I'm working on an web application using Hibernate 4, Spring 3. I'm struggling with an issue for days.
In the application I have an entity class named 'User':
#Entity
public class User {
#Id
private int uid;
#Column(unique = true)
private String username;
private String password;
private boolean confirmed;
//... getters and setters
}
This entity class is mapped from a table of db called 'user'.
There is another entity class named 'Confirmation':
#Entity
#NamedQueries({
#NamedQuery(name = "getAllConfirmations", query = "select c from Confirmation c")
})
public class Confirmation {
#Id
private String username;
private boolean confirmed;
//... getters and setters
}
This entity class is mapped from a view of db called 'confirmation'.
create view confirmation
as
select username,confirmed from user
I have a method in my service class to get list of all Confirmation object:
public List<Confirmation> getListOfConfirmations() {
Query query = entityManager.createNamedQuery("getAllConfirmations");
return query.getResultList();
}
Also, there's a method to confirm User objects- set confirmed field 'true':
public int confirmUser(int uid) {
User user = getUser(uid);
if (user != null) {
user.setConfirmed(true);
try {
entityManager.getTransaction().begin();
entityManager.merge(user);
entityManager.getTransaction().commit();
return 1;
} catch (Exception e) {
e.printStackTrace();
}
}
return 0;
}
When I call confirmUser() it works fine and User object and it's row in database would be changed, But when I call getListOfConfirmations() after changes no change would be viewed in the result list.
It seems, by default, hibernate caches query result of views.
Is there any way to prevent hibernate to prevent caches this result.
In addition, I've tried #Cacheable(false) for Confirmation class or set #QueryHint(name = "org.hibernate.cacheable", value = "false") for getAllConfirmations named query, these don't work.
Persistence config:
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<persistence-unit name="MyPU" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<class>bob.jpacache.Confirmation</class>
<class>bob.jpacache.User</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
<property name="hibernate.connection.url" value="jdbc:mysql://localhost/cachetest"/>
<property name="hibernate.connection.username" value="root"/>
<property name="hibernate.connection.password" value="root"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
<property name="hibernate.show_sql" value="true"/>
<property name="hibernate.format_sql" value="true"/>
</properties>
</persistence-unit>
</persistence>
Thanks, in advance, for your help.
#Cacheable refers to the second-level cache and your problem seems to me that it is in the first level cache. I believe that the problem is in the life cycle of your EntityManager (at what time you create a new, at what time you close it), do a simple test: after the change of the User's objects, try call entityManager.clear () and then query your Confirmation object. NOTE: entityManager.clear () must be called on the same EntityManager that will be used to make the query.
Another detail, do not know what his real purpose, but the query has no filter. Thus, whether the User has to confirm or not, will always bring all records of User table.
Related
i want to query a mongodb here my code
Persistence.xml
<?xml version="1.0"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="primary" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ogm.jpa.HibernateOgmPersistence</provider>
<properties>
<property name="hibernate.transaction.jta.platform" value="org.hibernate.service.jta.platform.internal.JBossStandAloneJtaPlatform"/>
<property name="hibernate.ogm.datastore.provider" value="mongodb" />
<property name="hibernate.ogm.datastore.database" value="******" />
<property name="hibernate.ogm.datastore.host" value="******" />
<property name="hibernate.ogm.datastore.port" value="******" />
<property name="hibernate.ogm.datastore.username" value="******" />
<property name="hibernate.ogm.datastore.password" value="******" />
</properties>
</persistence-unit>
</persistence>
Flux.java
#Entity
#Table(catalog="f12", schema="public", name="enl_flux_f12_entry")
public class enl_flux_f12_entry{
#Id
public String id;
public String SYS_FluxName;
public byte[] SYS_ReadDateTime;
public String SYS_BaseNameZip;
public Long SYS_Status;
public String SYS_DateCreaERDF;
}
main
public static void main(String[] args) throws ClassNotFoundException{
EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory( "primary" );
EntityManager entityManager = entityManagerFactory.createEntityManager();
entityManager.getTransaction().begin();
enl_flux_f12_entry f = entityManager.find(Flux.class, "*id*");
System.out.println(f.id);
entityManager.flush();
entityManager.close();
}
mongodb
{
"_id" : ObjectId("rzerzer"),
"SYS_FluxName" : "zerzerze.xml",
"SYS_ReadDateTime" : Timestamp(6300883749567463, 83),
"SYS_BaseNameZip" : "rferfer.zip",
"SYS_Status" : NumberLong(1),
"SYS_DateCreaERDF" : "2016-03-01T20:38:48Z"
}
The problem is that entityManager.find return always null. Is there any problem in my code?
