hibernate hello world

hi ranchers,

i am creating a java project in eclipse using the hibernate 3.0


i do not know where to put the mapping configuration file (applabsuser.hbm.xml)
and
hibernate configuration file (hibernate.cfg.xml)



i have my POJO class in src\org.applabs.quickstart\AppLabsUser.java

Hi naveen,

you can have your all mapping configuration file in same project but in different package.

But you've to configure the mapping correctly.

For eg, you moving hbm file in src\org.applabs.quickstart.hbm\applabsuser.hbm.xml

you've to configure mapping in hibernate.cfg.xml as follows

<mapping resource="org\applabs\quickstart\hbm\applabsuser.hbm.xml " />


you can put hibernate.cfg.xml file where ever you want. But while reading this file for creating session factory, you should give exact file location.




Thanks.

there is how i palce various file in Hibernate 3 hello application


mapping file in src\org.applabs.quickstart\hbm\applabsuser.hbm.xml



and

hibernate cong file in \src\hibernate.cfg.xml





here is my main class



and on running above file i am getting
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:39)
Resource: applabsuser.hbm.xml not found


it seems that session object has not been instantiated. but why ?

Please note that i have included only hibernate3.jar in build-path Do i have to add other jar files ?

Hi,

Have you created session factory for your database connection?

here it is

hibernate.cfg.xml


and

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
problem parsing configuration/hibernate.cfg.xml
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:35)


what is problem in above xml file ?

Madhavi Subramaniam wrote:Hi,

Have you created session factory for your database connection?

how do i do that ?

Hi,

Have you added sqljdbc.jar in your build path?

i have added mysql-connector-java-5.1.6-bin.jar in build-path

and i have added all jar files which comes with hibernate3 distribution.

Post the full exception stack trace. It should have the details on what is wrong in the XML file.

Hi,

I think,your connnection url value in wrong format.

If your DB name is university,It should be like

<property name="hibernate.connection.url">jdbc:sqlserver://localhost:3306;databaseName=university</property>

3306 is your sql server running port number rite?

here is hibernate.cfg.xml




irrespective of <property name="hibernate.connection.url">jdbc:sqlserver://localhost:3306;databaseName=university</property> still throws exception

and full stack trace of exception.

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
org.hibernate.HibernateException: problem parsing configuration/hibernate.cfg.xml
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1222)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1161)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1147)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:18)
Caused by: org.dom4j.DocumentException: Error on line 2 of document : The processing instruction target matching "[xX][mM][lL]" is not allowed. Nested [/b]exception: The processing instruction target matching "[xX][mM][lL]" is not allowed.
at org.dom4j.io.SAXReader.read(SAXReader.java:350)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1217)
... 3 more
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:38)

This means there are some white spaces before the XML declaration..

Madhavi Subramaniam wrote:Hi,

I think,your connnection url value in wrong format.

If your DB name is university,It should be like

<property name="hibernate.connection.url">jdbc:sqlserver://localhost:3306;databaseName=university</property>

URL is in correct format, it should work with what the OP is having.

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
org.hibernate.MappingException: Error reading resource: org/applabs/quickstart/applabsuser.hbm.xml
at org.hibernate.cfg.Configuration.addResource(Configuration.java:448)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1312)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1284)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1266)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1233)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1161)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1147)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:15)
Caused by: org.hibernate.MappingException: class org.applabs.hibernate.quickstart.AppLabsUser not found while looking for property: userName
at org.hibernate.util.ReflectHelper.reflectedPropertyClass(ReflectHelper.java:81)
at org.hibernate.mapping.SimpleValue.setTypeUsingReflection(SimpleValue.java:254)
at org.hibernate.cfg.HbmBinder.createProperty(HbmBinder.java:1753)
at org.hibernate.cfg.HbmBinder.createClassProperties(HbmBinder.java:1742)
at org.hibernate.cfg.HbmBinder.bindRootPersistentClassCommonValues(HbmBinder.java:317)
at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinder.java:235)
at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:151)
at org.hibernate.cfg.Configuration.add(Configuration.java:359)
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:396)
at org.hibernate.cfg.Configuration.addResource(Configuration.java:445)
... 7 more
Caused by: java.lang.ClassNotFoundException: org.applabs.hibernate.quickstart.AppLabsUser
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:108)
at org.hibernate.util.ReflectHelper.reflectedPropertyClass(ReflectHelper.java:77)
... 16 more
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:32)


i have AppLabsUser.java in org.applabs.quickstart but there is not a AppLabsUser.class file.why it is not been created ?

