The FactoryBean can be used to programmatically create objects which might require complex instantiation logic.
However, it seems that the beans created by the FactoryBean
doesn't become spring managed. Is this interpretation correct? If so, are there any nice workarounds? A short code sample is included to illustrate my problem.
ApplicationContext:
<bean id="searcher" class="some.package.SearcherFactory" />
<bean id="service" class="some.package.Service" />
Factory implementation:
public class SearcherFactory implements FactoryBean<Searcher> {
@Override
public Searcher getObject() throws Exception {
return new Searcher(); // not so complex after all ;)
}
@Override
public Class<Searcher> getObjectType() {
return Searcher.class;
}
....
}
Class created by the factory:
public class Searcher() {
private Service service;
@Autowired
public void setService(Service service) {
// never invoked
this.service=service;
}
}
Here is an abstract FactoryBean
implementation that does autowiring for you:
public abstract class AbstractAutowiringFactoryBean<T> extends
AbstractFactoryBean<T> implements ApplicationContextAware{
private ApplicationContext applicationContext;
@Override
public void setApplicationContext(
final ApplicationContext applicationContext){
this.applicationContext = applicationContext;
}
@Override
protected final T createInstance() throws Exception{
final T instance = doCreateInstance();
if(instance != null){
applicationContext
.getAutowireCapableBeanFactory()
.autowireBean(instance);
}
return instance;
}
/**
* Create the bean instance.
*
* @see #createInstance()
*/
protected abstract T doCreateInstance();
}
Extend it, implement the getObjectType()
and doCreateInstance()
methods and you're up and running with autowiring.
Note: BeanPostProcessors are not applied, that would require additional code.