http://www.mail-archive.com/[EMAIL PROTECTED]/msg03320.html
HTH, Gus
Sebastian Muench wrote:
I changed that, but still no result. :-/ It reports "can't access class member with modifiers 'public'" and still the "can't intanciate class, may be no constructor is available".
I really don't know what to do anymore.
-----Urspr�ngliche Nachricht----- Von: Gus Heck [mailto:[EMAIL PROTECTED] Gesendet: Donnerstag, 18. Dezember 2003 21:20 An: OJB Users List Betreff: Re: AW: JDO - Unable to build object instance
It might be because you havn't followed the javabean get/set pattern...
you wrote:
public String GetName() { public void SetName(String name) {
but the standard pattern is
public String getName() { public void setName(String name) {
This probably causes the enhancer to not recognize your object as having any properties to enhance or some such.
- Gus
Sebastian Muench wrote:
Hi all,
yes, I have the default public constructor. May it be, I missed some settings? I did: - the mapping in the Person.jdo (copied to target/classes/JDOTest/) - the mapping in the repository_jdo.xml (in target/test/ojb/) - the schema - creation in the hsqldb
The build and enhance of the class is successful. See more complete source code below.
Thanks for help, Sebastian
package JDOTest;Person.class <<<<<<<<<<<<<<<<<<<<<<<
import java.io.Serializable;
public class Person implements Serializable {
private int id; protected String name;
public Person() {
}
public Person(int id, String name) { this.id = id; this.name = name; }
public int GetId() { return this.id; }
public String GetName() { return this.name; }
public void SetId(int id) { this.id = id; }
public void SetName(String name) { this.name = name; }
}
...TestJdo.class <<<<<<<<<<<<<<<<<<<<<<<
public class TestJdo {
private PersistenceManagerFactory factory; private PersistenceManager manager;
public TestJdo() {
factory = null; manager = null;
try { factory = new OjbStorePMF(); manager = factory.getPersistenceManager(); } catch(Throwable t) { System.out.println(t.getMessage()); t.printStackTrace(); }
}
...
private void run() {
Person p = new Person();
try { PersistenceBrokerFactory.defaultPersistenceBroker().clearCache(); this.manager.currentTransaction().begin(); Query query = this.manager.newQuery(Person.class);
Collection allPerson = (Collection)query.execute();
Iterator iter = allPerson.iterator(); if(!iter.hasNext()) { System.out.println("No entries found"); }
while(iter.hasNext()) { System.out.println(iter.next()); }
manager.currentTransaction().commit(); } catch(Throwable t) { t.printStackTrace(); }
finally { manager.close(); }
}
}
-----Urspr�ngliche Nachricht----- Von: Brian McCallister [mailto:[EMAIL PROTECTED] Gesendet: Mittwoch, 17. Dezember 2003 18:34 An: OJB Users List Betreff: Re: JDO - Unable to build object instance
It doesn't outside of JDO at least, I use private no-arg constructors with OJB all the time.
-Brian
On Wed, 2003-12-17 at 12:18, Gus Heck wrote:
Mahler Thomas wrote:
Hi Sebastian,From _Core Java Data Objects_ page 51:
Does your class have a public default constructor?
"There is one requirement, however; JDO requires that a persistence-capable class have a no-arguments constructor. This constructor does not need to be declared public it just needs to be accessible to the class itself and to any potential subclasses. If thee are no sublcasses it can be declared as private."
Does OJB place a further restriction that it must be public?
