> appointments;

约会类

@Entity
public class resAppointment {

@Id
@GeneratedValue( strategy= GenerationType.IDENTITY )
private long code;
private String speciality;
@Basic
@Temporal(TemporalType.TIMESTAMP)
private Date dateCreated;


@Basic
@Temporal(TemporalType.TIMESTAMP)
private Date dateToVisit;
private String status;
private String notes;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "doctorCode")
private resDoctor doctor;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "patientCode")
private resPatient patient;

我的医疗系统的工作方式应该是，当我让一个病人使用我的restful控制器时，我想要所有的病人数据，包括他的预约，但这会导致一个无限循环，因为预约有医生，还有预约等等。

我不能使用@JSONIGNORE，因为有两个关系，我想让病人与他的预约，这应该有医生没有预约数组，不应该有任何病人的数据，因为我已经在病人对象

Answer 1

作为一般的最佳实践，建议将实体与用于rest控制器的数据传输对象分开。在DTO就绪之后，您可以更多地控制在其中包含和序列化哪些数据，以避免循环引用。如果您喜欢签出https://bootify.io，它将从数据库模式生成DTO，但是您仍然需要定义/构建自定义端点。

Answer 2

我最近开发了一个名为豆刀的注释处理器，它支持从任何类生成DTO。您需要通过注释配置。但你不需要改变原来的课程。此库支持在单独的类上进行配置。当然，您可以选择您想要的财产和不需要的财产。还可以通过config类中的静态方法添加新属性。关于你的问题：

// this will generate a DTO class named "resPatientView". 
// You can change this name using genName attribute.
@ViewOf(value=resPatient.class, includePattern = ".*")
public class PatientViewConfigure {
    // here tell the processor to automatically convert the property appointments from List<resAppointment> to List<resAppointmentWithoutPatient>. 
    // resAppointmentWithoutPatient is the generated class configured at the following. 
    // Note, although at this moment it not exists and your idea think it is an error. 
    // this code really can be compiled, and after compiled, all will ok.
    @OverrideViewProperty("appointments")
    private List<resAppointmentWithoutPatient> appointments;
}

// here generated a class named resAppointmentWithoutPatient whick has all properties of resAppointment except patient
@ViewOf(value=resAppointment.class, genName="resAppointmentWithoutPatient", includePattern = ".*", excludes={"patient"})
public class AppointmentWithoutPatientViewConfigure {
    // the doctor property will be converted to its dto version which defined by the configure class DoctorWithoutAppointmentsViewConfigure.
    @OverrideViewProperty("doctor")
    private resDoctorWithoutAppointments doctor;
}

// here we generate a class which has all properties of resDoctor except appointments
@ViewOf(value=resDoctor.class, genName="resDoctorWithoutAppointments", includePattern = ".*", excludes={"appointments"})
public class DoctorWithoutAppointmentsViewConfigure {}

// in you rest controller. return the dto instead of the entities.
resPatient patient = ...
resPatientView dto = resPatientView.read(patient);
List<resPatient> patients = ...
List<resPatientView> dto = resPatientView.read(patients);

最后，类resPatientView将与resPatient具有相同的形状，除非它的约会没有病人属性，而且它的医生属性被替换为没有约会属性的版本。

下面是更多的示例。版本1.10已经准备好了。将修复一些bug，并支持在spring之前管理配置bean。