Penjelasan @Autowired dapat disimak di link berikut.
Contoh code dengan @Autowired
@Controller // Defines that this class is a spring bean
@RequestMapping("/users")
public class SomeController {
// Tells the application context to inject an instance of UserService here
@Autowired
private UserService userService;
@RequestMapping("/login")
public void login(@RequestParam("username") String username,
@RequestParam("password") String password) {
// The UserServiceImpl is already injected and you can use it
userService.login(username, password);
}
}
Contoh code tanpa @Autowired
@Controller // Defines that this class is a spring bean
@RequestMapping("/users")
public class SomeController {
private UserService userService;
public SomeController(UserService userService) {
this.userService = userService;
}
@RequestMapping("/login")
public void login(@RequestParam("username") String username,
@RequestParam("password") String password) {
// The UserServiceImpl is already injected and you can use it
userService.login(username, password);
}
}
Override
Penjelasan @Override dapat disimak pada link berikut.
Contoh code penggunaan @Override pada subclass.
Animal.java
public class Animal {
public void makeSound() {
System.out.println("The animal makes a sound");
}
}
Dog.java
public class Dog extends Animal {
@Override
public void makeSound() {
System.out.println("The dog barks");
}
}
Contoh code penggunaan @Override pada class yang mengimplementasikan method yang sama pada suatu interface.
FooService.java
public interface FooService {
void doSomething();
}
FooServiceImpl.java
@Service
public class FooServiceImpl implements FooService {
@Override
public void doSomething() {
// ...
}
}
Qualifier
Penjelasan @Qualifier dapat simak pada link berikut.
Contoh code penggunaan @Qualifier.
FooFormatter.java
@Component("fooFormatter")
public class FooFormatter implements Formatter {
public String format() {
return "foo";
}
}
BarFormatter.java
@Component("barFormatter")
public class BarFormatter implements Formatter {
public String format() {
return "bar";
}
}
FooService.java
@Component
public class FooService {
@Autowired
@Qualifier("fooFormatter")
private Formatter formatter;
}
Package java.util.List
ListExample.java
import java.util.ArrayList;
import java.util.List;
public class ListExample {
public static void main(String[] args) {
List<String> list = new ArrayList<>();
list.add("apple");
list.add("banana");
list.add("cherry");
System.out.println(list);
}
}
