Java Hibernate:无法初始化代理-无会话(通过引用链…)
注意:在任何人抱怨这是重复之前,请确保仔细阅读内容,不要根据标题来判断。还要确保仔细阅读你的参考问题和答案,看它是否重复。根据我现在的经验,这个问题可能在不同的环境下发生。例如,对于在Java Hibernate:无法初始化代理-无会话(通过引用链…),java,hibernate,rest,Java,Hibernate,Rest,注意:在任何人抱怨这是重复之前,请确保仔细阅读内容,不要根据标题来判断。还要确保仔细阅读你的参考问题和答案,看它是否重复。根据我现在的经验,这个问题可能在不同的环境下发生。例如,对于在jsp中使用以下代码的人来说,答案将不同;对于使用Spring的人来说,答案将不同;对于DB较小且渴望加载的人来说,答案将不同。不,我的情况不是他们中的任何一个 我正在使用Hibernate和Jersey编写一个RESTapi。请看下面的代码 VerificationCodeJSONService.java-JS
jsp
中使用以下代码的人来说,答案将不同;对于使用Spring
的人来说,答案将不同;对于DB较小且渴望加载的人来说,答案将不同。不,我的情况不是他们中的任何一个
我正在使用Hibernate
和Jersey
编写一个REST
api。请看下面的代码
VerificationCodeJSONService.java-JSON服务类
@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;
}
}
Patient.java-DAO层
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;
}
}
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;
}
}
下面是我针对上述POJO的Hibernate
映射文件
验证代码.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>
<?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>
如您所见,diabetepe
是患者表中的一个对象
(外键),与验证代码
无关。我怎样才能解决这个问题
请注意,这是一个REST
API。所以我不能像在web应用程序中那样在JSP中加载这些
更新
按照@Kayaman的建议,我通过设置null
来进行更新。请检查下面的代码。我注意到,VerificationCodes.get(I).getPatient().set…(null)
会产生与上面相同的错误,因此我尝试了下面的方法,该方法开始正常工作
VerificationCodeDevice.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;
}
public List getAllVerificationCodes(){
会话会话=verificationCodeDAOInterface.openCurrentSession();
事务=空;
List VerificationCodes=new ArrayList();
试一试{
事务=verificationCodeDAOInterface.openTransaction(会话);
VerificationCodes=verificationCodeDAOInterface.getAllVerificationCodes(会话);
commit();
}捕获(例外情况除外){
例如printStackTrace();
}最后{
session.close();
对于(int i=0;i@Kayaman:也许,你知道在特定情况下如何解决这个问题吗?也许。但是既然你不愿意诚实地回答我,我为什么要帮助你?@Kayaman:我没有请求你来帮助。这是你是否愿意帮助的问题。如果你不想帮助,那也没关系。另外,你问我是否知道潜在的问题或问题问题结束???@Kayaman:哦,嗯,好吧..这很奇怪。代码中绝对没有空的东西(据我所知,也许我错了)。请问您对此有何建议?internet上似乎没有解决此问题的解决方案,不知道是否有人使用Hibernate来做一些与Web ViewNo不同的事情。我的意思是,它与NPE
一样常见,而且只有一个原因。您需要在会话打开时初始化代理。您声称无法执行我渴望获取,这是为什么?而且这与JSP、web或其他类似的东西无关。这是一个纯粹的基本Hibernate东西。为什么不在查询中执行渴望获取?
<?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>
could not initialize proxy - no Session (through reference chain: java.util.ArrayList[0]->beans.VerificaionCode["patient"]->beans.Patient_$$_jvst40f_7["diabetesType"])
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;
}