Persistence

Ennovation – Behind the Products

Anish Alex, CTO

• Closest native language support– Serialization

• Lifecycle– Begins and Ends with JVM

• Identity– Equals / Hashcode / Memory Location

• Data Types– Int/long/string..

• RDBMS– Long term persistence / Primary Key – SQL– VARCHAR / NUMBER

2 Evolvus Solutions. Proprietary and Confidential, do not copy, duplicate or distribute.

Java Persistence Problem

• Object Relational Mappers – ORM’s– Map Java objects to Relational database

table records e.g.– Top Link / Hibernate

• Java Data Objects (JDO)– Apache jdo

• JDBC• Java Persistence API (JPA)

– Hibernate– Top Link– Open JPA

• EJB• Custom


Java Persistence Technologies

Java Persistence Technologies

Evolvus Solutions. Proprietary and Confidential, do not copy, duplicate or distribute.4

HibernateRelational Persistence for Java

• XML file to map POJO to Tables• Configuration• Classes to bootstrap the framework• JPA Implementation


Hibernate - Relational Persistence for Java

Sample CodeORM

• Generators– native– increment– sequence– assigned– hilo / identify / uuid.hex / uuid.string / foreign

• Version– Prevents invalid overwrites

• Property– String – specify length– BigDecimal – specify precision/scale– Date / Timestamp / Long - nothing to specify


Hibernate ORM

• References– http://www.mkyong.com/tutorials/hibernate-

tutorials/– http://docs.jboss.org/hibernate/orm/3.3/

reference/en/html/index.htmlPrevents invalid overwrites

– Sample code - http://codeserver/demo-repository/svndemo/anisht/trunk/training/hibernate


Hibernate ORM

• To-Do– One-to-Many using foreign keys– Many-to-One– Many-to-One using foreign keys– One-to-One– Run the same examples against SQL Server


Hibernate ORM

THANK YOU !!

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Persistence

Technology

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