Group items tagged

jboss.as.jpa.adapterModule

jboss.as.jpa.adapterClass

org.jboss.as.jpa.hibernate3.HibernatePersistenceProviderAdaptor

Working with other persistence providers

A project to build integration for persistence providers like EclipseLink, is here.

Troubleshooting

“org.jboss.as.jpa” logging can be enabled to get the following information: INFO - when persistence.xml has been parsed, starting of persistence unit service (per deployed persistence.xml), stopping of persistence unit service DEBUG - informs about entity managers being injected, creating/reusing transaction scoped entity manager for active transaction TRACE - shows how long each entity manager operation took in milliseconds, application searches for a persistence unit, parsing of persistence.xml

To enable TRACE, open the as/standalone/configuration/standalone.xml (or as/domain/configuration/domain.xml) file. Search for <subsystem xmlns="urn:jboss:domain:logging:1.0"> and add the org.jboss.as.jpa category

Packaging the Hibernate 3.5 or greater 3.x JPA persistence provider with your application

jboss.as.jpa.providerModule needs to be set to hibernate3-bundled.

<property name="jboss.as.jpa.providerModule" value="hibernate3-bundled" />

Sharing the Hibernate 3.5 or greater JPA persistence provider between multiple applications

Applications can share the same Hibernate3 (for Hibernate 3.5 or greater) persistence provider by manually creating an org.hibernate:3 module (in the AS/modules folder). Steps to create the Hibernate3 module:

<property name="jboss.as.jpa.providerModule" value="org.hibernate:3" />

if the value is a Basic but the key is an Entity a

mapping is used.

if the key is a Basic but the value is an Entity a

mapping is still used

a three way join table, can be mapped using a

used to define a map relationship where the

If the JPA entities still do not look right, try to apply some JPA tricks like mapping a JPA-entity to several tables, or even map JPA-entities to DB-views, to improve the situation

Rename the classes into some more meaningful. The attribute, class names are in general everything but not fluent

Junit. Purpose: JPA mapping verification

Thinking In Structs Not Objects

12 Tips On JPA Domain Modelling

Execute the "Unit" tests after every change

even better get rid of them

domain objects are

bean-validation JPA, Bean Validation Shows how to use Arquillian to test Bean Validation

ejb-security Security, EJB Shows how to use Java EE Declarative Security to Control Access to EJB 3

payment-cdi-event CDI Demonstrates how to use CDI 1.0 Events

richfaces-validation RichFaces Demonstrates RichFaces and bean validation

ejb-in-war JSF, WAR, EJB Packages an EJB JAR in a WAR

greeter EJB, JPA, JSF, JTA, CDI Demonstrates the use of CDI 1.0, JPA 2.0, JTA 1.1, EJB 3.1 and JSF 2.0

helloworld-mdb EJB, MDB, JMS Demonstrates the use of JMS 1.1 and EJB 3.1 Message-Driven Bean

helloworld-rs JAX-RS, CDI Demonstrates the use of CDI 1.0 and JAX-RS

kitchensink BV, EJB, JAX-RS, JPA, JPA, JSF, CDI

servlet-async CDI, EJB, Servlet Demonstrates CDI, plus asynchronous Servlets and EJBs

servlet-security Security, Servlet Demonstrates how to use Java EE declarative security to control access to Servlet 3

shopping-cart EJB Demonstrates a stateful session bean

tasks Arquillian, JPA Demonstrates testing JPA using Arquillian

UserService

UserDao

FacebookWS

User u

UserService uses UserDAO and FacebookWS

but don’t know how those dependencies are instantiated

And you shouldn’t really care, all that is important is that UserService depends on dao and webservice object.

BDD template given-when-then) tests are easy to read

@Entity

public class User

calling new User(“someName”,”somePassowrd”, “someOtherName”, “someOtherPassword”) becomes hardly readable and maintainable

code duplication

Maintaining this code would turn into a nightmare in no time

running the code above will throw an exception by the JPA provider,

Joshua Blooch gives fine example of builder pattern.

