Во-первых, позвольте мне объяснить мой вариант использования. Это довольно прямолинейно. Существует сущность «Пользователь» и сущность «Служба». У меня есть связь ManytoMany между пользователем и службой, использующая UserService в качестве присоединяемой сущности (присоединенной таблицы). Первоначально будет некоторый набор пользователей и некоторый набор служб. Пользователи могут подписаться на любую услугу в любой момент времени. В этом случае запись будет добавлена в UserService. Но я получаю исключение нулевого указателя, когда пытаюсь создать новую ассоциацию UserService. Я мог бы создать пользователя и сервис по отдельности.
Мои сущности: User.java
package dao.models;
import java.io.Serializable;
import javax.persistence.*;
import com.fasterxml.jackson.annotation.JsonBackReference;
@Entity
@org.hibernate.annotations.Proxy(lazy=false)
@Table(name="`user`", schema="emm")
public class User implements Serializable {
public User() {
}
@Column(name="id", nullable=false, unique=true)
@Id
@GeneratedValue(generator="EMM_USER_ID_GENERATOR")
@org.hibernate.annotations.GenericGenerator(name="EMM_USER_ID_GENERATOR", strategy="native")
private long id;
@ManyToOne(targetEntity=dao.models.Tenant.class, fetch=FetchType.LAZY)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.LOCK})
@JoinColumns({ @JoinColumn(name="tenant_id", referencedColumnName="id", nullable=false) })
@org.hibernate.annotations.LazyToOne(value=org.hibernate.annotations.LazyToOneOption.NO_PROXY)
private dao.models.Tenant tenant;
@OneToOne(targetEntity=dao.models.Person.class, fetch=FetchType.LAZY)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.LOCK})
@JoinColumns({ @JoinColumn(name="Person_id", nullable=false) })
@org.hibernate.annotations.LazyToOne(value=org.hibernate.annotations.LazyToOneOption.NO_PROXY)
private dao.models.Person person;
@Column(name="password", nullable=true, length=255)
private String password;
@Column(name="email", nullable=false, length=255)
private String email;
@Column(name="status", nullable=true, length=255)
private String status;
@ManyToMany(mappedBy="user", targetEntity=dao.models.TenantGroup.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.LOCK})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.TenantGroup> group = new java.util.ArrayList<dao.models.TenantGroup>();
@OneToMany(mappedBy="user", targetEntity=dao.models.UserService.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.LOCK})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.UserService> userService = new java.util.ArrayList<dao.models.UserService>();
public void setId(long value) {
this.id = value;
}
public long getId() {
return id;
}
public void setPassword(String value) {
this.password = value;
}
public String getPassword() {
return password;
}
public void setEmail(String value) {
this.email = value;
}
public String getEmail() {
return email;
}
public void setStatus(String value) {
this.status = value;
}
public String getStatus() {
return status;
}
public void setTenant(dao.models.Tenant value) {
this.tenant = value;
}
public dao.models.Tenant getTenant() {
return tenant;
}
public void setPerson(dao.models.Person value) {
this.person = value;
}
public dao.models.Person getPerson() {
return person;
}
public void setGroup(java.util.List<dao.models.TenantGroup> value) {
this.group = value;
}
public java.util.List<dao.models.TenantGroup> getGroup() {
return group;
}
public java.util.List<dao.models.UserService> getUserService() {
return userService;
}
public void setUserService(
java.util.List<dao.models.UserService> userService) {
this.userService = userService;
}
public String toString() {
return String.valueOf(getId());
}
}
Сервисная организация
package dao.models;
import java.io.Serializable;
import javax.persistence.*;
import com.fasterxml.jackson.annotation.JsonBackReference;
@Entity
@org.hibernate.annotations.Proxy(lazy=false)
@Table(name="service", schema="emm")
public class Service implements Serializable {
public Service() {
}
@Column(name="service_id", nullable=false, unique=true)
@Id
@GeneratedValue(generator="EMM_SERVICE_SERVICE_ID_GENERATOR")
