How connect multiply databases ( hsqldb, mysql ) with DB setting in separate files - mysql

Question

Basically I want to decide with which of 2 databases project will run.
I have following hibernateContext.xml
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:database.properties</value>
</list>
</property>
</bean>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.user}" />
<property name="password" value="${jdbc.password}" />
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="packagesToScan" value="com.blog.przem.entity" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
And database.properties file
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/pbdb
jdbc.user=root
jdbc.password=
What I'm trying to achieve is to add HSQLDB to my project (for development, testing) but for production I want to have MySQL DB.
I already seen some solutions:
in spring config file Can I use HSQLDB for junit testing cloning a mySQL database
in maven http://www.manydesigns.com/en/portofino/portofino3/tutorials/using-maven-profiles-and-resource-filtering
I wondering what is best approach, but I would like to keep databases settings in separate files.
Should I create database.properties2 file (with HSQL properties) and add propertyConfigurer2? And how to make dataSource bean to know which propertyConfigurer to use (I have feeling that I miss something)?
Maybe it should be done by maven?
What is professional approach to such problem (assuming that project finaly will use MySQL) - application should always use MySQL, and HSQLDB should be used only for running tests classes?

Answer 1

#Ralph answer works nice and as I was told it is good solution for bigger projects, and I have been given another solution how to resolve my problem so many databases can be set for project and tests files without creating additional applicationContext-db.xml ( however I don't know if having separate configuration xml's for tests is better than aproach presented below)
That code for slighty changed my hibernateContext.xml
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.user}" />
<property name="password" value="${jdbc.password}" />
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="packagesToScan" value="com.blog.przem.entity" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${jdbc.hibernate.dialect}</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.cache.use_second_level_cache">false</prop>
<prop key="hibernate.cache.use_query_cache">false</prop>
<prop key="hibernate.hbm2ddl.auto">create-drop</prop>
<prop key="hibernate.format_sql">true</prop>
<prop key="hibernate.connection.autocommit">false</prop>
<prop key="hibernate.transaction.flush_before_completion">true</prop>
</props>
</property>
</bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
PropertyPlaceholderConfigurer was extracted (with removed id="propertyConfigurer") to new file proprtiesContext.xml
(of course was added to hibernateContext.xml)
<beans profile="default">
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:msql_database.properties</value>
</list>
</property>
</bean>
</beans>
<beans profile="testing">
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:hsql_database.properties</value>
</list>
</property>
</bean>
</beans>
Then I modified and added configuration files for both databases:
msql_database.propertie
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/pbdb
jdbc.user=root
jdbc.password=
jdbc.hibernate.dialect=org.hibernate.dialect.MySQLDialect
hsql_database.propertie
jdbc.driver=org.hsqldb.jdbcDriver
jdbc.url=jdbc:hsqldb:mem;shutdown=true
jdbc.user=sa
jdbc.password=
jdbc.hibernate.dialect=org.hibernate.dialect.HSQLDialect
Now if I run (in my case Tomcat) server it using "default" - nothing special - MYSQL database is used
But if I run server with parameter
-Dspring.profiles.active="testing"
It using given profile so my project using HSQLDB HOORAY
Additionally when I add specific profile in test class (just before class name declaration):
#ActiveProfiles("default")
public class UserServiceTest {
Specified database is used for testing

Answer 2

So I would recommend that the server provide the database connection via JNDI.
In additon you need to define the Database Dialact. Therefore I would recommend to use a Server Parameter.
For the test cases I would use an other database configruation file, that does not use jndi, but configure the database like you need it for your tests.
For example in Tomcat: Context.xml (global or better application specific context.xml)
<Resource name="jdbc/yourApp" type="javax.sql.DataSource"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/pbdb?useUnicode=true&characterEncoding=utf8"
auth="Container"
username="" password="geheim"
maxIdle="3" maxActive="15" maxWait="10000" logAbandoned="true" removeAbandoned="true"
removeAbandonedTimeout="60" validationQuery="select 1" />
<Parameter name="yourApp.database.dialect" value="mysql" override="false" />
Spring: applicationContext-db.xml in src\main\resources
<jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/yourApp"/>
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="packagesToScan" value="com.blog.przem.entity" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${yourApp.database.dialect}</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
Now your are able to configure the application on every application server with an different database.
For Database-"integration" Tests based on Spring I would put an test specific applicationContext-db.xml without jndi and dialect property placeholder in src\test\resources (it "overrides" the normal one for the tests).
#See this answer for some additional information Spring Configuration - it describes an other way of how to name applicationContext-db.xml for the tests.