-->
These old forums are deprecated now and set to read-only. We are waiting for you on our new forums!
More modern, Discourse-based and with GitHub/Google/Twitter authentication built-in.

View unanswered posts | View active topics


Board index » Hibernate & Java Persistence » Hibernate Users

All times are UTC - 5 hours [ DST ]


Forum locked This topic is locked, you cannot edit posts or make further replies.  Page 1 of 1
  [ 1 post ] 
  Previous topic | Next topic 
Author Message
pt.forumtech2
 Post subject: I can't access a list after query in a one-to-many relation
PostPosted: Fri Dec 28, 2012 5:28 pm 
Newbie

Joined: Fri Dec 28, 2012 4:55 pm
Posts: 1
Hi,

I have a problem with Hibernate, one-to-many associations and lists. In my model, I have country and, for each country, I have multiple informations who describe a structure for adresses in that country. I want to access the list of these elements.

This my class Country :

Code:
    public class Country {
          
    private Long id;
    private String name;
    private List<AddressElement> addressElementList = null;
    ...
    }


my class AddressElement :

Code:
   
    public class AddressElement {
                   
    private Long id;
    private int pos;
    private int line;
    private String name;
    private String mask;
    ...
    }


and my mappings :

Code:
    <hibernate-mapping  package="org.devtutos.tuto5.domaine">                        
    <class  name="Country" table="tuto.COUNTRY" >
      <id name="id" type="java.lang.Long" column="COUNTRY_ID" unsaved-value="null">      
         <generator class="native">   
            <param name="sequence">tuto.SEQ_COUNTRY</param>
         </generator>
        </id>
        <natural-id mutable="true">
             <property    name="name"  column="COUNTRY_NAME" type="java.lang.String"/>     
        </natural-id>
       <list name="addressElementList" table="tuto.ADDRESS_ELEMENT" lazy="false">
          <key  foreign-key="country_address_element_fk">
             <column name="COUNTRY_ID" not-null="true"/>   
          </key>
          <list-index>
               <column name="ADDRESS_ELEMENT_POS" not-null="true" />
          </list-index>
          <one-to-many class="AddressElement"/>   
       </list>
    </class>
    </hibernate-mapping>

Code:
    <hibernate-mapping  package="org.devtutos.tuto5.domaine">                        
    <class  name="AddressElement" table="tuto.ADDRESS_ELEMENT" >
      <id name="id" type="java.lang.Long" column="ADDRESS_ELEMENT_ID" unsaved-value="null">      
          <generator class="native">   
                <param name="sequence">tuto.SEQ_ADDRESS_ELEMENT</param>
          </generator>
        </id>
        <property name="line" column="ADDRESS_ELEMENT_LINE" not-null="true" type="java.lang.Integer" />
        <property name="name" column="ADDRESS_ELEMENT_NAME" not-null="true" type="java.lang.String" />
        <property name="mask" column="ADDRESS_ELEMENT_TYPE_MASK" not-null="true" type="java.lang.String" />
        <property name="pos" column="ADDRESS_ELEMENT_POS" not-null="true" type="java.lang.Integer" />
    </class>
    </hibernate-mapping>


This my code :

Code:
    criteria = getSessionFactory().getCurrentSession().createCriteria(Country.class);
    criteria.add(Restrictions.eq("name", countryName));
    criteria.setFetchMode("addressElementList",FetchMode.JOIN);
          
    Country country = (Country) criteria.list().get(0);
          
    if (country == null) {
          
       logger.log(Level.INFO, "ERREUR DE COHERENCE INTERNE : Pays '".concat(countryName).concat("'non trouvé:"));
    }
    else {
       logger.log(Level.INFO, "Pays trouvé.");
       logger.log(Level.INFO, "Nom du Pays :".concat(country.getName()));
       logger.log(Level.INFO, "Code du Pays :".concat(String.valueOf(country.getId())));
       liste = country.getAddressElementList();
       logger.log(Level.INFO, "Taille de la liste des éléments d'adresse :".concat(String.valueOf(liste.size())));
       for (AddressElement elem : liste){
          if (elem == null) {logger.log(Level.INFO, "L'élément d'adresse est null.");}
             logger.log(Level.INFO, "Element de la liste : ID = ".concat(String.valueOf(elem.getId())));    **** Line of the error
             logger.log(Level.INFO, "Element de la liste : POS = ".concat(String.valueOf(elem.getPos())));
             logger.log(Level.INFO, "Element de la liste : NOM = ".concat(elem.getName()));
          }
       }
    }


This my log :

