SOLVED: JDO - Unable to build object instance
()) {
System.out.println(No Product entries found!);
}
while (iter.hasNext()) {
House house = (House) iter.next();
System.out.println(house.toString());
}
manager.currentTransaction().commit();
} catch (Throwable t) {
t.printStackTrace();
}
finally {
manager.close();
}
}
private void getHouses() {
System.out.print(Insert house - ID: );
int house = Integer.parseInt(readLine());
System.out.println(All listings for house + house);
}
}
-Ursprüngliche Nachricht-
Von: Gus Heck [mailto:[EMAIL PROTECTED]
Gesendet: Sonntag, 21. Dezember 2003 17:17
An: OJB Users List
Betreff: Re: AW: AW: AW: JDO - Unable to build object instance
Sebastian,
One thing I notice that is different about your implementation (from
mine) is that your table name does not directly match your class name. I
think that _shouldn't_ matter, but it is a difference. There are few
other differences too.
I notice your jdo file is full of ojb-extensions to specify table names,
user name and such. This also differs from mine. Mine looks like this
(one class only shown, generated by Xdoclet)
?xml version=1.0 encoding=UTF-8?
!DOCTYPE jdo PUBLIC -//Sun Microsystems, Inc.//DTD Java Data Objects
Metadata 1.0//EN http://java.sun.com/dtd/jdo_1_0.dtd;
jdo
package name=org.cs101.fdb.impl.jdo
class name=LocationBase
identity-type=application
!-- end class tag --
/class
/package
!--
To use additional vendor extensions, create a vendor-extensions.xml
file that
contains the additional extensions (in extension tags) and place it
in your
projects merge dir.
--
/jdo
What is working for me is Xdoclet generated repository_user.xml, Xdoclet
generated package.jdo, and MySQL. Torque is creating the database tables
for me at runtime, though creating the tables at build time or
independantly should suffice so long as nothing silly happens like
creating tables in one db and then connecting to another. Insert usual
caveats about everything staying in sync here...
One direction you might take is to cut back to letting everything fall
into default naming and see if it works, then if it does, add in your
customizations one by one to see what breaks it.
Looking at your extension elements, I also just wondered this... did you
specify your user name and password in repository.xml
(repository_database.xml)? Granted the error message is very odd if that
is the type of problem here, but...
-Gus
Sebastian Muench wrote:
Hi,
at first, thank you for help so far. Unfortunately, the error message is
still appearing. I checked the information given by the doc you referred me
to, Gus. The strange thing at all is, that I can make new objects
persistent
without problems. But retrieving collections is still the problem. I
checked
and doublechecked everything, but don't know where's the problem.
My persistente class is House. I'm testing on the HSQLDB, comming with OJB.
I prepare my user class for enhancing by compiling it as usual, and copy
the
class files to my dir target/classes/package/ and
target/classestest/package/
As I already wrote, enhancing is successful.
Here some important lines from my repository_jdo.xml, House.jdo,
House.java,
etc.
SQL statement for the table in HSQLDB
CREATE TABLE Seb_House (
ID INTEGER NOT NULL PRIMARY KEY,
NAME VARCHAR)
Corresponding mapping tags in repository_jdo.xml
!-- Definitions for dbsii.House --
class-descriptor
class=dbsii.House
table=Seb_House
field-descriptor
name=id
column=ID
jdbc-type=INTEGER
primarykey=true
/
field-descriptor
name=name
column=NAME
jdbc-type=VARCHAR
/
/class-descriptor
The persistente class file
package dbsii;
import java.io.Serializable;
class House implements Serializable {
private int id;
protected String name;
public House() {
}
public House(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;
}
public String toString() {
return [ + this.id + ] + this.name;
}
}
The corresponding House.jdo
?xml version=1.0 encoding=UTF-8?
!DOCTYPE jdo PUBLIC -//Sun Microsystems, Inc.//DTD Java Data Objects
Metadata 1.0//EN http://java.sun.com/dtd/jdo_1_0.dtd;
jdo
!--extension vendor-name=ojb key=dbplatform value=hsqldb/
extension vendor
AW: AW: JDO - Unable to build object instance
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.
-Ursprüngliche 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
Person.class
package JDOTest;
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();
}
}
}
-Ursprüngliche 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,
Does your class have a public default constructor?
From _Core Java Data Objects_ page 51:
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
AW: JDO - Unable to build object instance
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
Person.class
package JDOTest;
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();
}
}
}
-Ursprüngliche 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,
Does your class have a public default constructor?
