Sometimes we may need to enable some Beans based on some configuration. For this purpose we can use spring profiles. By using spring bean we can say if a particular profile is active then enable a Bean.
This concept will be more clear with an example. Assume we have 2 beans and we want to enable them as follows
| Bean Class Name | Profile Details |
| DevUserRetrievalService | If profile is development, then add this bean to application context |
| ProdUserRetrievalService | If profile is production, then add this bean to application context |
In our application there is a UserManagementService that will print User details.
@Service
public class UserManagementService {
@Autowired
private UserRetrievalService userRetrievalService;
public void printUserDetails(int userId){
UserDetails userDetails = userRetrievalService.getUserDetails(userId);
System.out.println("user's name = "+userDetails.getName());
}
}
In the above as you can see UserRetrievalService service is autowired. Code of UserRetrievalService is given below
public interface UserRetrievalService {
public UserDetails getUserDetails(int userId);
}
This means someone need to implement UserRetrievalService interface and that bean should be available inside application context. Then only spring will be able to autowire UserRetrievalService’s implementation bean.
Assume we have two beans that implement UserRetrievalService interface. DevUserRetrievalService and ProdUserRetrievalService. In development area we need enable DevUserRetrievalService and in production we need to enable ProdUserRetrievalService. This can be done with the help of profiles.
@Profile("development") //This line says that this beans should be enabled if the profile is development
@Service
public class DevUserRetrievalService implements UserRetrievalService {
@Override
public UserDetails getUserDetails(int userId) {
//retreve user details from a file and return
UserDetails userDetails = getUserDetailsFromFile(userId);
return userDetails;
}
private UserDetails getUserDetailsFromFile(int userId) {
//For simplicity of the example, return hard coded user details;
UserDetails userDetails = new UserDetails();
userDetails.setName("Development user");
userDetails.setAge(42);
userDetails.setAddress("UK");
return userDetails;
}
}
@Profile("production") //This line says that this beans should be enabled if the profile is production
@Service
public class ProdUserRetrievalService implements UserRetrievalService {
@Override
public UserDetails getUserDetails(int userId) {
//retreve user details from production database and return
UserDetails userDetails = getUserDetailsFromDb(userId);
return userDetails;
}
private UserDetails getUserDetailsFromDb(int userId) {
//For simplicity of the example, return hard coded user details;
UserDetails userDetails = new UserDetails();
userDetails.setName("Production user");
userDetails.setAge(41);
userDetails.setAddress("Japan");
return userDetails;
}
}
Now we created multiple implementations of UserRetrievalService. We also specified to enable DevUserRetrievalService if profile is development and enable ProdUserRetrievalService if profile is production.
Now before running the application we should tell which profile we need to activate. There are multiple ways to achieve this. One way is to specify this in application.properties as shown below
spring.profiles.active=development After starting our application if you call printUserDetails method in UserManagementService you will get below output
user's name = Development user