|
Hibernate 3 Tutorial
Previous
Next
Step1>Getting Ready
ORM is a way to map java objects for automatic persistence of objects into a database.
The issues to be resolved by the ORM are: how mappings to tables are defined , how can
we translate the inheritance in Java to database tables and how the queries can be defined
in an object oriented way. The ORM tools are designed to increase productivity, make maintenance easier
and allow for performance optimzations.
Hibernate is the leading ORM framework/tool. It provides Java based veiw of persistent data. It
works with POJO(Plain Old Java Objects) to avoid any overheads. It supports object oriented concepts of
encapsulation, inheritance and polymorphism. It allows for writing SQL queries to be written externally
in the files and maintained separately, adding flexibility. Queries are written in Object oriented way
using objects instead of tables, using HQL(Hibernate Query Language).
Before you get into developing an example application download the Hibernate using link on left.
Also you can
download the oracle xpress edition free by clicking on this text. The exact setup used in the tutorial is
like this:
- Oracle database express edition: version 10g XE
- Hibernate Core: version 3.3.2
- Hibernate Annotations: version 3.4.0
- IDE used: Eclipse Java EE IDE for web developers(I suppose Any version is fine)
Tip Be very careful, in setting your class path. The incompatibilities in the
jar files can make your life miserable, in todays open source based systems.
Especially be
careful about the SLF4J files. SLF4J or Simple Logging Facade for Java is used by Hibernate
libraries to do logging through Log4j tool. Where we have choices there we have to pay price
sometimes. The combination and order of jar files is important. If you follow the order and
include the following jars you should be fine other wise the inter-dependency of the jar files
can be tricky. You do not need to have the ojdbc14.jar file in your class path if you are not
using Oracle database. This jar contains the drivers for Oracle DB, you can replace this one
with the jar file for the database you use.
Tip Try to download a jar file from internet if you cannot find it in the Hibernate download.
Keep the version number in mind when downloading.
List of jar files needed for Hibernate development:
hibernate-distribution-3.3.2.GA/hibernate3.jar
hibernate-distribution-3.3.2.GA/lib/required/antlr-2.7.6.jar
hibernate-distribution-3.3.2.GA/lib/required/dom4j-1.6.1.jar
hibernate-distribution-3.3.2.GA/lib/required/javassist-3.9.0.GA.jar
hibernate-distribution-3.3.2.GA/lib/required/jta-1.1.jar
hibernate-annotations-3.4.0.GA/lib/dom4j.jar
hibernate-annotations-3.4.0.GA/lib/ejb3-persistence.jar
hibernate-annotations-3.4.0.GA/lib/hibernate-commons-annotations.jar
hibernate-annotations-3.4.0.GA/lib/hibernate-core.jar
hibernate-annotations-3.4.0.GA/hibernate-annotations.jar
ojdbc14.jar
slf4j-log4j12-1.4.2.jar
slf4j-api-1.5.8.jar
log4j-1.2.14.jar
commons-collections-3.1.jar
Hibernate Core is the core framework which handles all the base fucntionality provided by Hibernate ORM.
Additionally the Hibernate Annotations component adds up the annotations(Java Annotations) based
functionality into the Hibernate3.x version. The annotations component adds Java 5 and Hiibernate specific
annotations to be used in Hibernate3 version. Regarding the last item, I guess everyone knows what IDE and Eclipse is, that is the
Integratred Developement Environment which enables faster software development.
This tutorial will be a fast one, to let you start up Hibernate quickly, so that you can learn the details later.
Previous
Next
|