I think it returns null because something odd in the mapping or in the JSON object and it cannot find the entity you are looking for.
The JSON object you want to get has _id: ObjectId("rzerzer"), this doesn't look right because an ObjectId in MongoDB should be:
The 12-byte ObjectId value consists of:
a 4-byte value representing the seconds since the Unix epoch,
a 3-byte machine identifier,
a 2-byte process id, and
a 3-byte counter, starting with a random value.
Even if the object in the DB is right, it is mapped as a String, so Hibernate OGM does not expect an ObjectId.
The mapping of the id on the entity should be:
#Id
#Type(type = "objectid")
public String id;
or
#Id
public ObjectId id;
Another strange thing is the way you are using find:
enl_flux_f12_entry f = entityManager.find(Flux.class, "*id*");
the find method requires the exact id of the entity. If the mapping is right, this should work entityManager.find(Flux.class, "rzerzer");
If you are not sure about the id value in the db you can also use HQL:
List<Flux> entries = entityManager.createQuery( "from Flux" ).list();
i'm trying to make a simple multitenant example to run, using Eclipselink 2.5.2, and MySQL.
When trying to persist an entity asigned to a tenant id, mysql server throws an error: "Table 'jpatest.tenant1_userdata' doesn't exist". (userdata being the entity, jpatest the database name, and tenant1 the tenant-id)
The table indeed doesn't exist, the database jpatest do exist. I was expecting eclipselink to autogenerate the tables each time i try to persist with a new tenant id.
So the question would be:
How can i force Eclipselink to create the tables?
If that is not possible; How can i create tables at runtime?
Here's the code:
Entity:
#Entity
#Table(name = "userdata")
#Multitenant(value = MultitenantType.TABLE_PER_TENANT)
#TenantTableDiscriminator(type = TenantTableDiscriminatorType.PREFIX, contextProperty = "tenant-id")
public class UserData implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
private static final long serialVersionUID = 1L;
private String name;
.
.
.
persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="MultiTeanantTest" transaction-type="RESOURCE_LOCAL">
<class>UserData</class>
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/jpatest" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password" value="" />
<property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
<property name="javax.persistence.schema-generation.create-database-schemas" value="true"/>
<property name="eclipselink.ddl-generation" value="create-tables"/>
</properties>
</persistence-unit>
</persistence>
Main class:
public class Main {
public static void main(String[] args) {
UserData ud = new UserData();
ud.setNombre("John);
Map properties = new HashMap<>();
properties.put("tenant-id", "tenant1");
EntityManagerFactory emf = Persistence.createEntityManagerFactory("MultiTeanantTest", properties );
EntityManager em = emf.createEntityManager();
em.getTransaction().begin();
em.persist(ud);
em.getTransaction().commit();
}
}
Hope someone can give me a tip in what i'm doing wrong.
DDL generation will not be supported in a Multitenant Scenario by Eclipselink.
Refer to this link for more information, https://wiki.eclipse.org/EclipseLink/DesignDocs/Multi-Tenancy/TablePerTenant
I'm using datanucleus 3.2.7 from Maven, trying to use the Amazon S3 JPA provider. I can successfully write data into S3, but querying either by using "SELECT u FROM User u" or "SELECT u FROM User u WHERE id = :id" causes a NullPointerException to be thrown when I call query.getResultList().
Using the RDBMS provider, everything works perfectly. Is there something I'm doing wrong?
