I use hibernate to create a rest api. I create a method to get all items in a table.
public List<Language> getAllLanguages(Session session) {
List<Language> languages=(List<Language>)session.createQuery("from Language").list();
return languages;
}
This is my Language.java
public class Language implements java.io.Serializable {
private Integer idlanguage;
private String language;
private Set<Patient> patients = new HashSet<Patient>(0);
public Language() {
}
public Language(String language) {
this.language = language;
}
public Language(String language, Set<Patient> patients) {
this.language = language;
this.patients = patients;
}
public Integer getIdlanguage() {
return this.idlanguage;
}
public void setIdlanguage(Integer idlanguage) {
this.idlanguage = idlanguage;
}
public String getLanguage() {
return this.language;
}
public void setLanguage(String language) {
this.language = language;
}
public Set<Patient> getPatients() {
return this.patients;
}
public void setPatients(Set<Patient> patients) {
this.patients = patients;
}
}
And this is my Patient.java
// Generated Sep 14, 2016 4:33:23 PM by Hibernate Tools 4.3.1
import beans.DiabetesType;
import beans.Illness;
import beans.Language;
import beans.Reminder;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;
/**
* Patient generated by hbm2java
*/
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 userName;
private String password;
private Date dateCreated;
private Date lastUpdated;
private Set<Illness> illnesses = new HashSet<Illness>(0);
private Set<Reminder> reminders = new HashSet<Reminder>(0);
public Patient() {
}
public Patient(Integer idpatient, String password) {
this.idpatient = idpatient;
this.password = password;
}
public Patient(DiabetesType diabetesType, Language language, String customId, String firstName, String userName, String password, Date lastUpdated) {
this.diabetesType = diabetesType;
this.language = language;
this.customId = customId;
this.firstName = firstName;
this.userName = userName;
this.password = password;
this.lastUpdated = lastUpdated;
}
public Patient(DiabetesType diabetesType, Language language, String customId, String diabetesOther, String firstName, String lastName, String userName, String password, Date dateCreated, Date lastUpdated, Set<Illness> illnesses, Set<Reminder> reminders) {
this.diabetesType = diabetesType;
this.language = language;
this.customId = customId;
this.diabetesOther = diabetesOther;
this.firstName = firstName;
this.lastName = lastName;
this.userName = userName;
this.password = password;
this.dateCreated = dateCreated;
this.lastUpdated = lastUpdated;
this.illnesses = illnesses;
this.reminders = reminders;
}
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 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;
}
public Set<Illness> getIllnesses() {
return this.illnesses;
}
public void setIllnesses(Set<Illness> illnesses) {
this.illnesses = illnesses;
}
public Set<Reminder> getReminders() {
return this.reminders;
}
public void setReminders(Set<Reminder> reminders) {
this.reminders = reminders;
}
}
Important: The beans and mappings are reverse engineered from MySQL database, via NetBeans. I do not need to get any data related to patient when calling getAllLangauges. My language table has only 2 columns, idlanguage and language. Patient table has a foriegn key of language table
Before using this method in rest api , it worked perfectly without any exception. But when I used this in rest api, it created a complexity in there.
I am not using annotations in here. I used hibernate reverse engineering wizard to map above entities . This is my rest api method.
#Path("/language")
public class LanguageJSONService {
#GET
#Path("/getAllLanguages")
#Produces(MediaType.APPLICATION_JSON)
public List<Language> getAllLanguages(){
LanguageService languageService=new LanguageService();
List<Language> list = languageService.getAllLanguages();
return list;
}
}
This is the way how I call the method,
Client client = ClientBuilder.newClient();
List<Language> list = client.target("http://localhost:8080/simple_rest/rest")
.path("/language/getAllLanguages")
.request(MediaType.APPLICATION_JSON)
.get(new GenericType<List<Language>>() {
});
for (int i = 0; i < list.size(); i++) {
System.out.println("Id - " + list.get(i).getIdlanguage() + " Language - " + list.get(i).getLanguage());
}
When I call the method ,
failed to lazily initialize a collection of role: beans.Language.patients, could not initialize proxy - no Session (through reference chain: java.util.ArrayList[0]->beans.Language["patients"])
is occurred.
Interestingly, if I did not close the session, then I get an output like below which is totally something else, seems like it is trying to display its foreign key tables and their foreign key tables and so on...