Code:
    Hibernate:
    select
    this_.COUNTRY_ID as COUNTRY1_2_1_,
    this_.COUNTRY_NAME as COUNTRY2_2_1_,
    addressele2_.COUNTRY_ID as COUNTRY6_2_3_,
    addressele2_.ADDRESS_ELEMENT_ID as ADDRESS1_3_,
    addressele2_.ADDRESS_ELEMENT_POS as ADDRESS5_3_,
    addressele2_.ADDRESS_ELEMENT_ID as ADDRESS1_0_0_,
    addressele2_.ADDRESS_ELEMENT_LINE as ADDRESS2_0_0_,
    addressele2_.ADDRESS_ELEMENT_NAME as ADDRESS3_0_0_,
    addressele2_.ADDRESS_ELEMENT_TYPE_MASK as ADDRESS4_0_0_,
    addressele2_.ADDRESS_ELEMENT_POS as ADDRESS5_0_0_
    from
    tuto.COUNTRY this_ left outer join tuto.ADDRESS_ELEMENT addressele2_
    on this_.COUNTRY_ID=addressele2_.COUNTRY_ID
    where
    this_.COUNTRY_NAME=?
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Pays trouvé.
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Nom du Pays :FRANCE
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Code du Pays :1
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Taille de la liste des éléments d'adresse :4
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: L'élément d'adresse est null.
    27 déc. 2012 16:19:09 org.apache.catalina.core.StandardWrapperValve invoke
    GRAVE: Servlet.service() for servlet [tuto5] in context with path [/tuto-5] threw exception [Request processing failed; nested exception is org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing [AnnotatedAction@3f610944 targetAction org.devtutos.tuto5.mvc.webflow.action.receptionAction@4dc6bbd3, attributes = map['method' -> 'enregistrerLUtilisateur']] in state 'enregistrerLUtilisateur' of flow 'reception' -- action execution attributes were 'map[[empty]]'] with root cause
    java.lang.NullPointerException
    at org.devtutos.tuto5.dao.CountryHibernate.getCountryByName(CountryHibernate.java:103)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    ...
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)


I can't access the informations of address elements from a country. I tried several things : I turn the lazy mode to "true" and specify a fetch mode with JOIN but it doesn't work. The most surprising is the list is alimented ( there are 4 elements ) and the following code run well ( So, informations in database, setters and getters works ) :

Code:
    logger.log(Level.INFO, "Lecture de tous les éléments d'adresse.");
    criteria = getSessionFactory().getCurrentSession().createCriteria(AddressElement.class);
    liste = criteria.list();
    logger.log(Level.INFO, "Taille de la liste des éléments d'adresse : ".concat(String.valueOf(liste.size())));
    for (AddressElement elem : liste){
       if (elem == null) {logger.log(Level.INFO, "L'élément d'adresse est null.");}
       logger.log(Level.INFO, "Element de la liste : ID = ".concat(String.valueOf(elem.getId())));
       logger.log(Level.INFO, "Element de la liste : POS = ".concat(String.valueOf(elem.getPos())));
       logger.log(Level.INFO, "Element de la liste : NOM = ".concat(elem.getName()));
    }


These is the result of this code :

Code:
    INFO: Lecture de tous les éléments d'adresse.
    Hibernate: select this_.ADDRESS_ELEMENT_ID as ADDRESS1_0_0_, this_.ADDRESS_ELEMENT_LINE as ADDRESS2_0_0_, this_.ADDRESS_ELEMENT_NAME as ADDRESS3_0_0_, this_.ADDRESS_ELEMENT_TYPE_MASK as ADDRESS4_0_0_, this_.ADDRESS_ELEMENT_POS as ADDRESS5_0_0_ from tuto.ADDRESS_ELEMENT this_
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Taille de la liste des éléments d'adresse : 6
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : ID = 1
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : POS = 1
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : NOM = Code Postal
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : ID = 2
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : POS = 2
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : NOM = Ville
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : ID = 3
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : POS = 3
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : NOM = Batiment
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : ID = 4
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : POS = 1
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : NOM = District
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : ID = 5
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : POS = 2
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : NOM = Zone
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : ID = 6
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : POS = 1
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName
    INFO: Element de la liste : NOM = City
    27 déc. 2012 16:19:09 org.devtutos.tuto5.dao.CountryHibernate getCountryByName


I notice in my first execution that the size of my list is wrong ( 4 in place of 3 ). In my example, the value of countryName is "FRANCE". This is the content of my tables :


COUNTRY :

Code:
    COUNTRY_ID   CONTRY_NAME
    1            "FRANCE"
    2            "HYPERION"
    3            "ATLANTIS"


ADDRESS_ELEMENT :

Code:
    ADDRESS_ELEMENT_ID   COUNTRY_ID    ADDRESS_ELEMENT_POS    ADDRESS_ELEMENT_NAME    ADDRESS_ELEMENT_MASK  ADDRESS_ELEMENT_LINE
    1                     1            1                      "Code Postal"           "\d{5}"               1   
    2                     1            2                      "Ville"                 "[A-Z\-]{1,50}"       1
    3                     1            3                      "Batiment"              "[A-F]"               1
    4                     2            1                      "District"              "[A-Z]{1,20}"         1
    5                     2            2                      "Zone"                  "[A-5]{1,5}"          2
    6                     3            1                      "City"                  "[A-Z]{1,9}"          1


Where am I wrong? I don't understand why "elem" is null in the first execution. Can somebody help me?

Thanks by advance.

Have a good year. ;-)
Top
 Profile  
 
Display posts from previous:  Sort by  
Forum locked This topic is locked, you cannot edit posts or make further replies.  Page 1 of 1
  [ 1 post ] 

Board index » Hibernate & Java Persistence » Hibernate Users

All times are UTC - 5 hours [ DST ]

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
© Copyright 2014, Red Hat Inc. All rights reserved. JBoss and Hibernate are registered trademarks and servicemarks of Red Hat, Inc.