Dependency Injection into your Singleton
- by Langali
I have a singleton that has a spring injected Dao (simplified below):
public class MyService<T> implements Service<T> {
private final Map<String, T> objects;
private static MyService instance;
MyDao myDao;
public void set MyDao(MyDao myDao) {
this. myDao = myDao;
}
private MyService() {
this.objects = Collections.synchronizedMap(new HashMap<String, T>());
// start a background thread that runs for ever
}
public static synchronized MyService getInstance() {
if(instance == null) {
instance = new MyService();
}
return instance;
}
public void doSomething() {
myDao.persist(objects);
}
}
My spring config will probably look like this:
<bean id="service" class="MyService" factory-method="getInstance"/>
But this will instantiate the MyService during startup.
Is there a programmatic way to do a dependency injection of MyDao into MyService, but not have spring manage the MyService?
Basically I want to be able to do this from my code:
MyService.getInstance().doSomething();
while having spring inject the MyDao for me.