Instead of making the desired object directly, the client calls a constructor (or static factory) with all of the required parameters and gets a builder object. Then the client calls setter-like methods on the builder object to set each optional parameter of interest. Finally, the client calls a parameterless build method to generate the object, which is immutable. The builder is a static member class of the class it builds.

Coffee

public static class Builder

Builder(CoffeeType type, int cupSize)

Builder withMilk()

Coffee build()

Coffee(this)

private Coffee(Builder builder)

Coffee coffee = new Coffee.Builder(CoffeeType.Expresso, 3).withMilk().build();2}

especially if most of those parameters are optional.

For all entity attributes I create private fields

those that are obligatory become parameters for the public constructor

parameter-less constructor, I create one, but I give him

protected access level

protected

JPA 2.0, still contains only a subset of the features supported by many database vendors

features not supported in JP QL.

performance required by an application is to replace the JP QL query with a hand-optimized SQL version. This may be a simple restructuring of the query that the persistence provider was generating, or it may be a vendor-specific version that leverages query hints and features specific to a particular database.

recommend avoiding SQL initially if possible and then introducing it only when necessary

benefits of SQL query support is that it uses the same Query interface used for JP QL queries. With some small exceptions that will be described later, all the Query interface operations discussed in previous chapters apply equally to both JP QL and SQL queries.

keep application code consistent because it needs to concern itself only with the EntityManager and Query interfaces.

An unfortunate result of adding the TypedQuery interface in JPA 2.0 is that the createNativeQuery() method was already defined in JPA 1.0 to accept a SQL string and a result class and return an untyped Query interface

consequence is that when the createNativeQuery() method is called with a result class argument one might mistakenly think it will produce a TypedQuery, like createQuery() and createNamedQuery() do when a result class is passed in.

@NamedNativeQuery

resultClass=Employee.class

The fact that the named query was defined using SQL instead of JP QL is not important to the caller

SQL Result Set Mapping

JPA provides SQL result set mappings to handle these scenarios

A SQL result set mapping is defined using the @SqlResultSetMapping annotation. It may be placed on an entity class and consists of a name (unique within the persistence unit) and one or more entity and column mappings.

entities=@EntityResult(entityClass=Employee.class)

@SqlResultSetMapping

Multiple Result Mappings

A query may return more than one entity at a time

The SQL result set mapping to return both the Employee and Address entities out of this query

emp_id, name, salary, manager_id, dept_id

address_id, id, street, city, state, zip

order in which the entities are listed is not important

ntities={@EntityResult(entityClass=Employee.class), @EntityResult(entityClass=Address.class)}

queries polymorphic

Introduce the Resource class

new type, Dvd

Query object that can then be executed to return a list of entities or a single entity.

Keeping the query and the code that sets these parameters together makes them both easier to understand

Maven 3 is highly recommended but Maven 2.2 should also work

CDI archetype defines an embedded GlassFish run configuration

mvn embedded-glassfish:run

Enhancements in EntityManagerFactory Interface

Enhancements in EntityManager Interface

detach

getEntityManagerFactory

deploy the example by right clicking on the jboss-as-login project, and choosing Run As -> Run On Server

src/main/webapp directory

beans.xml and face-config.xml tell JBoss AS to enable CDI and JSF for the application

don't need a web.xml

src/main/resources

persistence.xml, which sets up JPA, and import.sql which Hibernate, the JPA provider in JBoss AS, will use to load the initial users into the application when the application starts

"JOINED" strategy

each entity in the inheritance hierarchy has its own table and that the table of each class only contains columns for that class

after the database DELETE has occurred

before the transaction is committed

after the database UPDATE has occurred

before the transaction is committed

after the database UPDATE has occurred

before the transaction is committed

after the database INSERT has occurred

before the transaction is committed

if you run them within one transaction like the code below does, you will find that the item list while be empty:

to keep bidirectional associations in sync, JPA leaves more up to the developer.