Hi everyone,
i have a problem using dynamic proxies in a multiuser enviroment. Assume
that client A has a unmaterialized proxy P for the persistent object
Person. The Person got deleted by client B. When client A tries to
access the proxy P a NullPointerException will be thrown. The tests
succeed with only one client and dynamic proxies and also for multiple
clients without dynamic proxies.
The behaviour is similar when a person's address has been deleted, e.g.
assume again that client A has an unmaterialized Proxy of a Person
object. Client B deletes an address object of the Person object
referenced by the unmaterialized Proxy of Client A. If client A executes
a statement like broker.delete(person) a NullPointerException will be
thrown by trying to access the unmaterialized proxy of the deleted
Address object.
The reason of this failures is obvious (the proxy tries to materialize a
non existent object) but I am not sure if OJB should handle this
situation, or if I have to manualy examine for every proxy if its real
object got deleted. Any help will be appreciated.
I am using tha PB API (rc2), per broker cache and user repository xml
file as follows:
<!-- ############################################### -->
<!-- ########## Address class dercription ########## -->
<!-- ############################################### -->
<class-descriptor class="com.roxes.store.sample.Address">
<extent-class class-ref="com.roxes.store.sample.AddressImpl" />
</class-descriptor>
<class-descriptor class="com.roxes.store.sample.AddressImpl"
table="address" proxy="dynamic">
<!-- ############################# -->
<!-- ##### field descriptors ##### -->
<!-- ############################# -->
<field-descriptor id="1"
name="id"
column="ADDRESS_ID"
jdbc-type="VARCHAR"
autoincrement="true"
primarykey="true"
/>
<field-descriptor id="2"
name="personId"
column="PERSON_ID"
jdbc-type="VARCHAR"
/>
<field-descriptor id="3"
name="streetName"
column="STREET"
jdbc-type="VARCHAR"
/>
<field-descriptor id="4"
name="city"
column="CITY"
jdbc-type="VARCHAR"
/>
<field-descriptor id="5"
name="country"
column="COUNTRY"
jdbc-type="VARCHAR"
/>
<field-descriptor id="6"
name="postcode"
column="POSTCODE"
jdbc-type="VARCHAR"
/>
<field-descriptor id="7"
name="isPrivate"
column="PRIVATE"
jdbc-type="BIT"
/>
<field-descriptor id="8"
name="email"
column="EMAIL"
jdbc-type="VARCHAR"
/>
<field-descriptor id="9"
name="telephoneNumber"
column="TELEPHONE"
jdbc-type="VARCHAR"
/>
<!-- ############################################# -->
<!-- ##### foreign key reference definitions ##### -->
<!-- ############################################# -->
<reference-descriptor
name="person"
class-ref="com.roxes.store.sample.PersonImpl"
refesh="true"
>
<foreignkey field-id-ref="2"/>
</reference-descriptor>
</class-descriptor>
<!-- ############################################## -->
<!-- ########## Person class description ########## -->
<!-- ############################################## -->
<class-descriptor class="com.roxes.store.sample.Person">
<extent-class class-ref="com.roxes.store.sample.PersonImpl" />
</class-descriptor>
<class-descriptor class="com.roxes.store.sample.PersonImpl"
table="person" proxy="dynamic">
<field-descriptor id="1"
name="id"
column="PERSON_ID"
jdbc-type="VARCHAR"
autoincrement="true"
primarykey="true"
/>
<field-descriptor id="2"
name="forename"
column="FORENAME"
jdbc-type="VARCHAR"
/>
<field-descriptor id="3"
name="surname"
column="SURNAME"
jdbc-type="VARCHAR"
/>
<field-descriptor id="4"
name="birthday"
column="BIRTHDAY"
jdbc-type="DATE"
/>
<field-descriptor id="5"
name="email"
column="EMAIL"
jdbc-type="VARCHAR"
/>
<field-descriptor id="6"
name="mobileTelephoneNumber"
column="MOBILE"
jdbc-type="VARCHAR"
/>
<collection-descriptor
name="addresses"
element-class-ref="com.roxes.store.sample.AddressImpl"
auto-retrieve="true"
auto-delete="true"
refresh="true"
>
<fk-pointing-to-this-class column="PERSON_ID"/>
<fk-pointing-to-element-class column="ADDRESS_ID"/>
</collection-descriptor>
</class-descriptor>
This is the exception trace
java.lang.NullPointerException
at
org.apache.ojb.broker.singlevm.PersistenceBrokerImpl.delete(Unknown
Source)
at
org.apache.ojb.broker.singlevm.PersistenceBrokerImpl.deleteCollections(Unknown Source)
at
org.apache.ojb.broker.singlevm.PersistenceBrokerImpl.delete(Unknown
Source)
at
org.apache.ojb.broker.singlevm.DelegatingPersistenceBroker.delete(Unknown Source)
at
com.roxes.store.ojb.PBResourceManager.delete(PBResourceManager.java:171)
at com.roxes.store.ojb.OJBStore.delete(OJBStore.java:217)
at
com.roxes.store.sample.AddressBook.remove(AddressBook.java:172)
at
com.roxes.store.sample.test.AddressBookTestCase.testRemove(AddressBookTestCase.java:126)
at
com.roxes.store.sample.test.AddressBookTestCase.runTest(AddressBookTestCase.java:48)
at junit.framework.TestCase.runBare(TestCase.java:140)
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:131)
at
junit.extensions.ActiveTestSuite$1.run(ActiveTestSuite.java:26)
rethrown as org.apache.ojb.broker.PersistenceBrokerException
at
org.apache.ojb.broker.singlevm.PersistenceBrokerImpl.deleteCollections(Unknown Source)
at
org.apache.ojb.broker.singlevm.PersistenceBrokerImpl.delete(Unknown
Source)
at
org.apache.ojb.broker.singlevm.DelegatingPersistenceBroker.delete(Unknown Source)
at
com.roxes.store.ojb.PBResourceManager.delete(PBResourceManager.java:171)
at com.roxes.store.ojb.OJBStore.delete(OJBStore.java:217)
at
com.roxes.store.sample.AddressBook.remove(AddressBook.java:172)
at
com.roxes.store.sample.test.AddressBookTestCase.testRemove(AddressBookTestCase.java:126)
at
com.roxes.store.sample.test.AddressBookTestCase.runTest(AddressBookTestCase.java:48)
at junit.framework.TestCase.runBare(TestCase.java:140)
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:131)
at
junit.extensions.ActiveTestSuite$1.run(ActiveTestSuite.java:26)
Caused by: java.lang.NullPointerException
at
org.apache.ojb.broker.singlevm.PersistenceBrokerImpl.delete(Unknown
Source)
... 14 more
Thanks in advance,
Nikos
--
Nikos Vitalis <[EMAIL PROTECTED]>
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