關於解決Application failed to start with classpath；SpringBoot的service無法注入bean的問題

和網上大多數不同，我是日志文件的兩個包倒錯了，應該是
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UserService {
    private static final Logger logger = LoggerFactory.getLogger(UserService.class);