[{"idlanguage":1,"language":"English","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":{"iddiabetesType":1,"type":"Sever","patients":
[{"idpatient":1,"diabetesType":
Have any ideas about this problem ?
Update
my configuration file
hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="show_sql">true</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/*****</property>
<property name="hibernate.connection.username">*****</property>
<property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.max_size">20</property>
<property name="hibernate.c3p0.timeout">3000</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.idle_test_period">300</property>
<property name="hibernate.c3p0.testConnectionOnCheckout">true</property>
<property name="hibernate.c3p0.preferredTestQuery">SELECT 1</property>
<property name="hibernate.connection.password">************</property>
<mapping resource="beans/Reminder.hbm.xml"/>
<mapping resource="beans/Food.hbm.xml"/>
<mapping resource="beans/Patient.hbm.xml"/>
<mapping resource="beans/Illness.hbm.xml"/>
<mapping resource="beans/Language.hbm.xml"/>
</session-factory>
</hibernate-configuration>
Language.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 14, 2016 4:33:23 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
<class name="beans.Language" table="language" catalog="myglukose" optimistic-lock="version">
<id name="idlanguage" type="java.lang.Integer">
<column name="idlanguage" />
<generator class="identity" />
</id>
<property name="language" type="string">
<column name="language" length="45" not-null="true" />
</property>
<set name="patients" table="patient" inverse="true" lazy="true" fetch="select">
<key>
<column name="language_idlanguage" not-null="true" />
</key>
<one-to-many class="beans.Patient" />
</set>
</class>
</hibernate-mapping>
This is my patient mapping file,
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 14, 2016 4:33:23 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="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>
<set name="illnesses" table="illness" inverse="true" lazy="true" fetch="select">
<key>
<column name="patient_idpatient" not-null="true" />
</key>
<one-to-many class="beans.Illness" />
</set>
<set name="reminders" table="reminder" inverse="true" lazy="true" fetch="select">
<key>
<column name="patient_idpatient" not-null="true" />
</key>
<one-to-many class="beans.Reminder" />
</set>
</class>
</hibernate-mapping>
Your json converter tries to serialize the whole entity, which contains the list of all patients speaking each language. From what i understood, the list of patient in the json is not expected. So you have three options (ordered in which i would consider them) :
Remove the mapping to patients in Language entity. Do you need to get acces
s to patients from the language entity ? If not remove this mapping.
Create a Language DTO where you transfer your data before exiting the tx layer. This way whoever calls the service will never get a LazyInitException. No surprise : DTO fields are always set eagerly.
Configure your json converter to not serialize the patient fields. You've not said which json lib you're using. Some of them give you an annotation to ignore some fields (#JsonIgnore for Jackson for example), other requires java configuration.
To apply the first solution, update those files this way :
Language.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 14, 2016 4:33:23 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
<class name="beans.Language" table="language" catalog="myglukose" optimistic-lock="version">
<id name="idlanguage" type="java.lang.Integer">
<column name="idlanguage" />
<generator class="identity" />
</id>
<property name="language" type="string">
<column name="language" length="45" not-null="true" />
</property>
</class>
</hibernate-mapping>
Language.java
public class Language implements java.io.Serializable {
private Integer idlanguage;
private String language;
protected Language() {
}
public Language(String language) {
this.language = language;
}
public Integer getIdlanguage() {
return this.idlanguage;
}
protected void setIdlanguage(Integer idlanguage) {
this.idlanguage = idlanguage;
}
public String getLanguage() {
return this.language;
}
public void setLanguage(String language) {
this.language = language;
}
}
I've updated the no-arg constructor and setId method to protected. You can even update them to private : only hibernate should ever use them (and it can use private fields / methods).
When you try to access a lazy field you need to do that before the session of hibernate is closed.
When you exit from the context of the session is not possible for hibernate to access the database if needed, so a LazyInitializationException is thrown.
From javadoc:
Indicates access to unfetched data outside of a session context. For example, when an uninitialized proxy or collection is accessed after the session was closed.
