Hibernate: Proxy konnte nicht initialisiert werden - keine Sitzung (über Referenzkette ...)
Hinweis: Bevor Sie sich über ein Duplikat beschweren, lesen Sie den Inhalt sorgfältig durch, ohne nach dem Titel zu urteilen. Lesen Sie auch Ihre Referenzfrage und die Antwort sorgfältig durch, um festzustellen, ob sie doppelt vorhanden sind. Meiner Erfahrung nach kann das Problem in dieser Frage in verschiedenen Umgebungen auftreten. Zum Beispiel die Antwort für jemanden, der den folgenden Code in @ verwendjsp wird anders sein, für jemanden, der @ verwendSpring wird anders sein und für jemanden, dessen DB klein ist undeager Last ist in Ordnung wird anders sein. Und nein, meine Situation ist keine von ihnen.
Ich schreibe einREST api usingHibernateundJersey. Bitte sehen Sie sich den folgenden Code an.
VerificationCodeJSONService.java - Die JSON-Serviceklasse
@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 - Die Serviceebene
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 - Die Datenbankebene
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 - Die DAO-Ebene
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 - Die DAO-Ebene
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;
}
}
Below sind meineHibernate Mapping-Dateien für die obigen POJOs
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>
Allerdings, wenn ich diesen Code über @ ausführhttp://localhost:8080/example_rest/rest/verificaion_code/getAllVerificationCodes Ich erhalte den folgenden Fehler.
could not initialize proxy - no Session (through reference chain: java.util.ArrayList[0]->beans.VerificaionCode["patient"]->beans.Patient_$_jvst40f_7["diabetesType"])
Wie du sehen kannstdiabetesType ist einObject (Fremdschlüssel) in der Patiententabelle und hat nichts mit @ zu tVerificationCode. Wie kann ich das beheben?
Bitte beachten Sie, dass dies ein @ iREST API. Ich kann diese also nicht wie in einer Web-App in eine JSP laden.
Aktualisiere
Als @ Kayaman empfohlen, habe ich die Updates gemacht, indem ichnull. Bitte überprüfen Sie den folgenden Code. Ich bemerkte, dassverificaionCodes.get(i).getPatient().set...(null) macht den gleichen Fehler wie oben, also habe ich unten versucht, was gut funktioniert.
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;
}