naveen yadav wrote:
Caused by: java.lang.ClassNotFoundException: org.applabs.hibernate.quickstart.AppLabsUser

This is the root cause. It cannot find the specified class.
Post your hbm file and the AppLabsUser.java file.

applabsuser.hbm.xml in org.applabs.quickstart




and here is AppLabsUser.java in org.applabs.quickstart

in applabsuser.hbm.xml

replace
<hibernate-mapping>
<class name="org.applabs.hibernate.quickstart.AppLabsUser" table="applabsuser">

with
<hibernate-mapping>
<class name="org.applabs.quickstart.AppLabsUser" table="applabsuser">

and now

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
org.hibernate.MappingException: could not instantiate id generator
at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:94)
at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:135)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:166)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1054)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:15)
Caused by: org.hibernate.MappingException: Dialect does not support sequences
at org.hibernate.dialect.Dialect.getSequenceNextValString(Dialect.java:413)
at org.hibernate.id.SequenceGenerator.configure(SequenceGenerator.java:65)
at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:90)
... 4 more
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:32)

naveen yadav wrote:
and here is AppLabsUser.java in org.applabs.quickstart

But, what you give in hbm file, is org.applabs.hibernate.quickstart.AppLabsUser.
Change it to org.applabs.quickstart.AppLabsUser.

now after change applabsuser.hbm.xml


and now

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
org.hibernate.MappingException: could not instantiate id generator
at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:94)
at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:135)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:166)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1054)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:15)
Caused by: org.hibernate.MappingException: Dialect does not support sequences
at org.hibernate.dialect.Dialect.getSequenceNextValString(Dialect.java:413)
at org.hibernate.id.SequenceGenerator.configure(SequenceGenerator.java:65)
at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:90)
... 4 more
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:32)

It tells, the database does not support sequences. You can try with generator class="increment" to have it incremented automatically or "assigned" to assign the value yourself.

once again i have changed applabsuser.hbm.xml




Caused by: java.sql.SQLException: No suitable driver found for jdbc:sqlserver://localhost:3306;databaseName=university
at java.sql.DriverManager.getConnection(DriverManager.java:602)
at java.sql.DriverManager.getConnection(DriverManager.java:154)
at org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:110)
at org.hibernate.jdbc.AbstractBatcher.openConnection(AbstractBatcher.java:410)
... 7 more


but i have another simple application using same database is running fine

naveen yadav wrote:
Caused by: java.sql.SQLException: No suitable driver found for jdbc:sqlserver://localhost:3306;databaseName=university

Change the driver to one, you had earlier in hibernate.cfg.xml.

after doing chnges


log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
org.hibernate.PropertyNotFoundException: Could not find a getter for id in class org.applabs.quickstart.AppLabsUser
at org.hibernate.property.BasicPropertyAccessor.createGetter(BasicPropertyAccessor.java:213)
at org.hibernate.property.BasicPropertyAccessor.getGetter(BasicPropertyAccessor.java:207)
at org.hibernate.tuple.PropertyFactory.getGetter(PropertyFactory.java:148)
at org.hibernate.tuple.PropertyFactory.buildIdentifierProperty(PropertyFactory.java:41)
at org.hibernate.tuple.EntityMetamodel.<init>(EntityMetamodel.java:105)
at org.hibernate.persister.entity.BasicEntityPersister.<init>(BasicEntityPersister.java:400)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:104)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:199)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1054)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:15)
Exception in thread "main" java.lang.NullPointerException
at org.applabs.quickstart.FirstExample.main(FirstExample.java:34)


in AppLabsUser.java

[code=java
int id;
public int getUserId() {
return this.id;
}

public void setUserId(int id) {
this.id = id;
}[/code]


in university database
id is represented by USER_ID --type is int

and here is how i insert user id from FirstExample.java(main class)

int ii=88;
user.setUserId(ii);