@org.hibernate.annotations.GenericGenerator(name="EMM_SERVICE_SERVICE_ID_GENERATOR", strategy="native")
private long id;
@Column(name="service_name", nullable=false, length=255)
@org.hibernate.annotations.Index(name="service_service_name")
private String serviceName;
@Column(name="description", nullable=true, length=255)
private String description;
@Column(name="app_key", nullable=false, length=255)
private String appKey;
@Column(name="app_token", nullable=false, length=255)
private String appToken;
@Column(name="learnmoreurl", length=255)
private String learnMoreURL;
@Column(name="trialurl", length=255)
private String trialURL;
@ManyToMany(mappedBy="service", targetEntity=dao.models.Device.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.LOCK})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.Device> device = new java.util.ArrayList<dao.models.Device>();
@OneToMany(mappedBy="service", targetEntity=dao.models.ServiceParam.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.DELETE})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.ServiceParam> serviceParams = new java.util.ArrayList<dao.models.ServiceParam>();
@OneToMany(mappedBy="service", targetEntity=dao.models.TenantService.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.PERSIST, org.hibernate.annotations.CascadeType.MERGE,
org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.DELETE_ORPHAN})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.TenantService> tenantService = new java.util.ArrayList<dao.models.TenantService>();
@OneToMany(mappedBy="service", targetEntity=dao.models.UserService.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.DELETE})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.UserService> userService = new java.util.ArrayList<dao.models.UserService>();
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getServiceName() {
return serviceName;
}
public void setServiceName(String serviceName) {
this.serviceName = serviceName;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getAppKey() {
return appKey;
}
public void setAppKey(String appKey) {
this.appKey = appKey;
}
public String getAppToken() {
return appToken;
}
public void setAppToken(String appToken) {
this.appToken = appToken;
}
public String getLearnMoreURL() {
return learnMoreURL;
}
public void setLearnMoreURL(String learnMoreURL) {
this.learnMoreURL = learnMoreURL;
}
public String getTrialURL() {
return trialURL;
}
public void setTrialURL(String trialURL) {
this.trialURL = trialURL;
}
public java.util.List<dao.models.Device> getDevice() {
return device;
}
public void setDevice(java.util.List<dao.models.Device> device) {
this.device = device;
}
public java.util.List<dao.models.ServiceParam> getServiceParams() {
return serviceParams;
}
public void setServiceParams(
java.util.List<dao.models.ServiceParam> serviceParams) {
this.serviceParams = serviceParams;
}
public java.util.List<dao.models.TenantService> getTenantService() {
return tenantService;
}
public void setTenantService(
java.util.List<dao.models.TenantService> tenantService) {
this.tenantService = tenantService;
}
public java.util.List<dao.models.UserService> getUserService() {
return userService;
}
public void setUserService(
java.util.List<dao.models.UserService> userService) {
this.userService = userService;
}
public String toString() {
return String.valueOf(getId());
}
}
И, наконец, объект соединения
UserService.java
package dao.models;
import java.io.Serializable;
import javax.persistence.*;
@Entity
@org.hibernate.annotations.Proxy(lazy=false)
@Table(name="user_service" ,schema="emm")
public class UserService implements Serializable {
public UserService() {
}
@Column(name="id", nullable=false, unique=true)
@Id
@GeneratedValue(generator="EMM_USER_SERVICE_ID_GENERATOR")
@org.hibernate.annotations.GenericGenerator(name="EMM_USER_SERVICE_ID_GENERATOR", strategy="native")
private long id;
@ManyToOne(targetEntity=dao.models.User.class, fetch=FetchType.LAZY)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.LOCK})
