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Javax persistence persistenceexception

javax.persistence.PersistenceException: No Persistence prov > Ask Question

I am new to JPA & Hibernate. After reading some online materials I now understand what Hibernate is and how it can be used with JPA.

Now, I am trying to run this JPA & Hibernate tutorial. I’ve done everything they mention in this tutorial.

I don’t have Oracle DB, only MySQL. So I made some changes to persistence.xml using my understanding of JPA & Hibernate (I don’t know if it’s correct or not. Seems to me it is.)

Here is my persistence.xml

But I don’t seem to get the output they describe. It’s giving me:

Any suggestions will be appreciated.

Update:

I have made the changes that are asked to done. But, still getting the asme error lines.

They didnt mentioned anything about orm.xml in that tutorial. may it be a problem causer.

10 Answers 10

Your persistence.xml is not valid and the EntityManagerFactory can’t get created. It should be:

elements are closed, they shouldn’t be nested)

Update: I went through the tutorial and you will also have to change the Id generation strategy when using MySQL (as MySQL doesn’t support sequences). I suggest using the AUTO strategy (defaults to IDENTITY with MySQL). To do so, remove the SequenceGenerator annotation and change the code like this:

This should help.

PS: you should also provide a log4j.properties as suggested.

Just for completeness. There is another situation causing this error:

missing META-INF/services/javax.persistence.spi.PersistenceProvider file.

For Hibernate, it’s located in hibernate-entitymanager-XXX.jar , so, if hibernate-entitymanager-XXX.jar is not in your classpath, you will got this error too.

This error message is so misleading, and it costs me hours to get it correct.

I had the same problem today. My persistence.xml was in the wrong location. I had to put it in the following path:

I was facing the same issue. I realised that I was using the Wrong provider class in persistence.xml

For Hibernate it should be

And for EclipseLink it should be

If you use Hibernate 5.2.10.Final, you should change

in your persistence.xml

If you are using Maven you may have both src//resources/META-INF/persistence.xml . This is a common setup: test your JPA code with h2 or Derby and deploy it with PostgreSQL or some other full DBMS. If you’re using this pattern, do make sure the two files have different unit names, else some versions of the Persistence class will try to load BOTH (because of course your test-time CLASSPATH includes both classes and test-classes); this will cause conflicting definitions of the persistence unit, resulting in the dreaded annoying message that we all hate so much!

Worse: this may «work» with some older versions of e.g., Hibernate, but fail with current versions. Worth getting it right anyway.

A bit too late but I got the same issue and fixed it switching schemalocation into schemaLocation in the persistence.xml file (line 1).

I have seen this error , for me the issue was there was a space in the absolute path of the persistance.xml , removal of the same helped me.

I was also facing the same issue when I was trying to get JPA entity manager configured in Tomcat 8. First I has an issue with the SystemException class not being found and hence the entityManagerFactory was not being created. I removed the hibernate entity manager dependency and then my entityManagerFactory was not able to lookup for the persistence provider. After going thru a lot of research and time got to know that hibernate entity manager is must to lookup for some configuration. Then put back the entity manager jar and then added JTA Api as a dependency and it worked fine.

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my experience tells me that missing persistence.xml,will generate the same exception too.

i caught the same error msg today when i tried to run a jar package packed by ant.

when i used jar tvf to check the content of the jar file, i realized that «ant» forgot to pack the persistnece.xml for me.

after I manually repacked the jar file ,the error msg disappered.

