Component types may declare multiple service dependencies through the service tag. Each service tag references a versioned service identifier that the container will supply to the component type on request relative to the declared dependency key.
| Attribute | Required | Description |
|---|---|---|
| type | yes |
The service interface classname that the component is dependent on. |
| version | no |
The service version. If not declared the service dependency shall match any version. |
| optional | no |
A value of 'true' or 'false'. If true, the supply of a dependency is at the discression of the container. If false (the default) a container is required to resolve and supply a service matching the dependency declaration. |
package net.osm;
/**
* Example of a component declaring multiple service dependencies.
*
* @avalon.component version="1.0" name="demo"
*/
public class Demo implements Serviceable
{
...
/**
* Supply of dependent services to this component by
* the container.
* @param manager the service manager
* @avalon.dependency key="home" type="Home" version="1.3"
* @avalon.dependency type="Resource" version="5" optional="true"
*/
public void service( ServiceManager manager )
throws ServiceException
{
m_home = (Home) manager.lookup( "home" );
try
{
m_resource = (Resource) manager.lookup(
Resource.getClass().getName() );
}
catch( ServiceException se )
{
// it's optional
}
}
}
Generated meta-info type descriptor:
<type>
<info>
<version>1.3.0</version>
<name>demo</name>
</info>
<dependencies>
<dependency key="home" type="Home" version="1.3.0"/>
<dependency type="Resource" version="5.0.0" optional="true"/>
</dependencies>
</type>
