JPA 2 Training Overview
Accelebrate's JPA 2 Training: Introduction to the Java™ Persistence API 2 class teaches attendees how to implement JPA for data persistence. JPA 2 is a standard feature of Java EE 6 and later, but can also be used with Java SE applications.
Location and Pricing
Accelebrate offers instructor-led enterprise training for groups of 3 or more online or at your site. Most Accelebrate classes can be flexibly scheduled for your group, including delivery in half-day segments across a week or set of weeks. To receive a customized proposal and price quote for private corporate training on-site or online, please contact us.
In addition, some courses are available as live, instructor-led training from one of our partners.
Objectives
- Understand the JPA architecture
- Create JPA based applications
- Understand and use JPA to map persistent objects to the database
- Create JPA persistence units, and understand JPA persistence contexts
- Use the JPA EntityManager
- Work with queries and JPQL (Java Persistence Query Language), as well as the Criteria API (JPA 2)
- Understand and work with collections and associations
- Value and Entity Types
- Bidrectional and unidirectional
- 1-1, 1-N, N-N
- Use versioning support for optimistic locking
- Map inheritance hierarchies using JPA
- Performance tune your JPA applications
- Understanding JPA transaction support
- Understand the relationship between JPA / EJB3
- Use JPA entities from session beans
- Be familiar with Spring support for JPA
Prerequisites
All attendees must have substantial prior Java development and relational database experience.
Outline
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Introduction to Java Persistence API (JPA)
- Overview
- Persistence Layers, Object-Relational Mapping (ORM), JDBC
- JPA Overview
- Mapping with JPA
- Entities and @Entity, ids and @Id
- Generated Id Values
- Basic Mapping Types
- Persistence Unit and EntityManager
- Persisting to the DB, the EntityManager API
- Persistence Units, Config, Persistence Context
- Retrieving Persistent Entities with find()
- More About Mappings
- Default Mappings, @Basic, @Column
- Field vs. Property Access
- Temporal (Date/Time) Mappings
- Logging Options (Provider based)
Updates and Queries
- Inserting and Updating - Persisting new Entities, Updating an Instance, Removing an Instance
- Querying and JPQL
- Entity Based Queries, SELECT, WHERE
- Query Interface, Executing Queries, Generic Queries (JPA 2)
- JPQL Operators, Expressions, and Parameters
- Named Queries
- Additional Query Capabilities
- Projection query, Ordering, Aggregate Query, Build Update and Delete
- Embedded Objects
- @Embeddable, @Embedded
- Defining and using Embedded Objects
- Compound Primary Keys - @EmbeddedID, @IDClass, Defining Compound Keys
The Persistence Lifecycle
- Transaction Overview and Transactions in JPA
- Transaction Overview
- EntityTransaction API (including JTA and resource-local EntityManager)
- The Persistence Lifecycle
- JPA Entity States (New, Managed, Detached, Removed), and Entity State Diagram
- Persistence Context - Lifespan, Propagation
- Synchronization to the DB
- Versioning and Optimistic Locking
- Overview, Detached Instances
- Versioning, @Version, Optimistic Locking
- Lifecycle Callbacks
- @PrePersist, @PostPersist, etc.
- Entity Listeners, @Entity Listeners
Entity Relationships
- Relationships Overview: Object Relationships, Participants, Roles, Directionality, Cardinality
- Relationship Mapping
- Mapping Overview (1-1, 1-N, N-1, N-N)
- Unidirectional and Bidirectional
- @ManyToOne, @OneToMany, Table Structures
- Relationship Inverse - Owning Side
- Collection Types (List, Set, etc)
- Cascading Over Relationships (including orphanRemoval - JPA 2)
- @ManyToMany, @OneToOne
- Lazy and Eager Loading
- Queries Across Relationships (Inner Joins, Outer Joins, Fetch Joins)
- Entity Inheritance Mapping
- Overview
- Single Table Mapping
- Joined (Table per Subclass) Mapping
- Table per Concrete Class Mapping
- Pros and Cons
Element Collections (JPA 2)
- Overview, Collections of Value Objects, @ElementCollection, @CollectionTable
- Using Element Collections
- Collections of Embeddables
Criteria API (JPA 2)
- Overview of the Criteria API
- Path Expressions, Building Queries (CriteriaBuilder, CriteriaQuery, Subquery, Predicate, Expression, Order, Selection, Join)
- Executing Queries and Accessing Results
Additional JPA Capabilities
- XML Mapping Files
- Bean Validation (JPA 2)
- Best Practices
- Primary Keys, Named Queries, Lazy/Eager Loading, Transactional Semantics, Encapsulation, Report Queries
Integration
- Data Access Objects (DAO) and Java SE Integration
- DAO Overview
- JpaUtil Class for EntityManager management in Java SE
- Lifecycle Considerations
- Integration with EJB
- Using JPA with Session Beans
- Container Managed (Injected) Entity Manger
- JTA Transactions and Lifecycle Considerations
- Extended Persistence Contexts
- Using JPA with Java Web Apps
- Using EntityManager in Web apps - request scoping
- Lazy Loading - Open EntityManager in View Pattern
- Integration with Spring
- Injection of EntityManger, EntityManagerFactory
- LocalEntityManager FactoryBean
- JPA/Spring Based DAO
Conclusion
Training Materials
All JPA training students receive comprehensive courseware.
Software Requirements
- A recent version of Windows, macOS, or Linux with at least 8 GB RAM
- JDK 8 or later
- The Java tool the students are likely to use after the class (Eclipse or IntelliJ IDEA are recommended)
- Other free software - please contact us if you have purchased this class
