【小技巧】spring security oauth2 令牌实现多终端登录状态同步

	@Transactional
	public OAuth2AccessToken createAccessToken(OAuth2Authentication authentication) throws AuthenticationException {
        // 1. 判断是否存在Token
		OAuth2AccessToken existingAccessToken = tokenStore.getAccessToken(authentication);
		OAuth2RefreshToken refreshToken = null;
		if (existingAccessToken != null) {
			if (existingAccessToken.isExpired()) {
				if (existingAccessToken.getRefreshToken() != null) {
					refreshToken = existingAccessToken.getRefreshToken();
					tokenStore.removeRefreshToken(refreshToken);
				}
				tokenStore.removeAccessToken(existingAccessToken);
			}
			else {
				tokenStore.storeAccessToken(existingAccessToken, authentication);
				return existingAccessToken;
			}
		}
        
        // 2. 创建新token
		OAuth2AccessToken accessToken = createAccessToken(authentication, refreshToken);
		tokenStore.storeAccessToken(accessToken, authentication);
		// In case it was modified
		refreshToken = accessToken.getRefreshToken();
		if (refreshToken != null) {
			tokenStore.storeRefreshToken(refreshToken, authentication);
		}
		return accessToken;

	}

OAuth2AccessToken existingAccessToken = tokenStore.getAccessToken(authentication);


@Override
public OAuth2AccessToken getAccessToken(OAuth2Authentication authentication) {
   // 构造 默认保存的
	String key = authenticationKeyGenerator.extractKey(authentication);
	// key 加上前缀
	byte[] serializedKey = serializeKey(AUTH_TO_ACCESS + key);
	byte[] bytes = null;
	RedisConnection conn = getConnection();
	try {
		bytes = conn.get(serializedKey);
	} finally {
		conn.close();
	}
	OAuth2AccessToken accessToken = deserializeAccessToken(bytes);
	if (accessToken != null) {
		OAuth2Authentication storedAuthentication = readAuthentication(accessToken.getValue());
		if ((storedAuthentication == null || !key.equals(authenticationKeyGenerator.extractKey(storedAuthentication)))) {
			storeAccessToken(accessToken, authentication);
		}

	}
	return accessToken;
}

public String extractKey(OAuth2Authentication authentication) {
	Map<String, String> values = new LinkedHashMap<String, String>();
	OAuth2Request authorizationRequest = authentication.getOAuth2Request();
	if (!authentication.isClientOnly()) {
		values.put(USERNAME, authentication.getName());
	}
	values.put(CLIENT_ID, authorizationRequest.getClientId());
	if (authorizationRequest.getScope() != null) {
		values.put(SCOPE, OAuth2Utils.formatParameterList(new TreeSet<String>(authorizationRequest.getScope())));
	}
	return generateKey(values);
}

public class PigxAuthenticationKeyGenerator extends DefaultAuthenticationKeyGenerator {

	private static final String SCOPE = "scope";

	private static final String USERNAME = "username";
	
	@Override
	public String extractKey(OAuth2Authentication authentication) {
		Map<String, String> values = new LinkedHashMap<String, String>();
		OAuth2Request authorizationRequest = authentication.getOAuth2Request();
		if (!authentication.isClientOnly()) {
			values.put(USERNAME, authentication.getName());
		}
		if (authorizationRequest.getScope() != null) {
			values.put(SCOPE, OAuth2Utils.formatParameterList(new TreeSet<String>(authorizationRequest.getScope())));
		}
		
		// 如果是多租户系统，这里要区分租户ID 条件
		return generateKey(values);
	}
}

	@Bean
	public TokenStore tokenStore() {
		RedisTokenStore tokenStore = new RedisTokenStore(redisConnectionFactory);
		tokenStore.setPrefix(SecurityConstants.PIGX_PREFIX + SecurityConstants.OAUTH_PREFIX);
		tokenStore.setAuthenticationKeyGenerator(new PigxAuthenticationKeyGenerator());
		return tokenStore;
	}