Hi,

I'm running into a problem that occurs occassionally when I run my tests.

I have 2 classes, User and LoggedInUser.

LoggedInUser extends User. It is essentially exactly the same as User but has a few extra methods such as Privileges.

At the moment I created a Hibernate Mapping file for both classes and depending on which one I want to return I call 1 or the other.

However, sometimes when I have already returned a loggedInUser and then try and return a User it results in a WrongClassCastException stating it is not of Type LoggedInUser.

Both mapping files or exactly the same.

I have read through how I am advised to deal with inheritance in Hibernate in Action but it doesn't seem to really cater for what I am trying to do. I can't put a descriminator column in as I don't not whether they are logged in or not until I check that their password is correct.

Anyone have any experience of how to solve this?

Post the requested information please. It's very hard to guess what your code might be doing.

Right, some more info.

I have gone for a slightly differenet approach. I now only have one mapping file for User. (see below for the file) When a User logins in a return a User object using the mapping file and then create a LoggedInUser object with the User data and the additional fields I need to populate.

That all works fine but I run into a problem a bit further down the line. At any point, and part of the application can get the LoggedInUser object by calling UserService.getCurrentUser().

If the try and save this object, it obviously complains that there is no mapping file associated with LoggedInUser. If I do have a mapping file associated with LoggedInUser then I get many other ClassCastExceptions in other places.

Is there a good way of designing a solution to this problem so that I Hibernate knows that LoggedInUser object is actually a User object and to save that in the database?

Hibernate Version
--------------------------------
3.0.5

User.hbm.xml
--------------------------------------------------------------


<?xml version="1.0"?>

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

<hibernate-mapping>
<class
name="uk.gov.ch.chips.common.user.User"
table="USER_ACCESS"
dynamic-update="false"
dynamic-insert="false"
>

<id name="id"
column="USER_ACCESS_ID"
type="java.lang.Long"
access="field">
<generator class="assigned" />
</id>

<property name="loginId"
column="LOGIN_ID"
type="string"
access="field"
length="30"
not-null="true"
/>

<property name="firstName"
column="USER_FORENAME"
type="string"
access="field"
length="50"
/>

<property name="lastName"
column="USER_SURNAME"
type="string"
access="field"
length="160"
/>

<property name="emailAddress"
column="USER_EMAIL"
type="string"
access="field"
length="256"
/>

<property name="telExt"
column="USER_TELEPHONE_NO"
type="string"
access="field"
/>

<property
name="locked"
type="yes_no"
update="true"
insert="true"
access="property"
column="Locked_IND"
length="1"
not-null="true"
/>

<property name="loginFailureCount"
column="LOGIN_FAILURE_COUNT"
type="int"
update="true"
insert="true"
access="property"
length="4"
not-null="true"
/>

<property
name="customStyleSheet"
column="CUSTOM_STYLESHEET"
type="string"
access="field"
length="64"
/>


<property
name="effectiveDate"
type="java.util.Date"
access="field"
column="USER_EFF_DATE"
length="10"
not-null="true"
/>

<property
name="endDate"
type="java.util.Date"
access="field"
column="USER_END_DATE"
length="10"
not-null="true"
/>

<property
name="tdfStart"
column="TDF_START"
type="java.lang.Integer"
access="field"
length="3"
/>

<property
name="tdfEnd"
column="TDF_END"
type="java.lang.Integer"
access="field"
length="3"
/>

<many-to-one name="homeOrgUnit"
class="uk.gov.ch.chips.common.user.OrgUnit"
access="field">
<column
name="ORGANISATIONAL_UNIT_ID"
/>
</many-to-one>

<list name="userPrivileges"
table="USER_PRIVILEGE"
lazy="true"
inverse="true"
access="field">
<key column="USER_ACCESS_ID" />
<index column="USER_PRIVILEGE_ID" />
<many-to-many class="uk.gov.ch.chips.common.user.Privilege"
column="PRIVILEGE_TYPE_ID" />
</list>

<list name="userGroups"
table="USERACC_GROUPACC_LINK"
lazy="true"
inverse="true"
access="field"
cascade="save-update">
<key column="USER_ACCESS_ID" />
<index column="USER_GROUPACC_LINK_ID" />
<many-to-many class="uk.gov.ch.chips.common.user.Group"
column="GROUP_ACCESS_ID" />
</list>

</class>

</hibernate-mapping>

Sorry, forgot to include stack trace
------------------------------------------------

net.sf.hibernate.MappingException: No persister for: uk.gov.ch.chips.common.user.LoggedInUser
at net.sf.hibernate.impl.SessionFactoryImpl.getPersister(SessionFactoryImpl.java:347)
at net.sf.hibernate.impl.SessionImpl.getClassPersister(SessionImpl.java:2690)
at net.sf.hibernate.impl.SessionImpl.getPersister(SessionImpl.java:2697)
at net.sf.hibernate.impl.SessionImpl.isUnsaved(SessionImpl.java:1091)
at net.sf.hibernate.impl.SessionImpl.nullifyTransientReferences(SessionImpl.java:1037)
at net.sf.hibernate.impl.SessionImpl.nullifyTransientReferences(SessionImpl.java:1023)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:927)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:857)
at net.sf.hibernate.impl.SessionImpl.saveWithGeneratedIdentifier(SessionImpl.java:779)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:738)
at uk.gov.ch.chips.server.mis.MisServiceDaoTest.setUp(MisServiceDaoTest.java:56)
at junit.framework.TestCase.runBare(TestCase.java:125)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:474)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:342)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:194)

1.) I don't understand what to say against LoggedInUser extends User and using a subclass in the mapping, for example.

2.) I think wouldn't design it this way. Why don't you take a user which has an additional attribute "loggedIn" (boolean)? Your application then checks whether any user method can be called or not - depending on the attribute "loogedIn".

3.) You're using the wrong DTD with your version of Hibernate. You the following instead:



Best regards
Sven

Unfortunatly the application is already at an advanced stage and the design of how LoggedInUser and User works can't be changed or that idea would have worked.

Upon further investigation I realise that we are actually not using the 3.0.5 but Hibernate 2, I was told we were using the latest version but that turned out to be rubbish!

I thought to put LoggedInUser as a subclass of User in the mapping file I would need some kind of descriminator in the database table? Is this not so?

Can you give me an example of what I put in the mapping file. Everything I put in seems to make my mapping file invalid. i.e.

<subclass name="...LoggedInUser" (What else do I need to put in here?)

Many thanks

Of course you need a discriminator using table per class hierarchy strategy (<subclass>).

You can find examples and more information here:
http://www.hibernate.org/hib_docs/v3/re ... nheritance

You will also find information about the other inheritance strategies.

Best regards
Sven