Spring Security实战-认证核心验证器验证逻辑AuthenticationProviderManagerAuthenticationProvider

public interface Authentication extends Principal, Serializable {
    // 权限集合，可使用AuthorityUtils.commaSeparatedStringToAuthorityList("admin,ROLE_ADMIN")返回字符串权限集合
    Collection<? extends GrantedAuthority> getAuthorities();
    // 用户名密码认证时可以理解为密码
    Object getCredentials();
    // 认证请求包含的一些附加信息(如 IP 地址,数字证书号)
    Object getDetails();
    // 用户名密码认证时可理解为用户名
    Object getPrincipal();
    // 是否被认证
    boolean isAuthenticated();
    // 设置是否能被认证
    void setAuthenticated(boolean isAuthenticated) throws IllegalArgumentException;

public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        // 1.获取当前的Authentication的认证类型
        Class<? extends Authentication> toTest = authentication.getClass();
        AuthenticationException lastException = null;
        Authentication result = null;
        boolean debug = logger.isDebugEnabled();
        
        // 2.遍历所有的 providers 使用 supports 方法判断该 provider 是否支持当前的认证类型
        for (AuthenticationProvider provider : getProviders()) {
            if (!provider.supports(toTest)) {
                continue;
            }

            if (debug) {
                logger.debug("Authentication attempt using "
                        + provider.getClass().getName());
            }

            try {
                // 3.若支持,调用 provider#authenticat 认证
                result = provider.authenticate(authentication);

                if (result != null) {
                    // 4.认证通过则重新生成 Authentication 对应的 Token
                    copyDetails(authentication, result);
                    break;
                }
            }
            catch (AccountStatusException e) {
                prepareException(e, authentication);
                // SEC-546: Avoid polling additional providers if auth failure is due to
                // invalid account status
                throw e;
            }
            catch (InternalAuthenticationServiceException e) {
                prepareException(e, authentication);
                throw e;
            }
            catch (AuthenticationException e) {
                lastException = e;
            }
        }

        if (result == null && parent != null) {
            // Allow the parent to try.
            try {
                // 5.如果 1 没有验证通过，则使用父类 AuthenticationManager 进行验证
                result = parent.authenticate(authentication);
            }
            catch (ProviderNotFoundException e) {
                // ignore as we will throw below if no other exception occurred prior to
                // calling parent and the parent
                // may throw ProviderNotFound even though a provider in the child already
                // handled the request
            }
            catch (AuthenticationException e) {
                lastException = e;
            }
        }
        // 6. 是否查出敏感信息
        if (result != null) {
            if (eraseCredentialsAfterAuthentication
                    && (result instanceof CredentialsContainer)) {
                // Authentication is complete. Remove credentials and other secret data
                // from authentication
                ((CredentialsContainer) result).eraseCredentials();
            }

            eventPublisher.publishAuthenticationSuccess(result);
            return result;
        }

        // Parent was null, or didn't authenticate (or throw an exception).

        if (lastException == null) {
            lastException = new ProviderNotFoundException(messages.getMessage(
                    "ProviderManager.providerNotFound",
                    new Object[] { toTest.getName() },
                    "No AuthenticationProvider found for {0}"));
        }

        prepareException(lastException, authentication);

        throw lastException;
    }

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 {
                #1.获取用户信息由子类实现即DaoAuthenticationProvider
                user = retrieveUser(username,
                        (UsernamePasswordAuthenticationToken) authentication);
            }
            catch (UsernameNotFoundException notFound) {
                logger.debug("User '" + username + "' not found");

                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 {
            #2.前检查由DefaultPreAuthenticationChecks类实现（主要判断当前用户是否锁定，过期，冻结User接口）
            preAuthenticationChecks.check(user);
            #3.子类实现
            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;
            }
        }
        #4.检测用户密码是否过期对应#2 的User接口
        postAuthenticationChecks.check(user);

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

        Object principalToReturn = user;

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

        return createSuccessAuthentication(principalToReturn, authentication, user);
    }