JCR Configuration persister
Idea
JCR Repository Service uses
org.exoplatform.services.jcr.config.RepositoryServiceConfiguration component to read its configuration.
<component>
<key>org.exoplatform.services.jcr.config.RepositoryServiceConfiguration</key>
<type>org.exoplatform.services.jcr.impl.config.RepositoryServiceConfigurationImpl</type>
<init-params>
<value-param>
<name>conf-path</name>
<description>JCR configuration file</description>
<value>/conf/standalone/exo-jcr-config.xml</value>
</value-param>
</init-params>
</component>
In the example Repository Service will read the configuration from the file
/conf/standalone/exo-jcr-config.xml.
But in some cases it's required to change the configuration on the fly. And know that the new one will be used. Additionally we wish not to modify the original file.
In this case we have to use the configuration persister feature which allows to store the configuration in different locations.
Usage
On startup
RepositoryServiceConfiguration component checks if a configuration persister was configured.
In that case it uses the provided
ConfigurationPersister implementation class to instantiate the persister object.
Configuration with persister:
<component>
<key>org.exoplatform.services.jcr.config.RepositoryServiceConfiguration</key>
<type>org.exoplatform.services.jcr.impl.config.RepositoryServiceConfigurationImpl</type>
<init-params>
<value-param>
<name>conf-path</name>
<description>JCR configuration file</description>
<value>/conf/standalone/exo-jcr-config.xml</value>
</value-param>
<properties-param>
<name>working-conf</name>
<description>working-conf</description>
<property name="source-name" value="jdbcjcr" />
<property name="dialect" value="mysql" />
<property name="persister-class-name" value="org.exoplatform.services.jcr.impl.config.JDBCConfigurationPersister" />
</properties-param>
</init-params>
</component>
where:
source-name - JNDI source name configured in
InitialContextInitializer component. (
sourceName prior v.1.9.) Find more in
database configuration.
dialect - SQL dialect which will be used with database from
source-name. Find more in
database configuration.
persister-class-name - class name of
ConfigurationPersister interface implementation. (
persisterClassName prior v.1.9.)
ConfigurationPersister interface:
/**
* Init persister.
* Used by RepositoryServiceConfiguration on init.
* @return - config data stream
*/
void init(PropertiesParam params) throws RepositoryConfigurationException;
/**
* Read config data.
* @return - config data stream
*/
InputStream read() throws RepositoryConfigurationException;
/**
* Create table, write data.
* @param confData - config data stream
*/
void write(InputStream confData) throws RepositoryConfigurationException;
/**
* Tell if the config exists.
* @return - flag
*/
boolean hasConfig() throws RepositoryConfigurationException;
JCR Core implementation contains a persister which stores the repository configuration in the relational database using JDBC calls -
org.exoplatform.services.jcr.impl.config.JDBCConfigurationPersister.
The implementation will crate and use table
JCR_CONFIG in the provided database.
But the developer can implement his own persister for his particular usecase.
