Hibernate: не удалось инициализировать прокси - нет сеанса (через цепочку ссылок ...)
Примечание. Прежде чем жаловаться на дубликат, обязательно просмотрите содержимое, не судя по названию. Также внимательно прочитайте ваш справочный вопрос и ответ, чтобы увидеть, является ли он дубликатом. По моему опыту, проблема в этом вопросе может возникнуть в разных средах. Например, ответ для кого-то, используя приведенный ниже код вjsp будет другим, для кого-то, использующегоSpring будет отличаться и для кого-то, чья БД мала иeager нагрузка в порядке будет отличаться. И нет, моя ситуация не какая-либо из них.
Я пишуREST API с использованиемHibernateа такжеJersey, Пожалуйста, посмотрите на приведенный ниже код.
VerificationCodeJSONService.java - Сервисный класс JSON
@Path("/verificaion_code")
public class VerificationCodeJSONService {
@GET
@Path("/getAllVerificationCodes")
@Produces(MediaType.APPLICATION_JSON)
public List<VerificaionCode> getAllVerificationCodes() {
VerificationCodeService verificationCodeService=new VerificationCodeService();
List<VerificaionCode> list = verificationCodeService.getAllVerificationCodes();
return list;
}
}
VerificationCodeService.java - Сервисный уровень
public class VerificationCodeService {
private static VerificationCodeDAOInterface verificationCodeDAOInterface;
public VerificationCodeService() {
verificationCodeDAOInterface = new VerificationCodeDAOImpl();
}
public List<VerificaionCode> getAllVerificationCodes() {
Session session = verificationCodeDAOInterface.openCurrentSession();
Transaction transaction = null;
List<VerificaionCode> verificaionCodes = new ArrayList<VerificaionCode>();
try {
transaction = verificationCodeDAOInterface.openTransaction(session);
verificaionCodes = verificationCodeDAOInterface.getAllVerificationCodes(session);
transaction.commit();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
session.close();
}
return verificaionCodes;
}
}
VerificationCodeDAOImpl.java - Уровень базы данных
public class VerificationCodeDAOImpl implements VerificationCodeDAOInterface{
private static final SessionFactoryBuilder sessionFactoryBuilder = SessionFactoryBuilder.getInstance();
@Override
public List<VerificaionCode> getAllVerificationCodes(Session session) {
List<VerificaionCode> verificaionCodes=(List<VerificaionCode>)session.createQuery("from VerificaionCode").list();
return verificaionCodes;
}
}
VerificationCode.java - слой DAO
public class VerificaionCode implements java.io.Serializable {
private Integer idverificaionCode;
private Patient patient;
private String code;
private Date dateCreated;
private Date lastUpdated;
public VerificaionCode() {
}
public VerificaionCode(Patient patient, String code, Date lastUpdated) {
this.patient = patient;
this.code = code;
this.lastUpdated = lastUpdated;
}
public VerificaionCode(Patient patient, String code, Date dateCreated, Date lastUpdated) {
this.patient = patient;
this.code = code;
this.dateCreated = dateCreated;
this.lastUpdated = lastUpdated;
}
public Integer getIdverificaionCode() {
return this.idverificaionCode;
}
public void setIdverificaionCode(Integer idverificaionCode) {
this.idverificaionCode = idverificaionCode;
}
public Patient getPatient() {
return this.patient;
}
public void setPatient(Patient patient) {
this.patient = patient;
}
public String getCode() {
return this.code;
}
public void setCode(String code) {
this.code = code;
}
public Date getDateCreated() {
return this.dateCreated;
}
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
public Date getLastUpdated() {
return this.lastUpdated;
}
public void setLastUpdated(Date lastUpdated) {
this.lastUpdated = lastUpdated;
}
}
Patient.java - слой DAO
public class Patient implements java.io.Serializable {
private Integer idpatient;
private DiabetesType diabetesType;
private Language language;
private String customId;
private String diabetesOther;
private String firstName;
private String lastName;
private String email;
private Date dob;
private String parentEmail;
private String gender;
private Date diagnosedDate;
private Double height;
private Double weight;
private String heightUnit;
