循环依赖 - Githubissues

Snailclimb / spring-security-jwt-guide

从零入门！Spring Security With JWT（含权限验证）后端部分代码。

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最近在学习这个项目中的Spring Security，用其中的代码做了一个自己的项目，在线下用mvn package和java -jar都运行正常，使用DevOps部署到线上出现了循环依赖的异常。（为了使idea生成下面的图，加了几处@Autowired注解）

要生成userController，就需要通过自动装配方式使用userService
```
public class UserController {
private final UserService userService;
```

其中userService需要bCryptPasswordEncoder，也是通过@Autowired方式装配

public class UserService {
@Autowired
private final BCryptPasswordEncoder bCryptPasswordEncoder;

bCryptPasswordEncoder从securityConfig中由注解@Bean制造出

public class SecurityConfig extends WebSecurityConfigurerAdapter {
  @Bean
  public BCryptPasswordEncoder bCryptPasswordEncoder() {
      return new BCryptPasswordEncoder();
  }

bCrypt

在此之前，securityConfig需要得到userDetailsServiceImpl

public class SecurityConfig extends WebSecurityConfigurerAdapter {
@Autowired
UserDetailsServiceImpl userDetailsServiceImpl;

userDetailsServiceImpl又需要使用userService来调用它的find方法

@Service
public class UserDetailsServiceImpl implements UserDetailsService {

   private final UserService userService;

   @Autowired
   public UserDetailsServiceImpl(UserService userService) {
       this.userService = userService;
   }

   @Override
   public UserDetails loadUserByUsername(String name) {
       User user = userService.find(name);
       return new JwtUser(user);
   }

 }

UserDetailsServiceImpl

但此时的userService还没有制造好……于是有了循环依赖异常org.springframework.beans.factory.UnsatisfiedDependencyException --> UnsatisfiedDependencyException --> ... --> beans.factory.BeanCurrentlyInCreationException

通过改写loadUserByUsername的方式，去除了UserDetailsServiceImpl对UserService的依赖，临时性地解决了这个异常。

@Service public class UserDetailsServiceImpl implements UserDetailsService { private final UserService userService; @Autowired public UserDetailsServiceImpl(UserService userService) { this.userService = userService; } @Override public UserDetails loadUserByUsername(String name) { User user = userService.find(name); return new JwtUser(user); } }

Snailclimb / spring-security-jwt-guide

循环依赖 #22