From current explanation I am not able to see you are doing like : language.getPatients();
But if you are writing HQL query to access all patients form Language Entity then I think you should use join . As i can see the exception if related to LazyInitializationException in beans.Language.patients.
so i will suggest below code ...Check if it usefull to you or not..
public List<Language> getAllLanguages(Session session) {
List<Language> languages=(List<Language>)session.createQuery("from Language as l JOIN l.patients").list();
return languages;
}
I am getting " org.hibernate.PropertyAccessException" due to null values in my database table. How to handle the exception?
My files are
FetchTest.java
package com.raj.java.hiberanteDemos;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class FetchTest {
public static void main(String[] args) {
Configuration cfg=new Configuration().configure("hibernate.cfg.xml");
SessionFactory factory=cfg.buildSessionFactory();
Session session1=factory.openSession();
Employee emp1=(Employee)session1.get(Employee.class,7839);
System.out.println(emp1.getEmpno()+" "+emp1.getEname()+" "+emp1.getSal());
session1.close();
Session session2=factory.openSession();
Employee emp2=(Employee)session2.load(Employee.class,7839);
System.out.println(emp2.getEmpno()+" "+emp2.getEname()+" "+emp2.getSal());
session2.close();
}
}
Employee.java
package com.raj.java.hiberanteDemos;
import java.sql.Date;
class Employee {
private int empno, mgr, deptnumber;
private String ename, job;
private double sal, comm;
private Date hiredate;
public int getEmpno() {
return empno;
}
public void setEmpno(int empno) {
this.empno = empno;
}
public int getMgr() {
return mgr;
}
public void setMgr(int mgr) {
this.mgr = mgr;
}
public int getDeptnumber() {
return deptnumber;
}
public void setDeptnumber(int deptnumber) {
this.deptnumber = deptnumber;
}
public String getJob() {
return job;
}
public void setJob(String job) {
this.job = job;
}
public double getComm() {
return comm;
}
public void setComm(double comm) {
this.comm = comm;
}
public Date getHiredate() {
return hiredate;
}
public void setHiredate(Date hiredate) {
this.hiredate = hiredate;
}
public String getEname() {
return ename;
}
public void setEname(String ename) {
this.ename = ename;
}
public double getSal() {
return sal;
}
public void setSal(double sal) {
this.sal = sal;
}
}
hibernate.cfg.xml
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hbm2ddl.auto">update</property>
<property name="dialect">org.hibernate.dialect.Oracle9Dialect
</property>
<property name="connection.url">someValidurl</property>
<property name="connection.username">username</property>
<property name="connection.password">password</property>
<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="hibernate.show_sql">true</property>
<property name="cache.provider_class">org.hibernate.cache.EhCacheProvider</property>
<property name="hibernate.cache.use_second_level_cache">true</property>
<mapping resource="employee.hbm.xml"></mapping>
</session-factory>
</hibernate-configuration>
employee.hbm.xml
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<!-- <class name="com.javatpoint.mypackage.Employee" table="employee"> <id
name="empid"> <generator class="assigned"></generator> </id> <property name="firstName"></property>
<property name="lastName"></property> </class> -->
<class name="com.raj.java.hiberanteDemos.Employee" table="emp">
<id name="empno" type="int" column="EMPNO">
<generator class="increment" />
</id>
<property name="ename" type="java.lang.String" />
<property name="mgr" type="int" />
<property name="deptnumber" type="int" column="deptno" />
<property name="job" type="java.lang.String" />
<property name="sal" type="double" />
<property name="comm" type="double" />
<property name="hiredate" type="java.sql.Date" />
</class>
</hibernate-mapping>
When I ran this application I am getting below error message.
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Hibernate: select employee0_.EMPNO as EMPNO0_0_, employee0_.ename as ename0_0_, employee0_.mgr as mgr0_0_, employee0_.deptno as deptno0_0_, employee0_.job as job0_0_, employee0_.sal as sal0_0_, employee0_.comm as comm0_0_, employee0_.hiredate as hiredate0_0_ from emp employee0_ where employee0_.EMPNO=?