From _Core Java Data Objects_ page 51:
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
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.buildWithReflection(R owReaderDefaultImpl.java:239) at org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl.readObjectFrom(RowRea derDefaultImpl.java:115) at org.apache.ojb.broker.accesslayer.RsIterator.getObjectFromResultSet(RsIterat or.java:463) at org.apache.ojb.broker.accesslayer.RsIterator.next(RsIterator.java:284) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery(QueryRe ferenceBroker.java:147) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery(QueryRe ferenceBroker.java:244) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery(QueryRe ferenceBroker.java:263) at org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollectionByQuery(Persis tenceBrokerImpl.java:997) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getCollectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getCollectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.jdori.sql.OjbExtent.init(OjbExtent.java:98) at org.apache.ojb.jdori.sql.OjbStoreManager.getExtent(OjbStoreManager.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.ClassNotPersistenceCapableException: (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(ConstructorHelper.j ava:162) at org.apache.ojb.broker.accesslayer.RowReaderDefaultImpl.buildWithReflection(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(ConstructorHelper.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.getCollectionByQuery(QueryRe ferenceBroker.java:251) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery(QueryRe ferenceBroker.java:263) at org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollectionByQuery(Persis tenceBrokerImpl.java:997) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getCollectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.broker.core.DelegatingPersistenceBroker.getCollectionByQuery( DelegatingPersistenceBroker.java:322) at org.apache.ojb.jdori.sql.OjbExtent.init(OjbExtent.java:98) at org.apache.ojb.jdori.sql.OjbStoreManager.getExtent(OjbStoreManager.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.getCollectionByQuery(QueryRe ferenceBroker.java:147) at org.apache.ojb.broker.core.QueryReferenceBroker.getCollectionByQuery(QueryRe ferenceBroker.java:244) ... 11 more Exception in thread main javax.jdo.JDOUserException: Cannot
JDO Enhancer
Hi, I get an error class given to extent does not implement javax.jod.spi.PersistenteCapable anytime I run my jdo-application. I put the mapping entries in the repository_jdo.xml. I don't know how to set up the bytecode enhancer. Do I have to compile my SourceCode a second time including the enhancer? How do I have to do that? Thanks for any kind of help (including hints where to find documentation) Greetinx, Sebastian - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
install jdo-api
Hi all, I try to execute the jdo-tutorial after installing ojb by following the quickstart guide. I added the obj/lib directory to my classpath. The tutorial applicaions 1 and 2 are running fine. By building the jdo-tutorial (using bin/build.sh with-jdori prepare-tutorials enhance-jdori ), I get the following error (please see below). Does anybody know how to fix that? Thanx for help, Sebastian [EMAIL PROTECTED] db-ojb-1.0.rc4]# bin/build.sh with-jdori prepare-tutorials enhance-jdori Buildfile: build.xml splash: set-archive-name: set-archive-name-date: detect-jdk: check-jdk12proxy-classes: check-jndi-classes: use-jdk12: use-jdk13: use-jdk14: [echo] detected JDK 1.4 init: prepare: check-jdo-classes: check-jdori-classes: with-jdori: [copy] Copying 16 files to /usr/local/src/db-ojb-1.0.rc4/target/src [copy] Copying 1 file to /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/tutorial5 splash: set-archive-name: set-archive-name-date: detect-jdk: check-jdk12proxy-classes: check-jndi-classes: use-jdk12: use-jdk13: use-jdk14: [echo] detected JDK 1.4 init: prepare: check-j2ee-classes: preprocess: [echo] using switches: +JDK13, +JDBC30 [java] [java] ... main: [javac] Compiling 564 source files to /usr/local/src/db-ojb-1.0.rc4/target/classes [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbStoreMa nager.java:76: cannot resolve symbol [javac] symbol : class RuntimeJDOModelFactoryImpl [javac] location: package jdo [javac] import com.sun.jdori.common.model.jdo.RuntimeJDOModelFactoryImpl; [javac] ^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbStoreMa nager.java:80: cannot resolve symbol [javac] symbol : class JDOModelException [javac] location: package jdo [javac] import com.sun.jdori.model.jdo.JDOModelException; [javac]^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbFieldMa nager.java:64: cannot resolve symbol [javac] symbol : class RuntimeJDOModelFactoryImpl [javac] location: package jdo [javac] import com.sun.jdori.common.model.jdo.RuntimeJDOModelFactoryImpl; [javac] ^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbFieldMa nager.java:68: cannot resolve symbol [javac] symbol : class JDOModelException [javac] location: package jdo [javac] import com.sun.jdori.model.jdo.JDOModelException; [javac]^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbStoreMa nager.java:252: cannot resolve symbol [javac] symbol : variable RuntimeJDOModelFactoryImpl [javac] location: class org.apache.ojb.jdori.sql.OjbStoreManager [javac] JDOModel m = RuntimeJDOModelFactoryImpl.getInstance().getJDOModel(cl); [javac] ^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbStoreMa nager.java:255: cannot resolve symbol [javac] symbol : class JDOModelException [javac] location: class org.apache.ojb.jdori.sql.OjbStoreManager [javac] catch (JDOModelException ex) [javac]^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbFieldMa nager.java:289: cannot resolve symbol [javac] symbol : variable RuntimeJDOModelFactoryImpl [javac] location: class org.apache.ojb.jdori.sql.OjbFieldManager [javac] JDOModel m = RuntimeJDOModelFactoryImpl.getInstance().getJDOModel(cl); [javac] ^ [javac] /usr/local/src/db-ojb-1.0.rc4/target/src/org/apache/ojb/jdori/sql/OjbFieldMa nager.java:292: cannot resolve symbol [javac] symbol : class JDOModelException [javac] location: class org.apache.ojb.jdori.sql.OjbFieldManager [javac] catch (JDOModelException ex) [javac]^ [javac] 8 errors BUILD FAILED file:/usr/local/src/db-ojb-1.0.rc4/build.xml:218: Compile failed; see the
