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h2 database persists data but resets on application start

I have a basic test for an embedded database that I'm trying to get working for a java project. As it stands now I am able to save rows to the database with my entity repository object, and after the app finishes running, I can connect to the database with intellij and see those rows are still there. But then, if I comment out the save methods and run it again, when I check the database after it finishes, the database is empty.
Entity
package closet.utilities.entities;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name = "outfits")
public class Outfit {
#Id
#Column(name = "id")
String id;
#Column(name = "inv_name")
String invName;
#Column(name = "display_name")
String displayName;
#Column(name = "owner")
String owner;
public Outfit() {
}
public Outfit(String id, String invName, String displayName, String owner) {
this.id = id;
this.invName = invName;
this.displayName = displayName;
this.owner = owner;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getInvName() {
return invName;
}
public void setInvName(String invName) {
this.invName = invName;
}
public String getDisplayName() {
return displayName;
}
public void setDisplayName(String displayName) {
this.displayName = displayName;
}
public String getOwner() {
return owner;
}
public void setOwner(String owner) {
this.owner = owner;
}
#Override
public String toString() {
return "Outfit{" +
"id='" + id + '\'' +
", invName='" + invName + '\'' +
", displayName='" + displayName + '\'' +
", owner='" + owner + '\'' +
'}';
}
}
Repository
package closet.utilities.repositories;
import closet.utilities.entities.Outfit;
import javax.persistence.EntityManager;
import java.util.List;
import java.util.Optional;
public class OutfitRepository {
private EntityManager entityManager;
public OutfitRepository(EntityManager entityManager) {
this.entityManager = entityManager;
}
public Optional<Outfit> findById(String id) {
Outfit outfit = entityManager.find(Outfit.class, id);
return outfit != null ? Optional.of(outfit) : Optional.empty();
}
public List<Outfit> findAll() {
return entityManager.createQuery("from Outfit").getResultList();
}
public Optional<Outfit> save(Outfit outfit) {
try {
entityManager.getTransaction().begin();
entityManager.persist(outfit);
entityManager.getTransaction().commit();
return Optional.of(outfit);
} catch (Exception e) {
// TODO logging
e.printStackTrace();
}
return Optional.empty();
}
}
main method
package closet.utilities;
import closet.utilities.entities.Outfit;
import closet.utilities.repositories.OutfitRepository;
import org.hibernate.Session;
import org.hibernate.Transaction;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import java.util.List;
public class Runnable {
public static void main(String[] args) {
// Create our entity manager
EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("closet");
EntityManager entityManager = entityManagerFactory.createEntityManager();
Outfit outfit = new Outfit("Ramesh", "Fadatare", "rameshfadatare#javaguides.com", "");
Outfit outfit1 = new Outfit("John", "Cena", "john#javaguides.com", "");
OutfitRepository outfitRepository = new OutfitRepository(entityManager);
//outfitRepository.save(outfit);
//outfitRepository.save(outfit1);
List<Outfit> outfits = outfitRepository.findAll();
for (Outfit o : outfits) {
System.out.println(o.getInvName());
}
}
}
persistence.xml
<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" xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="closet" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<class>closet.utilities.entities.Outfit</class>
<properties>
<property name="javax.persistence.jdbc.driver" value="org.h2.Driver" />
<property name="javax.persistence.jdbc.url" value="jdbc:h2:./data/closet" />
<property name="javax.persistence.jdbc.user" value="sa" />
<property name="javax.persistence.jdbc.password" value="" />
<property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
<property name="hibernate.hbm2ddl.auto" value="create-drop" />
<property name="show_sql" value="true"/>
<property name="hibernate.temp.use_jdbc_metadata_defaults" value="false"/>
</properties>
</persistence-unit>
</persistence>
hibernate.cfg.xml
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- JDBC Database connection settings -->
<property name="connection.driver_class">org.h2.Driver</property>
<property name="connection.url">jdbc:h2:./data/closet</property>
<property name="connection.username">sa</property>
<property name="connection.password"></property>
<!-- JDBC connection pool settings ... using built-in test pool -->
<property name="connection.pool_size">1</property>
<!-- Select our SQL dialect -->
<property name="dialect">org.hibernate.dialect.H2Dialect</property>
<!-- Echo the SQL to stdout -->
<property name="show_sql">true</property>
<!-- Set the current session context -->
<property name="current_session_context_class">thread</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">create-drop</property>
<!-- dbcp connection pool configuration -->
<property name="hibernate.dbcp.initialSize">5</property>
<property name="hibernate.dbcp.maxTotal">20</property>
<property name="hibernate.dbcp.maxIdle">10</property>
<property name="hibernate.dbcp.minIdle">5</property>
<property name="hibernate.dbcp.maxWaitMillis">-1</property>
<mapping class="closet.utilities.entities.Outfit" />
</session-factory>
</hibernate-configuration>
I'm just following this tutorial here as a guide to just figure out how to get it all working. I can't see what I'm doing wrong based on that.

