SpringBoot集成 Spring Security出现UserNotFoundException 不抛出问题

最近项目中在使用Spring Security的token；在做退出和验证时，出现UserNotFoundException 不抛出问题；

当用户不存在时，只会抛出 BadCredentialsException，而不是 UsernameNotFoundException；

首先debug断点跟踪

进入该断点行中，根据断点信息已知 providers 一共只有1个，当前的 providers 是 DaoAuthenticationProvider

代码1：

protected final UserDetails retrieveUser(String username,
			UsernamePasswordAuthenticationToken authentication)
			throws AuthenticationException {
		prepareTimingAttackProtection();
		try {
			UserDetails loadedUser = this.getUserDetailsService().loadUserByUsername(username);
			if (loadedUser == null) {
				throw new InternalAuthenticationServiceException(
						"UserDetailsService returned null, which is an interface contract violation");
			}
			return loadedUser;
		}
		catch (UsernameNotFoundException ex) {
            // 用户不存进到这里
			mitigateAgainstTimingAttack(authentication);
			throw ex;
		}
		catch (InternalAuthenticationServiceException ex) {
			throw ex;
		}
		catch (Exception ex) {
			throw new InternalAuthenticationServiceException(ex.getMessage(), ex);
		}
	}

被抛到了 DaoAuthenticationProvider 的父类 AbstractUserDetailsAuthenticationProvider 的 authenticate() 方法中。如下所示，在 catch 到 UsernameNotFoundException 后，有个关键的 hideUserNotFoundExceptions 变量。当 hideUserNotFoundExceptions 为true 时，在这个地方被重新包装成了 BadCredentialsException 抛出去。

代码2：

public Authentication authenticate(Authentication authentication)
			throws AuthenticationException {
		Assert.isInstanceOf(UsernamePasswordAuthenticationToken.class, authentication,
				() -> messages.getMessage(
						"AbstractUserDetailsAuthenticationProvider.onlySupports",
						"Only UsernamePasswordAuthenticationToken is supported"));

		// Determine username
		String username = (authentication.getPrincipal() == null) ? "NONE_PROVIDED"
				: authentication.getName();

		boolean cacheWasUsed = true;
		UserDetails user = this.userCache.getUserFromCache(username);

		if (user == null) {
			cacheWasUsed = false;

			try {
				user = retrieveUser(username,
						(UsernamePasswordAuthenticationToken) authentication);
			}
			catch (UsernameNotFoundException notFound) {
				logger.debug("User '" + username + "' not found");
                //  再找不到user的时候报错进到这里，hideUserNotFoundExceptions默认为true；导致无法报用户不存在错误
				if (hideUserNotFoundExceptions) {
					throw new BadCredentialsException(messages.getMessage(
							"AbstractUserDetailsAuthenticationProvider.badCredentials",
							"Bad credentials"));
				}
				else {
					throw notFound;
				}
			}

			Assert.notNull(user,
					"retrieveUser returned null - a violation of the interface contract");
		}

		try {
			preAuthenticationChecks.check(user);
			additionalAuthenticationChecks(user,
					(UsernamePasswordAuthenticationToken) authentication);
		}
		catch (AuthenticationException exception) {
			if (cacheWasUsed) {
				// There was a problem, so try again after checking
				// we're using latest data (i.e. not from the cache)
				cacheWasUsed = false;
				user = retrieveUser(username,
						(UsernamePasswordAuthenticationToken) authentication);
				preAuthenticationChecks.check(user);
				additionalAuthenticationChecks(user,
						(UsernamePasswordAuthenticationToken) authentication);
			}
			else {
				throw exception;
			}
		}

		postAuthenticationChecks.check(user);

		if (!cacheWasUsed) {
			this.userCache.putUserInCache(user);
		}

		Object principalToReturn = user;

		if (forcePrincipalAsString) {
			principalToReturn = user.getUsername();
		}

		return createSuccessAuthentication(principalToReturn, authentication, user);
	}

解决办法：

将AbstractUserDetailsAuthenticationProvider的变量hideUserNotFoundExceptions修改为false；

@Bean
public DaoAuthenticationProvider authenticationProvider() {
    DaoAuthenticationProvider provider = new DaoAuthenticationProvider();
    provider.setHideUserNotFoundExceptions(false);
    provider.setUserDetailsService(userDetailsService);
    provider.setPasswordEncoder(passwordEncoder());
    return provider;
}