Hello Guys,
I am trying to build a relatively simple application on Google App Engine. I
am trying to use JDO to build my datalayer and am running into a load of
issues. I am very new to JDO so these might be newbie issues, but I cant
seem to proceed past this.
The problem is that when i try to access an object via getObjectByID and I
create a User key to pass to the function, I was getting different errors at
different times.
1. Error while trying to convert <stringified primary key object> into
internal key
2. Object not found
The detailed steps I performed are as follows:
1. Created a New Google App Engine Project
2. Created a new Entity: User (Code attached) (fields: firstName, lastName,
emailID)
3. Created a primaryKey: UserPK (on emailID ) // I know that i could use the
default key, but i need to do this way
4. Stored it vi
User user = new User(....., "t...@example.com");
pm.makePersistent(user)
5. Trying to access it by: UserPK pk = new
UserPK("com.basildsouza.odometer.datalayer.dataobjects.User$
UserPK::t...@example.com <userpk%3a%3at...@example.com>")
pm.getObjectById(pk) // This doesnt work, was initially giving my error 1
(see above) and now gives me error 2
Also when i run a query like select from ...User where emailID=
t...@example.com, it does find the value properly, so i am at a loss as to
why the getObjectById isnt working.
Also, when i do pm.deletePersistant on an object i got via my above query, i
get an error saying that the primary key is null.
What i have understood from this, is that for some reason the primary key
isnt getting set for the user object. But i dont know why.
Please Help!
Code Attached:
User.java (with the UserPK as an inner static class) (Pardon the mess :)
jdoconfig.xml (generated by google)
--
Regards,
Basil Dsouza
http://www.basildsouza.com
<?xml version="1.0" encoding="utf-8"?>
<jdoconfig xmlns="http://java.sun.com/xml/ns/jdo/jdoconfig";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:noNamespaceSchemaLocation="http://java.sun.com/xml/ns/jdo/jdoconfig";>
<persistence-manager-factory name="transactions-optional">
<property name="javax.jdo.PersistenceManagerFactoryClass"
value="org.datanucleus.store.appengine.jdo.DatastoreJDOPersistenceManagerFactory"/>
<property name="javax.jdo.option.ConnectionURL" value="appengine"/>
<property name="javax.jdo.option.NontransactionalRead" value="true"/>
<property name="javax.jdo.option.NontransactionalWrite" value="true"/>
<property name="javax.jdo.option.RetainValues" value="true"/>
<property name="datanucleus.appengine.autoCreateDatastoreTxns" value="true"/>
</persistence-manager-factory>
</jdoconfig>