You use:
<property name="hbm2ddl.auto">create-drop</property>
As it is stated in the documentation:
create-drop
Drop the schema and recreate it on SessionFactory startup. Additionally, drop the schema on SessionFactory shutdown.
So, this is expected behaviour.

Manual dynamic enhancement with openjpa on intellij

I am trying to use openjpa and mysql to persist a single class, nothing dramatic really.
Attempt to cast instance "xxx" to PersistenceCapable failed. Ensure that it has been enhanced.
So I looked around and found this
https://openjpa.apache.org/builds/2.2.1/apache-openjpa/docs/ref_guide_pc_enhance.html
where they suggest the use of
java -javaagent:/home/dev/openjpa/lib/openjpa.jar com.xyz.Main
Now I added this to my VM-Options in my intellij runtime configurations:
-javaagent:/home/xxx/Downloads/apache-openjpa-3.1.2/openjpa-all-3.1.2.jar main.java.entity.Post
But it does not seem to recognise the class:
You have enabled runtime enhancement, but have not specified the set of persistent classes. OpenJPA must look for metadata for every loaded class, which might increase class load times significantly.
I thought the 2nd argument for javaagent is me specifiying the class but I am wrong.
This is my persistence.xml:
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.2"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_2.xsd">
<!-- Define persistence unit -->
<persistence-unit name="post">
<class>main.java.entity.Post</class>
<properties>
<property name="openjpa.DynamicEnhancementAgent" value="true"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/DSTEST" />
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.user" value="xxx" />
<property name="javax.persistence.jdbc.password" value="xxx" />
</properties>
</persistence-unit>
And this is my entity:
package main.java.entity;
import javax.persistence.Entity;
import javax.persistence.Id;
#Entity (name="post")
public class Post {
#Id
private Integer postid;
private String user;
private Integer datum;
private String inhalt;
public Integer getPostid() {
return postid;
}
public void setPostid(Integer postid) {
this.postid = postid;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public Integer getDatum() {
return datum;
}
public void setDatum(Integer datum) {
this.datum = datum;
}
public String getInhalt() {
return inhalt;
}
public void setInhalt(String inhalt) {
this.inhalt = inhalt;
}
}
I am using Intellij on Ubuntu.

No persistence provider for Entity Manager with Tomcat

I'm trying to to develop a simple rest API project with Java and Tomcat. The HTTP request works correctly, but I'm figuring out a lot of problem by implementing a database MySQL to store data. This is my persistence.xml file, that is located in Java Resources/META-INF:
<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="PERSISTENCE">
<description> Hibernate JPA Configuration Example</description>
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<class>com.resourceserver.Person</class>
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
<property name="javax.persistence.jdbc.url"
value="jdbc:mysql://localhost:3306/RESTResourceServer" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password" value="password" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.hbm2ddl.auto" value="update" />
</properties>
</persistence-unit>
This is my PersonDAO.java and JPAUtil.java class:
public class PersonDao {
EntityManager entityManager;
public PersonDao() {
entityManager = JPAUtil.getEntityManagerFactory().createEntityManager();
}
public void storePerson(Person person) {
entityManager.persist(person);
// people.add(person);
}
public void deletePerson(Person person) {
entityManager.remove(person);
// people.remove(person);
}
public Person findPersonId(int id) {
/*
* for (Person person : people) { if (person.getId() == id) { return person; } }
*/
return null;
}
#SuppressWarnings("unchecked")
public List<Person> getAllUsers() {
Query query = entityManager.createQuery("Select p From People p ");
return query.getResultList();
// return people;
}
}
public class JPAUtil {
private static final String PERSISTENCE_UNIT_NAME = "PERSISTENCE";
private static EntityManagerFactory factory;
public static EntityManagerFactory getEntityManagerFactory() {
if (factory == null) {
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
}
return factory;
}
public static void shutdown() {
if (factory != null) {
factory.close();
}
}
}
And in my Endpoint I simple use PersonDao persona = new PersonDao() to perform the operations; where am I wrong?

