HIBERNATE Report

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HIBERNATE Report
Object/Relational Mapping

• SHAOJIAN ZHU CHIH-HUNG CHO

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Lazy Initialization

• Class initialization needs time
• Until we need it, we initialize it.
• This until-use-initialize method is lazy
  initialization
• Advantage
• Save time and computing for wasted class
  initialization

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Fine-grained vs Coarse-grained

• Fine-grained PO (persistant object)
• Control the one-to-one mapping of data and table
  column
• Coarse-grained PO
• Using multiple coarse-grained PO to control the
  whole data management
• Users can use Coarse-grained PO to indirectly
  call the Fine-grained PO to carry out the
  data-management task
• Disadvantage for Coarse-grained PO
• As a whole system, so lazy initialization is
  impossible.
• It limits the use of inheritance and polymorphism
  in the coding.
• For Hibernate.
• Supports both of Fine-grained vs Coarse-grained
• Provide more flexibility.

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HBM hibernate mapping files

• ltclassgt
• matches the pojo to table
• ltidgt
• identifies the PK
• There are many different types of generators
• Increment
• native
• ltpropertygt mapping a class field to a table
  column
• ltsetgt subclass
• carDTO.hbm.xml
• But, this task seems time-consuming
• Is there any automatic way to generate mapping
  file?

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XDoclet can help

• Automate the generating of the
• mapping xml file.
• By adding comments to your pojo.
• Example
• carDTO.java

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Service Descriptor file

• Hibernate MBean Service Descriptor file
• ltmbeansgt
• Names the service and specifies the implementing
  class
• ltDialectgt
• tells Hibernate which type of database it is
  talking to.
• ltSessionFactoryNamegt
• the global JNDI name for the services
  sessionfactory (we need it in jboss-web.xml)
• ltCacheProvideClassgt
• element tells Hibernate what caching strategy to
  use!
• ..
• See Example
• Hibernate-service.xml

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Create a HAR

• Hibernate applications are bundled up in
• Hibernate Archive (HAR)
• See har_build.xml

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Add the HAR to EAR

• HARs are not standard parts of a J2EE EAR file
• JBoss looks for jboss-app.xml
• See example jboss-app.xml
• Now lteargt task now includes this file along with
  the traditional application.xml
• See example ear_build.xml

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Create JNDI Lookup

• Create a JNDI reference
• ltres-ref-namegt is the local name
• ltjndi-namegt is global which matches the setting
  in hibernate-service.xml
• See jboss-web.xml
• web.xml file
• Generated automatically by XDoclet
• See ControllerServlet.java

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Hibernate Checklist

• Add Hibernate tags to the CarDTO
• Created a Hibernate MBean service descriptor
• Bundled these files up in a HAR
• Created a JNDI reference

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CRUD

• CRUD (Create,Read,Update,and Delete)
• are the four basic functions of persistent
  storage,
• a major part of nearly all computer software.
  Sometimes
• CRUD is expanded with the words retrieve or
  destroy.
• Create or add new entries
• Read or view existing entries
• Update or edit existing entries
• Delete existing entries

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Thank You !

• SHAOJIAN ZHU CHIH-HUNG CHO