Exception in thread "main" org.hibernate.PropertyAccessException: exception setting property value with CGLIB (set hibernate.cglib.use_reflection_optimizer=false for more info) setter of com.raj.java.hiberanteDemos.Employee.setMgr
at org.hibernate.tuple.PojoEntityTuplizer.setPropertyValuesWithOptimizer(PojoEntityTuplizer.java:215)
at org.hibernate.tuple.PojoEntityTuplizer.setPropertyValues(PojoEntityTuplizer.java:185)
at org.hibernate.persister.entity.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:3232)
at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:129)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:842)
at org.hibernate.loader.Loader.doQuery(Loader.java:717)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.loadEntity(Loader.java:1785)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:47)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:41)
at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:2730)
at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:365)
at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:346)
at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:123)
at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:177)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:87)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:862)
at org.hibernate.impl.SessionImpl.get(SessionImpl.java:799)
at org.hibernate.impl.SessionImpl.get(SessionImpl.java:792)
at com.raj.java.hiberanteDemos.FetchTest.main(FetchTest.java:13)
Caused by: net.sf.cglib.beans.BulkBeanException
at com.raj.java.hiberanteDemos.Employee$$BulkBeanByCGLIB$$142cfd75.setPropertyValues(<generated>)
at org.hibernate.tuple.PojoEntityTuplizer.setPropertyValuesWithOptimizer(PojoEntityTuplizer.java:212)
... 19 more
Caused by: java.lang.NullPointerException
... 21 more
my emp table data
when I update all the null values with 0 or some other values its working fine.
Please help me in solving the error without updating null values in database table.
Thanks in Advance,
Raj
I would personally recommend to actually "clean" the database values, maybe setting the column not nullable.
But if this can't be done, what you can do is modify your setters, so that it checks for null:
public void setComm(Double comm) {
if(null != comm){
this.comm = comm;
}else{
this.comm = 0;
}
}
hope this helps
Your mgr-Property is int, which does not allow null. Change it to Integer, which allows null. Or make a default value for your mgr column.
The best way to avoid Hibernate's attempts at setting null values to primitives is to use Wrapper classes (Integer, Long, Double...); and especially, if you need to tack on a column or 2 to an existing table. Auto-boxing is your friend.
I connected data base with hibernate to my application with this settings:
hibernateContext.xml
<bean id="hibernateTemplate" class="org.springframework.orm.hibernate4.HibernateTemplate">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="hibernateUserDao" class="org.springframework.web.basepackage.HibernateUserDao">
<property name="hibernateTemplate" ref="hibernateTemplate" />
</bean>
this is hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/fullproject</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">admin</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<property name="hibernate.show_sql">true</property>
<mapping resource="user.hbm.xml" />
</session-factory>
</hibernate-configuration>
this is user.hbm.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="org.springframework.web.basepackage.User" table="users">
<id name="id" column="id">
<generator class="native" />
</id>
<property name="login" column="login"/>
<property name="password" column="password" />
<property name="email" column="email" />
</class>
</hibernate-mapping>
this is my user entity
public class User {
private int id;
private String login;
private String password;
private String email;
public User(){
}
public User(String login, String password, String email){
this.login = login;
this.password = password;
this.email = email;
}
public int getId(){
return id;
}
public String getLogin(){
return login;
}
public String getPassword(){
return password;
}
public String getEmail(){
return email;
}
public void setId(int id){
this.id = id;
}
public void setLogin(String login){
this.login = login;
}
public void setPassword(String password){
this.password = password;
}
public void setEmail(String email){
this.email = email;
}
}
when i try save db in this way "hibernateTemplate.save(user)' i catch in console this line
"Hibernate: insert into users (login, password, email) values (?, ?, ?)" and changes don't save into database. I tried in user.hbn.xml change generator class to "increment" because my id in data base table has AUTO INCREMENT parameter, but it doesn't work.
This sound like your transaction didn't get commit after update. When you call HibernateTemplate.update() it only update your persistent but doesn't actually to commit those changes. Remember to always conclude your transaction and save it before moving on.