Main.java
EntityManagerFactory factory = Persistence.createEntityManagerFactory("MyUnit");
EntityManager entityManager = factory.createEntityManager();
Query query = entityManager.createQuery("SELECT u FROM User u", User.class);
List<User> users = query.getResultList(); // Null pointer exception here (This is line 16!)
for(User u:users)
System.out.println(u);
User.java
package test;
import javax.persistence.*;
#Entity
#Table(name = "User")
public class User {
#Id
public String id;
public String name;
public User(String id, String name) {
this.id = id;
this.name = name;
}
public String toString() {
return id+" : "+name;
}
}
persistence.xml
<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
version="1.0">
<persistence-unit name="MyUnit">
<class>test.User</class>
<exclude-unlisted-classes />
<properties>
<properties>
<property name="datanucleus.ConnectionURL" value="amazons3:http://s3.amazonaws.com/" />
<property name="datanucleus.ConnectionUserName" value="xxxxx" />
<property name="datanucleus.ConnectionPassword" value="xxxxx" />
<property name="datanucleus.cloud.storage.bucket" value="my-bucket" />
</properties>
<property name="datanucleus.autoCreateSchema" value="true" />
</properties>
</persistence-unit>
</persistence>
Exception
java.lang.NullPointerException
at org.datanucleus.NucleusContext.isClassWithIdentityCacheable(NucleusContext.java:1840)
at org.datanucleus.ExecutionContextImpl.getObjectFromLevel2Cache(ExecutionContextImpl.java:5287)
at org.datanucleus.ExecutionContextImpl.getObjectFromCache(ExecutionContextImpl.java:5191)
at org.datanucleus.ExecutionContextImpl.findObject(ExecutionContextImpl.java:3137)
at org.datanucleus.store.json.CloudStoragePersistenceHandler.getObjectsOfCandidateType(CloudStoragePersistenceHandler.java:367)
at org.datanucleus.store.json.query.JPQLQuery.performExecute(JPQLQuery.java:94)
at org.datanucleus.store.query.Query.executeQuery(Query.java:1786)
at org.datanucleus.store.query.Query.executeWithMap(Query.java:1690)
at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:194)
at test.Main.main(Main.java:16)
This error appears to be happening as datanucleus deserializes the JSON for an entry. Deleting everything from the bucket returns the empty set without incident. By turning off L2 Caching, I made the exception occur somewhere else. It seems that ExecutionContextImpl.findObject is being given a null id.
datanucleus-json version 3.2.1 likely fixes that, but that's for you to confirm
Ok this is a weird problem because I had it working before.
So I have 2 classes: game and developer. They have a many to many relationship.
The persistency unit makes automatically the table game_developer.
Thus there are 3 tables: game developer and game_developer.
When I enter Information inside the database. The table game and developer will get there values as normal but the table game_developer will remain empty. So the relationship isn't recognized.
Also when I run the webapp everything inside the tables should be dropped. The developer drops fine but the game remains to exist.
Any push in the right direction is appreciated.
Thank you in advance,
David
Initialization:
try {
gameOrganizer = (GameOrganizer) getServletContext().getAttribute("database");
Game game = new Game("Counter Strike: source");
Game game2 = new Game("Battlefield: bad company 3");
Game game3 = new Game("Killing floor");
Developer devel = new Developer("valve");
Developer devel2 = new Developer("EA Games");
Developer devel2b = new Developer("DICE");
Developer devel3 = new Developer("Ubisoft");
//The GameOrganizer is the controller between the model en the view.
//The view being the website.
//So gameOrganizer.addGame(game) will persist the object to the database.
gameOrganizer.addGame(game);
gameOrganizer.addGame(game2);
gameOrganizer.addGame(game3);
gameOrganizer.addDeveloper(devel);
gameOrganizer.addDeveloper(devel2);
gameOrganizer.addDeveloper(devel2b);
gameOrganizer.addDeveloper(devel3);
game.addDeveloper(devel);
devel.getGames().add(game);
game2.addDeveloper(devel2);
devel2.getGames().add(game2);
game2.addDeveloper(devel2b);
devel2b.getGames().add(game2);
game3.addDeveloper(devel3);
devel3.getGames().add(game3);
} catch (DatabaseException ex) {
Logger.getLogger(GameController.class.getName()).log(Level.SEVERE, null, ex);
} catch (DomainException ex) {
Logger.getLogger(GameController.class.getName()).log(Level.SEVERE, null, ex);
}
The game class:
#Entity
public class Game implements Serializable{
private String gameNaam;
private double prijs;
#ManyToMany(mappedBy = "games")
private Collection<Developer> developers = new ArrayList<Developer>();
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
public Game(){};
.
.
//methods
.
.
}
The Developer class
#Entity
public class Developer implements Serializable {
private String naam;
private String info;
#ManyToMany
private Collection<Game> games = new ArrayList<Game>();
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
public Developer() {
}
.
