Hibernate Configuration

Advertisements


Hibernate requires to know in advance where to find the mapping information that defines how your Java classes relate to the database tables. Hibernate also requires a set of configuration settings related to database and other related parameters. All such information is usually supplied as a standard Java properties file called hibernate.properties, or as an XML file named hibernate.cfg.xml.

I will consider XML formatted file hibernate.cfg.xml to specify required Hibernate properties in my examples. Most of the properties take their default values and it is not required to specify them in the property file unless it is really required. This file is kept in the root directory of your application's classpath.

Hibernate Properties:

Following is the list of important properties you would require to configure for a databases in a standalone situation:

S.N.Properties and Description
1hibernate.dialect
This property makes Hibernate generate the appropriate SQL for the chosen database.
2hibernate.connection.driver_class
The JDBC driver class.
3hibernate.connection.url
The JDBC URL to the database instance.
4hibernate.connection.username
The database username.
5hibernate.connection.password
The database password.
6hibernate.connection.pool_size
Limits the number of connections waiting in the Hibernate database connection pool.
7hibernate.connection.autocommit
Allows autocommit mode to be used for the JDBC connection.

If you are using a database along with an application server and JNDI then you would have to configure the following properties:

S.N.Properties and Description
1hibernate.connection.datasource
The JNDI name defined in the application server context you are using for the application.
2hibernate.jndi.class
The InitialContext class for JNDI.
3hibernate.jndi.<JNDIpropertyname>
Passes any JNDI property you like to the JNDI InitialContext.
4hibernate.jndi.url
Provides the URL for JNDI.
5hibernate.connection.username
The database username.
6hibernate.connection.password
The database password.

Hibernate with MySQL Database:

MySQL is one of the most popular open-source database systems available today. Let us create hibernate.cfg.xml configuration file and place it in the root of your application's classpath. You would have to make sure that you have testdb database available in your MySQL database and you have a user test available to access the database.

The XML configuration file must conform to the Hibernate 3 Configuration DTD, which is available from http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd.

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM 
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
   <session-factory>
   <property name="hibernate.dialect">
      org.hibernate.dialect.MySQLDialect
   </property>
   <property name="hibernate.connection.driver_class">
      com.mysql.jdbc.Driver
   </property>

   <!-- Assume test is the database name -->
   <property name="hibernate.connection.url">
      jdbc:mysql://localhost/test
   </property>
   <property name="hibernate.connection.username">
      root
   </property>
   <property name="hibernate.connection.password">
      root123
   </property>

   <!-- List of XML mapping files -->
   <mapping resource="Employee.hbm.xml"/>

</session-factory>
</hibernate-configuration>

The above configuration file includes <mapping> tags which are related to hibernate-mapping file and we will see in next chapter what exactly is a hibernate mapping file and how and why do we use it. Following is the list of various important databases dialect property type:

DatabaseDialect Property
DB2 org.hibernate.dialect.DB2Dialect
HSQLDB org.hibernate.dialect.HSQLDialect
HypersonicSQLorg.hibernate.dialect.HSQLDialect
Informix org.hibernate.dialect.InformixDialect
Ingres org.hibernate.dialect.IngresDialect
Interbase org.hibernate.dialect.InterbaseDialect
Microsoft SQL Server 2000 org.hibernate.dialect.SQLServerDialect
Microsoft SQL Server 2005org.hibernate.dialect.SQLServer2005Dialect
Microsoft SQL Server 2008org.hibernate.dialect.SQLServer2008Dialect
MySQL org.hibernate.dialect.MySQLDialect
Oracle (any version)org.hibernate.dialect.OracleDialect
Oracle 11gorg.hibernate.dialect.Oracle10gDialect
Oracle 10gorg.hibernate.dialect.Oracle10gDialect
Oracle 9iorg.hibernate.dialect.Oracle9iDialect
PostgreSQL org.hibernate.dialect.PostgreSQLDialect
Progress org.hibernate.dialect.ProgressDialect
SAP DB org.hibernate.dialect.SAPDBDialect
Sybase org.hibernate.dialect.SybaseDialect
Sybase Anywhere org.hibernate.dialect.SybaseAnywhereDialect


Advertisements
Advertisements