Javax persistence persistenceexception

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javax-persistence-api / src / main / java / javax / persistence / PersistenceException.java

/*
* Copyright (c) 2008, 2009, 2011 Oracle, Inc. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution. The Eclipse Public License is available
* at http://www.eclipse.org/legal/epl-v10.html and the Eclipse Distribution License
* is available at http://www.eclipse.org/org/documents/edl-v10.php.
*/
package javax.persistence ;
/**
* Thrown by the persistence provider when a problem occurs.
* All instances of code >PersistenceException except for instances of
* < @link NoResultException>, < @link NonUniqueResultException>,
* < @link LockTimeoutException>, and < @link QueryTimeoutException>will cause
* the current transaction, if one is active, to be marked for rollback.
*
* @since Java Persistence 1.0
*/
public class PersistenceException extends RuntimeException <
/**
* Constructs a new code >PersistenceException exception
* with code >null as its detail message.
*/
public PersistenceException () <
super ();
>
/**
* Constructs a new code >PersistenceException exception
* with the specified detail message.
*
* @param message the detail message.
*/
public PersistenceException ( String message ) <
super (message);
>
/**
* Constructs a new code >PersistenceException exception
* with the specified detail message and cause.
*
* @param message the detail message.
* @param cause the cause.
*/
public PersistenceException ( String message , Throwable cause ) <
super (message, cause);
>
/**
* Constructs a new code >PersistenceException exception
* with the specified cause.
*
* @param cause the cause.
*/
public PersistenceException ( Throwable cause ) <
super (cause);
>
>
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Java Code Examples for javax.persistence.PersistenceException

The following code examples are extracted from open source projects. You can click to vote up the examples that are useful to you.

From project james-mailbox , under directory /jpa/src/main/java/org/apache/james/mailbox/jpa/ .

From project b3log-latke , under directory /latke/src/main/java/org/b3log/latke/repository/jpa/ .

From project Empire , under directory /core/src/com/clarkparsia/empire/impl/ .

From project OpenMEAP , under directory /server-side/openmeap-shared-serverside/src/com/openmeap/model/event/notifier/ .

From project seam-booking-ogm , under directory /src/main/java/org/jboss/seam/examples/booking/bootstrap/ .

From project ToHPluginUtils , under directory /src/main/java/org/tyrannyofheaven/bukkit/util/transaction/ .

From project hibernate-ogm , under directory /hibernate-ogm-core/src/main/java/org/hibernate/ogm/jpa/ .

From project james , under directory /data-jpa/src/main/java/org/apache/james/domainlist/jpa/ .

From project arquillian-showcase , under directory /spring/spring-jpa/src/main/java/com/acme/spring/jpa/repository/impl/ .

From project AuthDB , under directory /src/main/java/com/authdb/ .

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From project BabelCraft-Legacy , under directory /src/main/java/com/craftfire/babelcraft/ .

From project BanHammer , under directory /src/main/java/name/richardson/james/bukkit/banhammer/migration/ .

From project candlepin , under directory /src/main/java/org/candlepin/pinsetter/core/ .

From project cas , under directory /cas-server-core/src/main/java/org/jasig/cas/ticket/registry/support/ .

From project grails-data-mapping , under directory /grails-datastore-jpa/src/main/groovy/org/grails/datastore/mapping/jpa/ .

From project guice-jit-providers , under directory /extensions/persist/test/com/google/inject/persist/jpa/ .

From project jboss-jpa , under directory /impl/src/test/java/org/jboss/jpa/impl/test/beanvalidation/ .

From project JukeBukkit , under directory /src/main/java/cc/thedudeguy/jukebukkit/ .

From project ODE-X , under directory /runtime/src/main/java/org/apache/ode/runtime/exec/platform/ .

From project roborace , under directory /src/test/java/net/skhome/roborace/domain/repository/jpa/ .

From project ServiceFramework , under directory /src/net/csdn/jpa/context/ .

From project sisu-guice , under directory /extensions/persist/test/com/google/inject/persist/jpa/ .

From project SpringLS , under directory /src/main/java/com/springrts/springls/accounts/ .

From project TweakcraftUtils , under directory /src/com/guntherdw/bukkit/tweakcraft/ .

From project zanata , under directory /zanata-war/src/main/java/org/zanata/action/ .

From project zPermissions , under directory /src/main/java/org/tyrannyofheaven/bukkit/zPermissions/ .

JPA/Hibernate Persistence Context

Last modified: March 21, 2020

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1. Overview

Persistence providers like Hibernate make use of persistence context to manage the entity lifecycle in an application.