.
//methods
.
.
}
The persistency Unit:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="GameDatabaseSitePU" transaction-type="RESOURCE_LOCAL">
<provider>oracle.toplink.essentials.PersistenceProvider</provider>
<class>domainmodel.Developer</class>
<class>domainmodel.Game</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="toplink.jdbc.user" value="app"/>
<property name="toplink.jdbc.password" value="app"/>
<property name="toplink.jdbc.url" value="jdbc:derby://localhost:1527/GameDatabase;create=true"/>
<property name="toplink.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
<property name="toplink.ddl-generation" value="drop-and-create-tables"/>
</properties>
</persistence-unit>
</persistence>
The relationship isn't recognized because you persist the objects before you establish the relationships. Do the calls gameOrganizer.add..() after you add the objects to each others collections. Also add persist on cascade to your many-to-many relationship of developers:
#ManyToMany(cascade = CascadeType.PERSIST, mappedBy = "games")
private Collection<Developer> developers = new ArrayList<Developer>();
Then you only need to persist the games.
I think in a bi-directional many-to-many relationship you need to set both sides ...
i.e. if you do
devel.getGames().add(game);
you also need to do
game.getDeveloper().add(devel);
otherwise JPA will not really see the other side, the insert into the mapping table will be something like (FK1, null), which will fail, which is why you won't see any entry ...
I don't know much about toplink, but i think something like
<property name="toplink.logging.level" value="FINE"/>
should give you sql statements in your logging which help a lot debugging these kind of problems :)
I'm having trouble handling IDs of my databse tables using OpenJPA and HSQLdb. I created an Abstract class where I handle annotations and stuff to remap into the DB:
// Property accessors
#Id
#Column(name = "IDTESTOBJEKT", unique = true, nullable = false)
public Integer getIdtestobjekt() {
return this.idtestobjekt;
}
public void setIdtestobjekt(Integer idtestobjekt) {
this.idtestobjekt = idtestobjekt;
}
It's as a Facade used to create Testobjekts.
Testobjekt test_obj = new Testobjekt();
test_obj.setEigentuemerin("helge");
// test_obj.setIdtestobjekt(1);
EntityManagerHelper.beginTransaction();
TestobjektDAO test_dao = new TestobjektDAO();
test_dao.save(test_obj);
EntityManagerHelper.commit();
List<Testobjekt> foo;
foo = test_dao.findByEigentuemerin("helge");
Testobjekt from_db = foo.get(0);
System.out.println(from_db.getEigentuemerin());
Nevertheless what I set ... 1, nothing... I get errors.
Like:
Field "model_layer.AbstractTestobjekt.idtestobjekt" of "model_layer.Testobjekt#3209fa8f" can not be set to "null" value.
I want the ORM layer to handle that ID stuff without bothering me. My experience with Hibernate is that is handles that stuff quite well... but OpenJPA seems to be cumbersome here. I assume my annotations are wrong or something but I'm having trouble tracking this multi-layered issue down.
I configured OpenJPA in the persistence.xml:
<persistence-unit name="HSQLdb_mvn_openJPA_autoTablesPU"
transaction-type="RESOURCE_LOCAL">
<provider>
org.apache.openjpa.persistence.PersistenceProviderImpl
</provider>
<class>model_layer.Testobjekt</class>
<class>model_layer.AbstractTestobjekt</class>
<properties>
<property name="openjpa.ConnectionDriverName"
value="org.hsqldb.jdbc.JDBCDriver" />
<property name="openjpa.ConnectionURL"
value="jdbc:hsqldb:hsql://localhost:9001/mydb" />
<property name="openjpa.ConnectionUserName" value="SA" />
<property name="openjpa.jdbc.SynchronizeMappings"
value="buildSchema(ForeignKeys=true)" />
</properties>
</persistence-unit>
How do I handle an automated ID strategy with OpenJPA?
Thanks,
wishi
How do I handle an automated ID strategy with OpenJPA?
Use the #GeneratedValue annotation (and I suggest using the default GenerationType.AUTO strategy which indicates that the persistence provider should pick an appropriate strategy for the particular database):
#Id
#GeneratedValue
#Column(name = "IDTESTOBJEKT", unique = true, nullable = false)
public Integer getIdtestobjekt() {
return this.idtestobjekt;
}