You are missing the persistence provider (no surprise there!)
Most likely you have added the JPA API as a dependency but forgot to add a concrete implementation like Hibernate or EclipseLink. This means you can compile the whole thing because the interfaces for JPA are there but there are not implementing classes.

Creation of the database tables with Hibernate

people!
I made a small project using Servlets / JBoss / Hibernate / Mysql.
I put Hibernate to generate tables automatically. My question is only that: When these table are generated? Tables should be created when I rise the JBoss or when I call the servlet in the browser?
Because I realized that they are created only when I call one of my Servlets, and I imagined they would be created when I rise the JBoss.
Sorry if it's silly.
Here is my Class:
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name="estacoes")
public class Estacao {
#Id
#GeneratedValue
private int id;
private String nome;
private String endereco;
private String temperatura;
private String energia;
private String porta;
private String sinal;
private String bateria;
...getters/setters...
My 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_2_0.xsd"
version="2.0">
<persistence-unit name="arduinoserver">
<!-- provedor/implementacao do JPA -->
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<non-jta-data-source>java:jboss/datasources/MysqlDS</non-jta-data-source>
<!-- entidade mapaeada -->
<class>arduinoserver.beans.Estacao</class>
<properties>
<!-- propriedades do hibernate -->
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.hbm2ddl.auto" value="update" />
<property name="hibernate.connection.charSet" value="UTF-8" />
</properties>
</persistence-unit>
And my DAO:
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import arduinoserver.beans.Estacao;
public class EstacaoDAO {
protected EntityManager entityManager;
public EstacaoDAO() {
entityManager = getEntityManager();
}
private EntityManager getEntityManager() {
EntityManagerFactory factory = Persistence.createEntityManagerFactory("arduinoserver");
if(entityManager == null) {
entityManager = factory.createEntityManager();
}
return entityManager;
}
public Estacao getById(final int id) {
return entityManager.find(Estacao.class, id);
}
#SuppressWarnings("unchecked")
public List<Estacao> findAll() {
return entityManager.createQuery("FROM estacoes").getResultList();
}
public void persist(Estacao estacao) {
try {
entityManager.getTransaction().begin();
// entityManager.persist(estacao);
entityManager.merge(estacao);
entityManager.getTransaction().commit();
} catch(Exception ex) {
ex.printStackTrace();
entityManager.getTransaction().rollback();
}
}
}

As far as I know Hibernate creates the tables when the SessionFactory is created. The application server doesn't automatically create one on its own, therefor the tables are usually not created on the server start.

Problems building up Java project with JPA

I am trying to get a javax.persistence running, but I get erros.
I built up a little project for testing, creating an entity class, the persistence.xml, and the running process:
Entity class:
package glasses;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Id;
#Entity
public class Hund implements Serializable {
#Id
private long id;
private String name;
private String typ;
public long getId() {
return this.id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public String getTyp() {
return this.typ;
}
public void setTyp(String typ) {
this.typ = typ;
}
}
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="GlassesPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/glasses?zeroDateTimeBehavior=convertToNull"/>
<property name="javax.persistence.jdbc.password" value="mypwd"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
</properties>
</persistence-unit>
</persistence>
Error message:
Caused by: java.lang.IllegalArgumentException: Object: glasses.Hund#5d2e0422 is not a known entity type.
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4228)
at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:496)
at glasses.FXMLDocumentController.handleButtonAction(FXMLDocumentController.java:48)
... 54 more
Does anyone know the problem? Is there anything wrong in the Hund-class? Or in the persistence.xml?

Use your Hund class inside your persistence.xml like following example. Just place it between the properties and the persistence-unit tags.
</properties>
<class>glasses.Hund</class>
</persistence-unit>

If you don't want to list in the persistence.xml all your entities you can add the following line in the persistence.xml:
<exclude-unlisted-classes>false</exclude-unlisted-classes>