In this tutorial, we’ll start with the introduction of the persistence context, then we’ll see why it’s important. Finally, we’ll see the difference between transaction-scoped persistence context and extended-scoped persistence context with examples.

2. Persistence Context

Let’s take a look at the official definition of the Persistence Context:

An EntityManager instance is associated with a persistence context. A persistence context is a set of entity instances in which for any persistent entity identity there is a unique entity instance. Within the persistence context, the entity instances and their lifecycle are managed. The EntityManager API is used to create and remove persistent entity instances, to find entities by their primary key, and to query over entities.

The above statement may seem a bit complex right now, but it will make complete sense as we proceed. The persistence context is the first-level cache where all the entities are fetched from the database or saved to the database. It sits between our application and persistent storage.

Persistence context keeps track of any changes made into a managed entity. If anything changes during a transaction, then the entity is marked as dirty. When the transaction completes, these changes are flushed into persistent storage.

The EntityManager is the interface that lets us interact with the persistence context. Whenever we use the EntityManager, we are actually interacting with the persistence context.

If every change made in the entity makes a call to persistent storage, we can imagine how many calls will be made. This will lead to a performance impact because persistent storage calls are expensive.

3. Persistence Context Type

Persistence contexts are available in two types:

  • Transaction-scoped persistence context
  • Extended-scoped persistence context

Let’s take a look at each.

3.1 Transaction-Scoped Persistence Context

The transaction persistence context is bound to the transaction. As soon as the transaction finishes, the entities present in the persistence context will be flushed into persistent storage.

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When we perform any operation inside the transaction, the EntityManager checks for a persistence context. If one exists, then it will be used. Otherwise, it will create a persistence context.

The default persistence context type is PersistenceContextType.TRANSACTION. To tell the EntityManager to use the transaction persistence context, we simply annotate it with @PersistenceContext:

3.2 Extended-Scoped Persistence Context

An extended persistence context can span across multiple transactions. We can persist the entity without the transaction but cannot flush it without a transaction.

To tell EntityManager to use extended-scoped persistence context, we need to apply the type attribute of @PersistenceContext:

In the stateless session bean, the extended persistence context in one component is completely unaware of any persistence context of another component. This is true even if both are in same the same transaction.

Let’s say we persist some entity in a method of Component A, which is running in a transaction. We then call some method of Component B. In Component B’s method persistence context, we will not find the entity we persisted previously in the method of Component A.

4. Persistence Context Example

Now that we know enough about persistence context, it’s time to dive into an example. We’ll make different use cases with transaction persistence context and extended persistence context.

First, let’s create our service class, TransctionPersistenceContextUserService:

The next class, ExtendedPersistenceContextUserService, is very similar to the above, except for the @PersistenceContext annotation. This time we pass PersistenceContextType.EXTENDED into the type parameter of its @PersistenceContext annotation:

5. Test Cases

Now that we have our service classes set up, it’s time to make different use cases with transaction persistence context and extended persistence context.

5.1 Testing Transaction Persistence Context

Let’s persist a User entity using transaction-scoped persistence context. The entity will be saved in persistent storage. We then verify by making a find call using our extended persistence context’s EntityManager:

When we try to insert a User entity without a transaction, then TransactionRequiredException will be thrown:

5.2 Testing Extended Persistence Context

Next, let’s persist the user with an extended persistence context and without a transaction. The User entity will be saved in the persistence context (cache) but not in persistent storage:

In the persistence context for any persistent entity identity, there will be a unique entity instance. If we try to persist another entity with the same identifier:

We’ll see EntityExistsException:

Extended persistence context within a transaction saves the entity in persistent storage at the end of the transaction:

The extended persistence context flushes the cached entities into persistent storage when used within the transaction. First, we persist the entity without a transaction. Next, we persist another entity in the transaction:

6. Conclusion

In this tutorial, we gained a good understanding of the persistence context.

First, we looked at the transaction persistence context, which exists throughout the life of the transaction. Then, we looked at the extended persistence context, which can span across multiple transactions.

As always, the sample code is available over on GitHub.

Ссылка на основную публикацию
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