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POEager loading in Hibernate doesnt work, referenced attrribute has null values
 

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  1. POEager loading in Hibernate doesnt work, referenced attrribute has null values
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    <p>i have a hibernate problem, probably due to lazy/eager loading or something similiar. I have a model class student and a model class century. The student has an attribute century. Before I save the stdent in the dao i save the referenced century. But when I save the student, the century is null everywhere, except for it's name. I tried @Fetch(FetchMode.JOIN), @ManyToOne(fetch = FetchType.EAGER) and getHibernateTemplate().initialize(student.getCentury()); so far but nothing will work. Some ideas would be great, thanks in advance!</p> <p>Student class:</p> <pre><code>// @Fetch(FetchMode.JOIN) @ManyToOne(fetch = FetchType.EAGER) @JoinColumn(name = "CENTURY_ID") public Century getCentury() { return century; } </code></pre> <p>StudentDao:</p> <p>load-method inherited from SuperDao:</p> <pre><code>@SuppressWarnings("unchecked") public T load(Long id) { T object = (T) getSession().get( classOfData, id); log.error(String.format("%s with id %d loaded.", CLASS_NAME_OF_DATA, id)); if (object == null) { log.error("Object not found"); } return object; } </code></pre> <p>save method in StudentDao:</p> <pre><code> @Override public Student save(Student student) throws HibernateException { // getHibernateTemplate().initialize(student.getCentury()); log.error("Saving student:" + student.toString()); Century century = centuryDao.load(student.getCentury().getId()); System.out.println("instudentdao:" + century.getManiple()); centuryDao.save(student.getCentury()); getSession().saveOrUpdate(student); log.error(String.format("Student with id %d saved.", student.getId())); return student; } </code></pre> <p>StudentAction load method is passed down to Dao:</p> <pre><code>private void loadStudent(String id) { create = request.getParameter("mode").equals("create"); edit = request.getParameter("mode").equals("edit"); view = request.getParameter("mode").equals("view"); if (request.getParameter("mode").equals("create")) student = new Student(); else student = studentService.load(Long.valueOf(id)); } </code></pre> <p>log for (fetch = FetchType.EAGER)</p> <pre><code>2013-11-17 13:15:59,819 ERROR http-bio-8080-exec-9 - &lt;Saving student:Student [id=1, firstName=hans, lastName=wurst, gender=null, city=HAMBURG, postalCode=22123, street=SHEMALESTREET, streetNumber=23, company=Company [id=null, name1=OLE, name2=null, nameShort=null, city=null, postalCode=null, street=null, streetNumber=null, email=null, phone=null, fax=null, status=null, supervisors=null], phone=1234123, email=olko@olko.olko, century=Century [id=null, name=Zenturie, maniple=null, students=null], birthday=Sun Jan 01 00:00:00 CET 2012, birthPlace=MUELLTONNE, userId=123, addressAddition=, status=ACTIVE, supervisor=Supervisor [id=null, firstName=null, lastName=, company=null, email=null, phone=null]]&gt; </code></pre> <p>log for @JoinColumn(name = "CENTURY_ID")</p> <pre><code>2013-11-17 13:22:25,266 ERROR http-bio-8080-exec-10 - &lt;Saving student:Student [id=1, firstName=hans, lastName=wurst, gender=null, city=HAMBURG, postalCode=22123, street=SHEMALESTREET, streetNumber=23, company=Company [id=null, name1=OLE, name2=null, nameShort=null, city=null, postalCode=null, street=null, streetNumber=null, email=null, phone=null, fax=null, status=null, supervisors=null], phone=1234123, email=olko@olko.olko, century=Century [id=null, name=Zenturie, maniple=null, students=null], birthday=Sun Jan 01 00:00:00 CET 2012, birthPlace=MUELLTONNE, userId=123, addressAddition=, status=ACTIVE, supervisor=Supervisor [id=null, firstName=null, lastName=, company=null, email=null, phone=null]]&gt; </code></pre> <p>log for initialize()</p> <pre><code>2013-11-17 13:25:01,381 ERROR http-bio-8080-exec-10 - &lt;Saving student:Student [id=1, firstName=hans, lastName=wurst, gender=null, city=HAMBURG, postalCode=22123, street=SHEMALESTREET, streetNumber=23, company=Company [id=null, name1=OLE, name2=null, nameShort=null, city=null, postalCode=null, street=null, streetNumber=null, email=null, phone=null, fax=null, status=null, supervisors=null], phone=1234123, email=olko@olko.olko, century=Century [id=null, name=Zenturie, maniple=null, students=null], birthday=Sun Jan 01 00:00:00 CET 2012, birthPlace=MUELLTONNE, userId=123, addressAddition=, status=ACTIVE, supervisor=Supervisor [id=null, firstName=null, lastName=, company=null, email=null, phone=null]]&gt; </code></pre>
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    1. PTQuestion
    1. USolkoza
    1. USolkoza
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COS, you're calling this method with a Student whose century only has its name initialized. The (main) problem is not in this method, but in the code that calls this method. How do you create the student and its century before calling this method?
      singulars
      1. POEager loading in Hibernate doesnt work, referenced attrribute has null values
      1. USJB Nizet
    2. COThe StudentDao inherits from a generic SuperDao: `@SuppressWarnings("unchecked") public T load(Long id) { T object = (T) getSession().get( classOfData, id); log.error(String.format("%s with id %d loaded.", CLASS_NAME_OF_DATA, id)); if (object == null) { log.error("Object not found"); } return object; }`
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      1. POEager loading in Hibernate doesnt work, referenced attrribute has null values
      1. USolkoza
    3. COYes, so what? Where is the code that creates the student and its century, and then calls the save method?
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      1. POEager loading in Hibernate doesnt work, referenced attrribute has null values
      1. USJB Nizet
 

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