You need to have setters/getters in the standard format. My suggestion is use your IDE, to generate them.

i have creted setter and getter method using IDE.

applabsuser table in database




main class



log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Hibernate: update applabsuser set USER_NAME=?, USER_PASSWORD=?, USER_FIRST_NAME=?, USER_LAST_NAME=?, USER_EMAIL=? where USER_ID=?
org.hibernate.StaleStateException: Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1
at org.hibernate.jdbc.BatchingBatcher.checkRowCount(BatchingBatcher.java:88)
at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:74)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:57)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:172)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:226)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:137)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:274)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:675)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:293)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:86)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:28)


org.hibernate.StaleStateException
Thrown when a version number or timestamp check failed, indicating that the Session contained stale data (when using long transactions with versioning).

Ideally, it should have been insert query, don't know, why its become update query. Can you check by making it session.save(user) instead of session.saveOrUpdate(user)

Prasad Krishnegowda wrote: Can you check by making it session.save(user) instead of session.saveOrUpdate(user)

with that it is like


log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Hibernate: insert into applabsuser (USER_NAME, USER_PASSWORD, USER_FIRST_NAME, USER_LAST_NAME, USER_EMAIL) values (?, ?, ?, ?, ?)
org.hibernate.exception.GenericJDBCException: could not insert: [org.applabs.quickstart.AppLabsUser]
at org.hibernate.exception.ErrorCodeConverter.handledNonSpecificException(ErrorCodeConverter.java:92)
at org.hibernate.exception.ErrorCodeConverter.convert(ErrorCodeConverter.java:80)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.persister.entity.BasicEntityPersister.insert(BasicEntityPersister.java:1790)
at org.hibernate.persister.entity.BasicEntityPersister.insert(BasicEntityPersister.java:2192)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:34)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:239)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:238)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:158)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:104)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:184)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:173)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:69)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:429)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:424)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:29)
Caused by: java.sql.SQLException: Field 'USER_ID' doesn't have a default value
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2019)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1937)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1922)
at org.hibernate.persister.entity.BasicEntityPersister.insert(BasicEntityPersister.java:1772)
... 14 more
Exception in thread "main" org.hibernate.AssertionFailure: null id in entry (don't flush the Session after an exception occurs)
at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:49)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:82)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:190)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:70)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:26)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:675)
at org.applabs.quickstart.FirstExample.main(FirstExample.java:37)

have you mapped user_id column, how is the value set to this field?

userId is a primary key in a table


USER_ID does not have default value since it is a primary key
i could not understand why there is Caused by: java.sql.SQLException: Field 'USER_ID' doesn't have a default value .Should i assign default value to it.

this is how i mapped user_id in applasuser.hbm.xml




and in FirstExample.java(main) trying to set a user_id.

Hibernate: insert into applabsuser (USER_NAME, USER_PASSWORD, USER_FIRST_NAME, USER_LAST_NAME, USER_EMAIL) values (?, ?, ?, ?, ?)

This statement doesn't show the userid, it means there is some mistake in mapping the column of the table.

USER_ID is a primary key and have been mapped to POJP property userId in applabsuser.xml

can you change that class from native to assigned.. in the java code, you are assigning that. Native means, the underlying database only decides its value.

Prasad Krishnegowda wrote:can you change that class from native to assigned.. in the java code, you are assigning that. Native means, the underlying database only decides its value.

after doing suggested changes.



Now there is a new row is inserted into the a database table.finally Hibernate Hello World is working.


Thank you very much Prasad Krishnegowda. I appreciates your effort. you help it right through the code. You kindly help at every single error
thanks.

Great.. Nice to hear, you finally made it work..
Welcome brother