如何制作没有类型的JpaRepository，或者只有查询的jpa repo？

import org.springframework.data.jpa.repository.JpaRepository;

public interface CustomRepository extends JpaRepository<Object, Long> {
    
}

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;

public interface CustomRepository extends JpaRepository<Object, Long> {
    
    @Query("SELECT u FROM User u WHERE u.username = ?1")
    User findByUsername(String username);
    
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {
    
    private final CustomRepository customRepository;
    
    @Autowired
    public UserService(CustomRepository customRepository) {
        this.customRepository = customRepository;
    }
    
    public User getUserByUsername(String username) {
        return customRepository.findByUsername(username);
    }
    
}