hbm2java crashing with generics enabled - with a fix!

vsimkus · **Posted:** Thu Aug 04, 2005 9:58 pm

Hi

I am (was) having a weird promblem with the hbm2java ant task. I tried looking for info on the web, but found nothing. I'm a complete newby at Hibernate, so if any of this is old news to people, I appologise.

The problem is that the ant task (hbm2java) was crashing while processing the following snippet:

Code:

<class name="patient" table="patient">
      <id name="patientID" type="int" >
         <generator class="sequence" />
      </id>
      <property name="firstName" type="string" length="64" not-null="true" />
      <property name="lastName" type="string" length="64" not-null="true" />
      <property name="medRecNum" type="string" length="64" not-null="true" />
      <property name="dob" type="date" not-null="true" />
      <property name="heightFt" type="int" not-null="true" />
      <property name="heightIn" type="int" not-null="true" />
      <set name="visits">
         <key column="patientID" />
         <many-to-many column="visitID" unique="true" class="visit" />
      </set>
   </class>
   <class name="visit" table="visit" >
      <id name="visitId" column="visitiId" type="int" >
         <generator class="sequence" />
      </id>
   </class>

It was failing with a class cast exception:

Code:

[hibernatetool] java.lang.ClassCastException: org.hibernate.mapping.ManyToOne
[hibernatetool]         at org.hibernate.tool.hbm2x.Cfg2JavaTool.getRawTypeName(Cfg2JavaTool.java:594)
[hibernatetool]         at org.hibernate.tool.hbm2x.Cfg2JavaTool.getJavaTypeName(Cfg2JavaTool.java:494)
[hibernatetool]         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[hibernatetool]         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

I tried applying this http://opensource.atlassian.com/projects/hibernate/browse/HBX-224 . No luck. After digging arount the latest CVS checkout of HibernateExt, I narrowed the problem to a block of code at approximately line 600 of Cfg2JavaTool.java. There's a line that's trying to cast a variable to a OneToMany.

Code:

OneToMany oneToMany = (OneToMany) collection.getElement();

At runtime though, the variable is of type ManyToOne. Hence the class cast exception. So what I did was check for the variable type.:

Code:

Object temp = collection.getElement();

                            //OneToMany oneToMany = (OneToMany)temp;

                            String entityName = null;

                            if(temp instanceof ManyToOne)
                            {
                                entityName = ((ManyToOne)temp).getReferencedEntityName();
                            }
                            else if(temp instanceof OneToMany)
                            {
                                entityName = ((OneToMany)temp).getReferencedEntityName();
                            }

So umm.... do I get a cookie? :)

Hopefully this will help someone.

Also, how come the patch for another bug http://opensource.atlassian.com/projects/hibernate/browse/HBX-224 is not in CVS?

max · **Posted:** Fri Aug 05, 2005 3:13 am

put a patch in cvs.

why the other bug is not in cvs ? oversight i would assume.

/max

idfrisbie · **Joined:** Wed Sep 14, 2005 3:38 pm **Posts:** 5

I'm getting this same error. Is the resolution to this problem rolled into any distribution? Or is there an older distribution that supports many-to-many without this problem?

Really didn't want to get into modifying source code. Started out with 3.0.1 with this problem and moved to latest (3.1.0). I'm assuming that this worked at some point, do I have to go back to hibernate2?

thx, Ian

max · **Posted:** Wed Sep 14, 2005 4:09 pm

no and many-to-many support is not a toppriority.....would be good if people that has problems with it supply patches.

peace,

idfrisbie · **Joined:** Wed Sep 14, 2005 3:38 pm **Posts:** 5

maybe he assumed that CVS write access was limited to developers. I mis-read your original reply - I thought you said you had put a fix into CVS, didn't realize you were asking him to put one in (maybe he made the same mistake).

max · **Posted:** Thu Sep 15, 2005 1:40 am

ah - i miswrote...should read: Put a patch in Jira

koreth · **Joined:** Thu Feb 12, 2004 6:19 pm **Posts:** 10

For the record, this is not limited to many-to-many mappings. I have no many-to-many mappings and I get the same error -- it also affects many-to-one mappings.