@JoinColumns({ @JoinColumn(name="user_id", referencedColumnName="id", nullable=false) })
@org.hibernate.annotations.LazyToOne(value=org.hibernate.annotations.LazyToOneOption.NO_PROXY)
private dao.models.User user;
@ManyToOne(targetEntity=dao.models.Service.class, fetch=FetchType.LAZY)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.LOCK})
@JoinColumns({ @JoinColumn(name="service_id", referencedColumnName="service_id", nullable=false) })
@org.hibernate.annotations.LazyToOne(value=org.hibernate.annotations.LazyToOneOption.NO_PROXY)
private dao.models.Service service;
@Column(name="param_name", nullable=false)
private String paramName;
@Column(name="param_value", nullable=true)
private String paramValue;
@OneToMany(mappedBy="userService", targetEntity=dao.models.UserServiceToken.class)
@org.hibernate.annotations.Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE, org.hibernate.annotations.CascadeType.LOCK})
@org.hibernate.annotations.LazyCollection(org.hibernate.annotations.LazyCollectionOption.TRUE)
private java.util.List<dao.models.UserServiceToken> userServiceToken = new java.util.ArrayList<dao.models.UserServiceToken>();
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public dao.models.User getUser() {
return user;
}
public void setUser(dao.models.User user) {
this.user = user;
}
public dao.models.Service getService() {
return service;
}
public void setService(dao.models.Service service) {
this.service = service;
}
public String getParamName() {
return paramName;
}
public void setParamName(String paramName) {
this.paramName = paramName;
}
public String getParamValue() {
return paramValue;
}
public void setParamValue(String paramValue) {
this.paramValue = paramValue;
}
public java.util.List<dao.models.UserServiceToken> getUserServiceToken() {
return userServiceToken;
}
public void setUserServiceToken(
java.util.List<dao.models.UserServiceToken> userServiceToken) {
this.userServiceToken = userServiceToken;
}
public String toString() {
return String.valueOf(getId());
}
}
Теперь моя проблема, запросы GET работают правильно, но я получаю исключение нулевого указателя, когда пытаюсь создать новый UserService.
POST: http://localhost:8080/em/api/userServices/
Я пытаюсь связать пользователя 1 со службой 2. Запрос:
{
"paramName": "p1",
"paramValue": "v1",
"service": {
"href": `"http://localhost:8080/em/api/userServices/1/service/2"`
},
"user": {
"href": `"http://localhost:8080/em/api/userServices/1/user/1"`
}
}
Сообщение об ошибке:
{
"cause": {
"cause": {
"cause": null,
"message": null
},
"message": "(was java.lang.NullPointerException) (through reference chain: dao.models.UserService[\"service\"])"
},
"message": "Could not read JSON: (was java.lang.NullPointerException) (through reference chain: dao.models.UserService[\"service\"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: dao.models.UserService[\"service\"])"
}
GET http://localhost:8080/em/api/userServices
дает мне следующий вывод:
{
"_links" : {
"self" : {
"href" : "http://localhost:8080/em/api/userServices{?page,size,sort}",
"templated" : true
}
},
"_embedded" : {
"userServices" : [ {
"paramName" : "p1",
"paramValue" : "v1",
"_links" : {
"self" : {
"href" : "http://localhost:8080/em/api/userServices/1"
},
"userServiceToken" : {
"href" : "http://localhost:8080/em/api/userServices/1/userServiceToken"
},
"user" : {
"href" : "http://localhost:8080/em/api/userServices/1/user"
},
"service" : {
"href" : "http://localhost:8080/em/api/userServices/1/service"
}
}
}, {
"paramName" : "pone",
"paramValue" : "vone",
"_links" : {
"self" : {
"href" : "http://localhost:8080/em/api/userServices/2"
},
"userServiceToken" : {
"href" : "http://localhost:8080/em/api/userServices/2/userServiceToken"
},
"user" : {
"href" : "http://localhost:8080/em/api/userServices/2/user"
},
"service" : {
"href" : "http://localhost:8080/em/api/userServices/2/service"
}
}
} ]
},
"page" : {
"size" : 20,
"totalElements" : 2,
"totalPages" : 1,
"number" : 0
}
}
Кто-нибудь успешно внедрил ассоциацию ManyToMany с использованием Spring-data-rest. Если это так, пожалуйста, помогите мне в этом отношении