I've written an application that record details about machines, each each machine having many fields composed of complex types such as MachineType etc. I've included the mapping file to see what the class would contain.

I'm having a problem when I try to query the database for all machines in the DB, I'm getting a SerializationException caused by an EOFException (see stack trace below). Does this ring a bell with any users? Am I breaking a mapping rule that manifests itself this way? Any help would be greatly appreciated because everything looks correct on the surface and all of the other mappings work correctly. I'm thinking that I have perhaps put in a circular reference which never completes so it decides to bomb out instead :(

This is happening with Hibernate 2.1.4, JDK 1.4.2, MySQL 4.0

Mapping document

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping package="xxxxxxx">
<class name="Machine" table="machine">
<id
name="id"
type="java.lang.Integer"
column="id"
>
<generator class="native"/>
</id>

<property
name="dateManufactured"
column="date_of_manufactured"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>
<property
name="manufarturerName"
column="manufarturer_name"
type="java.lang.String"
not-null="false"
length="40"
/>
<property
name="maintFrequencyWeeks"
column="maint_frequency_weeks"
type="java.lang.Integer"
not-null="true"
length="4"
/>
<property
name="hardwareNotes"
column="hardware_notes"
type="java.lang.String"
not-null="false"
/>
<property
name="maintStartDate"
column="maint_start_date"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>
<property
name="dateLastService"
column="date_last_service"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>
<property
name="softwareVersion"
column="software_version"
type="java.lang.String"
not-null="false"
length="20"
/>
<property
name="keyNumber1"
column="key_number1"
type="java.lang.String"
not-null="false"
length="20"
/>
<property
name="keyNumber3"
column="key_number3"
type="java.lang.String"
not-null="false"
length="20"
/>
<property
name="warrantyExpiryDate"
column="warranty_expiry_date"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>
<property
name="contractExpiryDate"
column="contract_expiry_date"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>
<property
name="location"
column="location"
type="java.lang.String"
not-null="false"
length="60"
/>
<property
name="manufSerialNumber"
column="manuf_serial_number"
type="java.lang.String"
not-null="false"
length="25"
/>
<property
name="dateLastTicketed"
column="date_last_ticketed"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>
<property
name="region"
column="region_id"
type="ie.uts.Region"
not-null="true"
length="10"
/>

<property
name="numbered"
column="numbered"
type="java.lang.Integer"
not-null="false"
length="1"
/>
<property
name="keyNumber2"
column="key_number2"
type="java.lang.String"
not-null="false"
length="20"
/>
<property
name="description"
column="description"
type="java.lang.String"
not-null="false"
length="40"
/>
<property
name="model"
column="model"
type="java.lang.String"
not-null="false"
length="40"
/>
<property
name="ourMachineNumber"
column="our_machine_number"
type="java.lang.String"
not-null="false"
length="20"
/>
<property
name="dateInstalled"
column="date_installed"
type="java.sql.Timestamp"
not-null="false"
length="14"
/>

<many-to-one
name="machineType"
class="MachineType"
not-null="true"
>
<column name="machine_type_id" />
</many-to-one>

<many-to-one
name="tariffSet"
class="Tariff"
not-null="true"
>
<column name="tariff_set" />
</many-to-one>

<many-to-one
name="customer"
class="Customer"
not-null="true"
>
<column name="customer" />
</many-to-one>

<many-to-one
name="contractType"
class="ContractType"
not-null="true"
>
<column name="contract_type" />
</many-to-one>
</class>

</hibernate-mapping>

Stack trace
02-Aug-2004 20:42:19 net.sf.hibernate.impl.SessionImpl finalize
WARNING: unclosed connection
net.sf.hibernate.type.SerializationException: could not deserialize
at net.sf.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:197)
at net.sf.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:220)
at net.sf.hibernate.type.SerializableType.fromBytes(SerializableType.java:73)
at net.sf.hibernate.type.SerializableType.get(SerializableType.java:38)
at net.sf.hibernate.type.NullableType.nullSafeGet(NullableType.java:62)
at net.sf.hibernate.type.NullableType.nullSafeGet(NullableType.java:53)
at net.sf.hibernate.type.AbstractType.hydrate(AbstractType.java:66)
at net.sf.hibernate.loader.Loader.hydrate(Loader.java:611)
at net.sf.hibernate.loader.Loader.loadFromResultSet(Loader.java:552)
at net.sf.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:511)
at net.sf.hibernate.loader.Loader.getRow(Loader.java:426)
at net.sf.hibernate.loader.Loader.doQuery(Loader.java:209)
at net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:133)
at net.sf.hibernate.loader.Loader.doList(Loader.java:955)
at net.sf.hibernate.loader.Loader.list(Loader.java:946)
at net.sf.hibernate.loader.CriteriaLoader.list(CriteriaLoader.java:121)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:3609)
at net.sf.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:238)
at common.dao.HibernateDAO.findByCriteria(HibernateDAO.java:885)
at common.delegate.GenericDelegate.findByCriteria(GenericDelegate.java:49)
at common.taglib.ListTag.doEndTag(ListTag.java:50)
at org.apache.jsp.login.view_005fmachines_jsp._jspx_meth_db_list_0(view_005fmachines_jsp.java:156)
at org.apache.jsp.login.view_005fmachines_jsp._jspService(view_005fmachines_jsp.java:65)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:133)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:311)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:284)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:204)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:257)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:245)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:199)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:184)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:164)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:156)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:972)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:206)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:833)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:732)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:619)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:688)
at java.lang.Thread.run(Thread.java:534)
Caused by: java.io.EOFException
at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2165)
at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2631)
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:734)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:253)
at net.sf.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:189)
... 52 more

I'm using hibernatesynch to generate the mapping documents and it added one of the fields (region) as a property instead of a many-to-one, remapped and it worked fine.