[Java] 익명 클래스에서 람다 함수로 변경

public void anomymousClass() {
  final String hello = FUNLEE.callHello(new Hello() -> {
    @Override
    public String hello(String name) {
      return "Hello, " + name;
    }
  });
  
  System.out.println(hello);
}

public void anomymousClass() {
  final String hello = FUNLEE.callHello((String name) -> {
    return "Hello, " + name;
  });

  System.out.println(hello);
}

public void anomymousClass() {
  final String hello = FUNLEE.callHello(name -> {
    return "Hello, " + name;
  });

  System.out.println(hello);
}

public void anomymousClass() {
  final String hello = FUNLEE.callHello(name -> "Hello, " + name);

  System.out.println(hello);
}

@RequiredArgsConstructor
@Service
public class FunleeService {
  private final FunleeRepository repo;

  public Funlee findById(long id) {
    return repo.findById(id).orElseGet(Funlee::new);
  }
}

// Optional.class
public T orElseGet(Supplier<? extends T> supplier) {
  return this.value != null ? this.value : supplier.get();
}

// Supplier.java
@FunctionalInterface
public interface Supplier<T> {
  T get();
}

public Funlee findById(long id) {
  return repo.findById(id).orElseGet(new Supplier<Funlee>() {
    @Override
    public Funlee get() {
      return new Funlee();
    }
  }
}