java - 在 Spring Boot 中注入(inject) Autowiring 依赖项的问题

Question

我在下面的代码中得到了 @Autowired AccountRepository 的 NoSuchBeanDefinitionException，错误消息是:没有找到类型为 [com.brahalla.PhotoAlbum.dao.AccountRepository] ​​的符合条件的 bean 用于依赖项:预计至少 1有资格作为此依赖项的 Autowiring 候选者的 bean。。我已经将包含存储库的包添加到 @ComponentScan 但由于某种原因它仍然没有看到它。依赖注入(inject)在我项目的其他地方都有效，只是不在这个特定文件中。

package com.brahalla.PhotoAlbum.configuration;

import com.brahalla.PhotoAlbum.dao.AccountRepository;
import com.brahalla.PhotoAlbum.domain.entity.Account;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.authentication.configurers.GlobalAuthenticationConfigurerAdapter;
import org.springframework.security.core.authority.AuthorityUtils;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;

@Configuration
@ComponentScan("com.brahalla.PhotoAlbum.dao")
public class GlobalAuthenticationConfiguration extends GlobalAuthenticationConfigurerAdapter {

  @Autowired
  AccountRepository accountRepository;

  @Override
  public void init(AuthenticationManagerBuilder authenticationManagerBuilder) throws Exception {
    authenticationManagerBuilder.userDetailsService(userDetailsService());
  }

  @Bean
  UserDetailsService userDetailsService() {
    return new UserDetailsService() {

      @Override
      public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        Account account = accountRepository.findByUsername(username);
        if(account != null) {
          return new User(
            account.getUsername(),
            account.getPassword(),
            true, true, true, true,
            AuthorityUtils.createAuthorityList("USER")
          );
        } else {
          throw new UsernameNotFoundException("could not find the user '" + username + "'");
        }
      }

    };
  }

}

这是存储库:

package com.brahalla.PhotoAlbum.dao;

import com.brahalla.PhotoAlbum.domain.entity.Account;

import org.springframework.data.repository.CrudRepository;

public interface AccountRepository extends CrudRepository<Account, Long> {

  public Account findByUsername(String username);

}

以及主要的应用配置:

package com.brahalla.PhotoAlbum.configuration;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ApplicationConfiguration {

    public static void main(String[] args) {
        SpringApplication.run(ApplicationConfiguration.class, args);
    }

}

这是完整的日志和堆栈跟踪:http://pastebin.com/PKvd8rXV

编辑 Here is the git repository ，有问题的代码在分支 develop 中。

Answer 1

带有@controller、@service、@component、@Repository 等注释的类将成为 Autowiring 的候选对象，而其他类则不是。因此请考虑相应地为您的类添加注释以实现正确的 Autowiring 。

@Component --> 任何 Spring 管理的组件的通用构造型

@Repository-->持久层的原型(prototype)

@Service --> 服务层的原型(prototype)

@Controller --> 表示层构造型 (spring-mvc)

下面的代码应该可以工作

 @Repository
 public interface AccountRepository extends CrudRepository<Account, Long> {

  public Account findByUsername(String username);
}