I have a standalone java application, which uses JPA for its persistence.
Right now I have a persistence.xml in META-INF.My application is currently in development.
My question is that if I move from development to the next envirnoment, say QA. I have to modify the persistence.xml and rebuild the jar. Is this the right way to go about it ?
If not,if I move the connection properties to a different file, where should this file be placed?
<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="pu1" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>ClassA</class>
<class>ClassB</class>
<class>ClassC</class>
<class>ClassD</class>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect" />
<property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.connection.username" value="username" />
<property name="hibernate.connection.password" value="password" />
<property name="hibernate.connection.url"
value="url" />
<property name="hibernate.max_fetch_depth" value="3" />
<property name="hibernate.archive.autodetection" value="class" />
</properties>
</persistence-unit>
</persistence>
Thanks in advance !
That's a good question. Normally, you put all these environment settings in an external file, say application.properties, and pass the location to it to the JVM when you start your application (e.g. -Dconfig.location=/conf/)
Then you should find a way to get the externalized properties into your EntityManagerFactory. You can't do that in persistence.xml, you can only hard-code things there. But you can do it when creating the entity manager factory by passing vendor properties.
If using a framework like spring, for example, this is easier to do, as spring provides a factory bean for the entity manager. Otherwise you should handle it yourself. Here's the relevant bit from spring:
provider.createEntityManagerFactory(persistenceUnitInfo, getJpaPropertyMap())
Related
I have gone though https://www.playframework.com/documentation/2.5.x/JavaJPA
But it doesn't feel like a stardard way. I would like fill my jdbc connection in persistence.xml instead of application.conf
like this
<?xml version="1.0" encoding="UTF-8" ?>
<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="TestPersistence"
transaction-type="RESOURCE_LOCAL">
<class>com.example.pojo.Employee</class>
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<non-jta-data-source>DefaultDS</non-jta-data-source>
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.url"
value="jdbc:mysql://localhost:3306/jpadb" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password"
value="mukesh" />
<!-- EclipseLink should create the database schema automatically -->
<property name="eclipselink.ddl-generation" value="create-tables" />
<property name="eclipselink.ddl-generation.output-mode"
value="database" />
</properties>
</persistence-unit>
</persistence>
instead of filling the jdbc connection in application.conf like
db.default.driver=com.mysql.jdbc.Driver
db.default.url="jdbc:mysql://localhost:3306/jpadb"
db.default.user=root
db.default.password="mukesh"
db.default.jndiName=DefaultDS
jpa.default=TestPersistence
Also if there is no other way to get jdbc connection in persistence.xml how can we define more than one jdbc connection in application.conf. like if i have a mysql for users and oracle db for posts.
NOTE: the source code posted are just dummy copied from public domain to show the briefly problem.
You don't have to use Play's DB module. You can have your own module defined, and load your database connection and run it in isolation.
I would check out https://github.com/playframework/play-isolated-slick as an example -- here the UserDAO is bound through to SlickDAO in the Play module:
https://github.com/playframework/play-isolated-slick/blob/master/modules/play/app/Module.scala#L19
and the database provider is provided:
https://github.com/playframework/play-isolated-slick/blob/master/modules/play/app/Module.scala#L27
but you don't have to use Database.forConfig("myapp.database") -- you can define any config you feel like.
I am involved in writing a project which requires servlet->database connection. I am collaborating with another person who have designed a database using HyperSQL (hsqldb), I am now trying to merge my project with his by adding his code to mine.
Further to my issue though. When I copy the code, it works, usually. I have few methods that use the data from the database and compare them with user input.
When attempting to connect to the database, I would randomly succeed or fail, getting the following error ;
Unable to acquire a connection from driver [null]
I of course initialise a driver ;
Class.forName("org.hsqldb.jdbcDriver").newInstance();
Now, when running my method, it sometimes succeeds, and sometimes fails, here is the XML file for the DB;
<?xml version="1.0" encoding="UTF-8"?>
<!--
Creates both the HyperSQL databases using hibernate. No password or username is set.
-->
<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="monsters" transaction-type="RESOURCE_LOCAL">
<class>databaseManagement.Monster</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
<property name="hibernate.connection.username" value=""/>
<property name="hibernate.connection.password" value=""/>
<property name="hibernate.connection.url" value="jdbc:hsqldb:monsters"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
</properties>
</persistence-unit>
<persistence-unit name="users" transaction-type="RESOURCE_LOCAL">
<class>databaseManagement.User</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
<property name="hibernate.connection.username" value=""/>
<property name="hibernate.connection.password" value=""/>
<property name="hibernate.connection.url" value="jdbc:hsqldb:users"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
</properties>
</persistence-unit>
</persistence>
Probably an attempt is made to open the database in a readonly directory.
You need to specify a username for both persistence units. The default username is "SA".
The file path of the database that you specify in the URL is relative. It resolves to the execution directory. As you are developing a web application, you need to specify a directory that can be written to.
