Question

if I have several DAOs to be injected into a Service that need to work together in a single transaction, how can I do this ?

@Component
public class CallerClass{
@Autowired    
private TransactionClass1 class1;
@Autowired    
private TransactionClass2 class2;

public void saveOperation(){    
    try{
        class1.save();
        class2.save();
    }catch(Exception ex){
    }
}
}

Like above simple codes. However, this code is lack

Answer 1

You would just inject all the DAOs in the same manner as you do normally i.e. setter or constructor using @Inject or @Autowired.

You then annotate your service method as Transactional and invoke the required operations on the multiple DAOs. The transaction will encompass all of the dao calls within it.

@Transactional
public void doStuff() {
  dao1.doStuff();
  dao2.doStuff();
}