private String weightUnit;
private String theme;
private String userName;
private String password;
private Date dateCreated;
private Date lastUpdated;
public Patient() {
}
public Patient(DiabetesType diabetesType, Language language, String customId, String firstName, String email, Date dob, String gender, String theme, String userName, String password, Date lastUpdated) {
this.diabetesType = diabetesType;
this.language = language;
this.customId = customId;
this.firstName = firstName;
this.email = email;
this.dob = dob;
this.gender = gender;
this.theme = theme;
this.userName = userName;
this.password = password;
this.lastUpdated = lastUpdated;
}
public Integer getIdpatient() {
return this.idpatient;
}
public void setIdpatient(Integer idpatient) {
this.idpatient = idpatient;
}
public DiabetesType getDiabetesType() {
return this.diabetesType;
}
public void setDiabetesType(DiabetesType diabetesType) {
this.diabetesType = diabetesType;
}
public Language getLanguage() {
return this.language;
}
public void setLanguage(Language language) {
this.language = language;
}
public String getCustomId() {
return this.customId;
}
public void setCustomId(String customId) {
this.customId = customId;
}
public String getDiabetesOther() {
return this.diabetesOther;
}
public void setDiabetesOther(String diabetesOther) {
this.diabetesOther = diabetesOther;
}
public String getFirstName() {
return this.firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return this.lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return this.email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getDob() {
return this.dob;
}
public void setDob(Date dob) {
this.dob = dob;
}
public String getParentEmail() {
return this.parentEmail;
}
public void setParentEmail(String parentEmail) {
this.parentEmail = parentEmail;
}
public String getGender() {
return this.gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getDiagnosedDate() {
return this.diagnosedDate;
}
public void setDiagnosedDate(Date diagnosedDate) {
this.diagnosedDate = diagnosedDate;
}
public Double getHeight() {
return this.height;
}
public void setHeight(Double height) {
this.height = height;
}
public Double getWeight() {
return this.weight;
}
public void setWeight(Double weight) {
this.weight = weight;
}
public String getHeightUnit() {
return this.heightUnit;
}
public void setHeightUnit(String heightUnit) {
this.heightUnit = heightUnit;
}
public String getWeightUnit() {
return this.weightUnit;
}
public void setWeightUnit(String weightUnit) {
this.weightUnit = weightUnit;
}
public String getTheme() {
return this.theme;
}
public void setTheme(String theme) {
this.theme = theme;
}
public String getUserName() {
return this.userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
public Date getDateCreated() {
return this.dateCreated;
}
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
public Date getLastUpdated() {
return this.lastUpdated;
}
public void setLastUpdated(Date lastUpdated) {
this.lastUpdated = lastUpdated;
}
}
Ниже моиHibernate файлы сопоставления для вышеуказанных POJO
VerificaionCode.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- Generated Sep 23, 2016 3:21:00 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
<class name="beans.VerificaionCode" table="verificaion_code" catalog="myglukose" optimistic-lock="version">
<id name="idverificaionCode" type="java.lang.Integer">
<column name="idverificaion_code" />
<generator class="identity" />
</id>
<many-to-one name="patient" class="beans.Patient" fetch="select">
<column name="patient_idpatient" not-null="true" />
</many-to-one>
<property name="code" type="string">
<column name="code" length="45" not-null="true" />
</property>
<property name="dateCreated" type="timestamp">
<column name="date_created" length="19" />
</property>
<property name="lastUpdated" type="timestamp">
<column name="last_updated" length="19" not-null="true" />
</property>
</class>
</hibernate-mapping>
Patient.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- Generated Sep 23, 2016 3:21:00 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