-Gus
-----Original Message----- From: Sebastian Muench [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 17, 2003 1:42 AM To: OJB Users List; [EMAIL PROTECTED] Subject: R: JDO - Unable to build object instance
Oh, the file I mentioned in my last mail hasn't been attached. Here is the screenshot:
[JDO] DEBUG: OjbStoreConnector.begin: connectionReadyForRelease=false [org.apache.ojb.broker.accesslayer.RsIterator] ERROR: Error while iterate ResultSet for query org.apache.ojb.broker.accesslayer.RsQueryObject[query: Query from class JDOTest.Person where null, class descriptor: JDOTest.Person] Unable to build object instance (MAYBE you don't have a constructor available):class JDOTest.Person org.apache.ojb.broker.PersistenceBrokerException: Unable to build object instance (MAYBE you don't have a constructor available):class JDOTest.Person at org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl.buildWi thReflection(R owReaderDefaultImpl.java:239) at org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl.readObj ectFrom(RowRea derDefaultImpl.java:115) at org.apache.ojb.broker.accesslayer.RsIterator.getObjectFromResu ltSet(RsIterat or.java:463) at org.apache.ojb.broker.accesslayer.RsIterator.next(RsIterator.java:284) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:147) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:244) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:263) at org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollection ByQuery(Persis tenceBrokerImpl.java:997) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getColl ectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getColl ectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.jdori.sql.OjbExtent.<init>(OjbExtent.java:98) at org.apache.ojb.jdori.sql.OjbStoreManager.getExtent(OjbStoreMan ager.java:251) at com.sun.jdori.common.PersistenceManagerImpl.getExtent(Unknown Source) at com.sun.jdori.common.query.QueryImpl.checkCandidates(Unknown Source) at com.sun.jdori.common.query.QueryImpl.execute(Unknown Source) at JDOTest.TestJdo.run(TestJdo.java:52) at JDOTest.TestJdo.main(TestJdo.java:39) Caused by: org.apache.ojb.broker.metadata.ClassNotPersistenceCapableExcep tion: (Could not instantiate JDOTest.Person: Class org.apache.ojb.broker.util.ConstructorHelper can not access a member of class JDOTest.Person with modifiers "public") at org.apache.ojb.broker.util.ConstructorHelper.instantiate(Const ructorHelper.j ava:162) at org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl.buildWi thReflection(R owReaderDefaultImpl.java:235) ... 16 more Caused by: java.lang.IllegalAccessException: Class org.apache.ojb.broker.util.ConstructorHelper can not access a member of class JDOTest.Person with modifiers "public" at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:57) at java.lang.reflect.Constructor.newInstance(Constructor.java:268) at org.apache.ojb.broker.util.ConstructorHelper.instantiate(Const ructorHelper.j ava:158) ... 17 more org.apache.ojb.broker.PersistenceBrokerException: java.util.NoSuchElementException: Could not obtain next object: Unable to build object instance (MAYBE you don't have a constructor available):class JDOTest.Person at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:251) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:263) at org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollection ByQuery(Persis tenceBrokerImpl.java:997) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getColl ectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getColl ectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.jdori.sql.OjbExtent.<init>(OjbExtent.java:98) at org.apache.ojb.jdori.sql.OjbStoreManager.getExtent(OjbStoreMan ager.java:251) at com.sun.jdori.common.PersistenceManagerImpl.getExtent(Unknown Source) at com.sun.jdori.common.query.QueryImpl.checkCandidates(Unknown Source) at com.sun.jdori.common.query.QueryImpl.execute(Unknown Source) at JDOTest.TestJdo.run(TestJdo.java:52) at JDOTest.TestJdo.main(TestJdo.java:39) Caused by: java.util.NoSuchElementException: Could not obtain next object: Unable to build object instance (MAYBE you don't have a constructor available):class JDOTest.Person at org.apache.ojb.broker.accesslayer.RsIterator.next(RsIterator.java:310) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:147) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionB yQuery(QueryRe ferenceBroker.java:244) ... 11 more Exception in thread "main" javax.jdo.JDOUserException: Cannot close PersistenceManager while transaction is still active. at com.sun.jdori.common.PersistenceManagerImpl.close(Unknown Source) at com.sun.jdori.common.PersistenceManagerImpl.popCurrentWrapper(Unknown Source) at com.sun.jdori.common.PersistenceManagerWrapper.close(Unknown Source) at JDOTest.TestJdo.run(TestJdo.java:69) at JDOTest.TestJdo.main(TestJdo.java:39)
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