One way of doing this is by including a variable in the path, such as "jdbc:hsqldb:file:{$directorypath}/monsters" where the directorypath is the name of the web application's data dirctory, as specified in your web.xml file.
I'm using Spring in Tomcat for my webapp. My datasources are built in Spring then published to JNDI using org.springframework.jndi.JndiTemplate. This is clunky for a few reasons, but my main problem is that it's difficult to control the database being used (which I want to do for testing). Is it possible to use JPA without using JNDI as a lookup service? Ideally, I'd be able to provide the data sources directly to JPA, or through some other method that doesn't rely on a container for the implementation (I have investigated JNDI implementations that aren't provided by a container, but they're not right for my needs).
You can specify a datasource in your spring configuration file. Here is an excerpt from mine which uses a MySql Database. To view the full configuration file and project view the source on GitHub.
<!-- Database -->
<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/to_thought_tutorial" />
<property name="username" value="tutorial" />
<property name="password" value="tutorial" />
</bean>
<!-- Entity Manager -->
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="datasource" />
<property name="persistenceUnitName" value="tothought-tutorial" />
</bean>
I would also encourage you to visit my blog which contains a video describing how to setup a datasource: http://tothought.cloudfoundry.com/post/4
The Spring documentation also includes examples of how to setup a datasource that does not rely upon JNDI: http://static.springsource.org/spring/docs/3.2.x/spring-framework-reference/html/jdbc.html#jdbc-datasource
You can define a data source connection directly in your persistence.xml for any given persistence unit:
<?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="BlahBlah" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
<property name="hibernate.connection.url" value="jdbc:mysql://localhost/db_name"/>
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
<property name="hibernate.connection.username" value="root"/>
<property name="hibernate.connection.password" value="xxx"/>
</properties>
</persistence-unit>
</persistence>
If you're not using Hibernate, you can lookup your providers properties, or use the JPA2 standard properties javax.persistence.jdbc.user, javax.persistence.jdbc.password, javax.persistence.jdbc.url etc.
I've been searching around and haven't been able to find a working fix. My persistence.xml file is located in /src/META-INF/persistence.xml, which from looking around, this is the correct location for it.
I'm using glassfish as the server, and I keep getting the following:
javax.persistence.PersistenceException: No Persistence provider for EntityManager named pers
Here is my persistence file:
<?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="pers" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>cs.ee.assignment2.Client</class>
<properties>
<property name="hibernate.hbm2ddl.auto" value="update" />
<property name="hibernate.archive.autodetection" value="class, hbm" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" />
<property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/assignment2" />
<property name="hibernate.connection.password" value="root" />
<property name="hibernate.connection.username" value="root" />
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
</properties>
</persistence-unit>
</persistence>
Any ideas on what the problem could be would be greatly appreciated.
Hmm.. make sure you are using PeristenceUnit not context in your entity class: see http://openejb.apache.org/jpa-concepts.html
Switch to "transaction" just to see if it fails too.
Also sometimes the old classes are not unloaded from the server properly if you are doing redeployment, you may have to shut it down and restart after redeploy.
I'm having some problem with EclipseLink. I'm using GlassFish v3.1 and I'm trying to use EclipseLink for my persistence layer. I followed all tutorials available on the Eclipse wiki without luck. My persistence.xml file cannot be parsed and I receive this error while trying to create the EntityManagerFactory:
org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while processing persistence.xml from URL: bundle://307.1:1/
Here is my persistence.xml located in /WEB-INF/classes/META-INF/:
<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="generic">
<class>com.generic.domain.Service</class>
<properties>
<!-- Embedded MySQL Login -->
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306"/>
<!-- TODO: replace with connection pool -->
<property name="javax.persistence.jdbc.userid" value="root"/>
<property name="javax.persistence.jdbc.password" value=""/>
<property name="eclipselink.target-database" value="MySQL"/>
<property name="eclipselink.jdbc.read-connections.min" value="1"/>
<property name="eclipselink.jdbc.write-connections.min" value="1"/>
<property name="eclipselink.jdbc.batch-writing" value="JDBC"/>
<!-- Logging Settings -->
<property name="eclipselink.logging.level" value="FINE" />
<property name="eclipselink.logging.thread" value="false" />
<property name="eclipselink.logging.session" value="false" />
<property name="eclipselink.logging.exceptions" value="true" />
<property name="eclipselink.logging.timestamp" value="false"/>
</properties>
</persistence-unit>
</persistence>
I added this line to my MANIFEST.MF:
JPA-PersistenceUnits: generic
I can now confirm that it's a bug in EclipseLink. The work around to your problem is to either get hold of EntityManagerFactory using JNDI lookup or #PersistenceUnit instead of doing Persistence.createEntityManagerFactory().
1) It looks like you are trying to use OSGi/JPA from your WAB. Correct?
2) Can you tell if you have installed any new eclipselink bundles in your system? If so, what are they?
3) Can you provide stack trace?