<class name="beans.Patient" table="patient" catalog="myglukose" optimistic-lock="version">
<id name="idpatient" type="java.lang.Integer">
<column name="idpatient" />
<generator class="identity" />
</id>
<many-to-one name="diabetesType" class="beans.DiabetesType" fetch="select">
<column name="diabetes_type_iddiabetes_type" not-null="true" />
</many-to-one>
<many-to-one name="language" class="beans.Language" fetch="select">
<column name="language_idlanguage" not-null="true" />
</many-to-one>
<property name="customId" type="string">
<column name="custom_id" length="45" not-null="true" />
</property>
<property name="diabetesOther" type="string">
<column name="diabetes_other" length="45" />
</property>
<property name="firstName" type="string">
<column name="first_name" length="100" not-null="true" />
</property>
<property name="lastName" type="string">
<column name="last_name" length="100" />
</property>
<property name="email" type="string">
<column name="email" length="45" not-null="true" />
</property>
<property name="dob" type="date">
<column name="dob" length="10" not-null="true" />
</property>
<property name="parentEmail" type="string">
<column name="parent_email" length="45" />
</property>
<property name="gender" type="string">
<column name="gender" length="45" not-null="true" />
</property>
<property name="diagnosedDate" type="date">
<column name="diagnosed_date" length="10" />
</property>
<property name="height" type="java.lang.Double">
<column name="height" precision="22" scale="0" />
</property>
<property name="weight" type="java.lang.Double">
<column name="weight" precision="22" scale="0" />
</property>
<property name="heightUnit" type="string">
<column name="height_unit" length="45" />
</property>
<property name="weightUnit" type="string">
<column name="weight_unit" length="45" />
</property>
<property name="theme" type="string">
<column name="theme" length="45" not-null="true" />
</property>
<property name="userName" type="string">
<column name="user_name" length="45" not-null="true" />
</property>
<property name="password" type="string">
<column name="password" length="45" not-null="true" />
</property>
<property name="dateCreated" type="timestamp">
<column name="date_created" length="19" />
</property>
<property name="lastUpdated" type="timestamp">
<column name="last_updated" length="19" not-null="true">
<comment>Stores the basic information of the patient</comment>
</column>
</property>
</class>
</hibernate-mapping>
Однако, когда я запускаю этот код черезhttp://localhost:8080/example_rest/rest/verificaion_code/getAllVerificationCodes Я получаю ошибку ниже.
could not initialize proxy - no Session (through reference chain: java.util.ArrayList[0]->beans.VerificaionCode["patient"]->beans.Patient_$_jvst40f_7["diabetesType"])
Как вы видетеdiabetesType являетсяObject (Внешний ключ) в таблице пациента и не имеет ничего общего сVerificationCode, Как я могу это исправить?
Обратите внимание, что этоREST API. Поэтому я не могу загрузить их в JSP, как в веб-приложении.
Обновить
Как рекомендовал @Kayaman, я сделал обновления, сделавnull, Пожалуйста, проверьте код ниже. Я заметил, чтоverificaionCodes.get(i).getPatient().set...(null) делает ту же ошибку, что и выше, поэтому я попробовал ниже, который начал работать нормально.
VerificationCodeService.java
public List<VerificaionCode> getAllVerificationCodes() {
Session session = verificationCodeDAOInterface.openCurrentSession();
Transaction transaction = null;
List<VerificaionCode> verificaionCodes = new ArrayList<VerificaionCode>();
try {
transaction = verificationCodeDAOInterface.openTransaction(session);
verificaionCodes = verificationCodeDAOInterface.getAllVerificationCodes(session);
transaction.commit();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
session.close();
for(int i=0;i<verificaionCodes.size();i++)
{
Patient p = new Patient();
System.out.println(verificaionCodes.get(i).getPatient().getIdpatient());
Integer idpatient = verificaionCodes.get(i).getPatient().getIdpatient();
p.setIdpatient(idpatient);
verificaionCodes.get(i).setPatient(p);
}
}
return verificaionCodes;
}