Here are some resources on hibernate sessions and transactions that might help you with your current problem 1 and 2
xml file to map a new table from my db but when I start the project I get a Duplicate property mapping error that I cannot understand and resolve. Here is my hibernate cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory name="session1">
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.password"/>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/realestate</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
<property name="hibernate.connection.CharSet">utf8</property>
<property name="hibernate.connection.characterEncoding">utf8</property>
<property name="hibernate.connection.useUnicode">true</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.format_sql">true</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.max_size">20</property>
<property name="hibernate.c3p0.timeout">300</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.idle_test_period">3000</property>
<property name="hibernate.connection.CharSet">utf8</property>
<property name="hibernate.connection.characterEncoding">utf8</property>
<property name="hibernate.connection.useUnicode">true</property>
<mapping resource="entities/users.hbm.xml"/>
<mapping resource="entities/adminstration.hbm.xml"/>
<mapping resource="entities/seller.hbm.xml"/>
<mapping resource="entities/buyer.hbm.xml"/>
<mapping resource="entities/renter.hbm.xml"/>
<mapping resource="entities/leeser.hbm.xml"/>
<mapping resource="entities/house.hbm.xml"/>
<mapping resource="entities/userSellsHouse.hbm.xml"/>
<mapping resource="entities/userRentsHouse.hbm.xml"/>
<mapping resource="entities/messages.hbm.xml"/>
</session-factory>
</hibernate-configuration>
The messages.hbm.xml file:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="entities.Message" table="MESSAGES" schema="realestate">
<id name="messageID" type="int">
<column name="messsageID" />
</id>
<property name="Date" type="java.lang.String">
<column name="Date" />
</property>
<property name="SenderID" type="java.lang.Integer">
<column name="Sender" />
</property>
<property name="ReceiverID" type="java.lang.Integer">
<column name="Receiver" />
</property>
<property name="Message" type="java.lang.String">
<column name="Message" />
</property>
<property name="Theme" type="java.lang.String">
<column name="Theme" />
</property>
</class>
</hibernate-mapping>
and the Message persisent class:
public class Message {
int MessageID;
int SenderID;
int ReceiverID;
String date;
String message;
String theme;
public int getMessageID() {
return MessageID;
}
public void setMessageID(int messageID) {
MessageID = messageID;
}
public int getSenderID() {
return SenderID;
}
public void setSenderID(int senderID) {
SenderID = senderID;
}
public int getReceiverID() {
return ReceiverID;
}
public void setReceiverID(int receiverID) {
ReceiverID = receiverID;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public String getTheme() {
return theme;
}
public void setTheme(String theme) {
this.theme = theme;
}
}
and here's the error
...
Caused by: org.hibernate.MappingException: Duplicate property mapping of SenderID found in entities.Messages
at org.hibernate.mapping.PersistentClass.checkPropertyDuplication(PersistentClass.java:515)
at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:505)
at org.hibernate.mapping.RootClass.validate(RootClass.java:270)
at org.hibernate.cfg.Configuration.validate(Configuration.java:1358)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1849)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1928)
at database.HibernateUtil.<clinit>(HibernateUtil.java:15)
... 46 more
Edit: I tried commenting out the <mapping resource="entities/messages.hbm.xml"/> from the cfg file and I still get the same error.
Edit2: The above is from a java EE project, I copied paste everything in a simle java project and it worked fine. Any suggestion?
Edit3: I added the final modifier to messages class to be sure that it cannot be inherited
Please go through the following link, this might help you...
Hibernate ORMHHH-2598
Mapping a collection of entities from two different classes with the same collection name results in duplicate backref property exception if collection keys are not null
I have been trying to make a table automatically with hibernate. Tried all the solutions given for the same question. Please have a look and point out what is wrong. I am using it with MySQL 5.6 version.
public class Tester
{
public static void main(String[] args)
{
SessionFactory factory = new Configuration().configure("com/hibernate.hbm.xml").buildSessionFactory();
System.out.println(factory.toString() + " - DONE");
}
}
Product class is :
public class Product
{
private String product;
private String productName;
public String getProduct()
{
return product;
}
public void setProduct(String product)
{
this.product = product;
}
public String getProductName()
{
return productName;
}
public void setProductName(String productName)
{
this.productName = productName;
}
}
My hbm file looks like this :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com">
<class name="Product" table="product_table">
<id name="product" column="product_id" type="java.lang.String" length="20" >
<generator class="assigned" />
</id>
<property name="productName" column="product_name" type="java.lang.String" length="50" not-null="true" />
</class>
</hibernate-mapping>
And hibernate.cfg.xml is given below -
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/caching_hibernate</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">root</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<property name="hibernate.show_sql">true</property>
<property name="cache.providerclass">org.hibernate.NoCacheProvider</property>
<mapping resource="com/product.hbm.xml" />
</session-factory>
</hibernate-configuration>
Program shows no exception and runs normally..Thanks in advance