@Slf4j
@Configuration
public class GlobalExceptionConfig implements ErrorWebExceptionHandler {
    @Autowired
    private ObjectMapper objectMapper;
    /**
     * 全局異常處理
     * @param exchange 交換器(request, response)
     * @param ex 出現(xiàn)異常時的異常對象
     * @return
     */
    @Override
    public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
        Map<String, String> result = new HashMap<>();
        //1.獲取響應(yīng)對象
        ServerHttpResponse response = exchange.getResponse();
        //2. response 是否結(jié)束(一般不用，可以用來處理多個異常的場景)
        if(response.isCommitted()) {
            return Mono.error(ex);
        }
        //3.設(shè)置響應(yīng)頭類型(JSON)
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        //4.設(shè)置響應(yīng)狀態(tài)碼
        if (ex instanceof IllegalTokenException) {
            //是我們自定義的異常
            response.setStatusCode(HttpStatus.FORBIDDEN);
        } else {
            //不是我們自定義的異常，就通過 "服務(wù)器異常" 來處理
            response.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);
        }
        //5.處理統(tǒng)一異常響應(yīng)
        return response.writeWith(Mono.fromSupplier(() -> {
            DataBufferFactory bufferFactory = response.bufferFactory();
            result.put("msg", ex.getMessage());
            try {
                return bufferFactory.wrap(objectMapper.writeValueAsBytes(result));
            } catch (JsonProcessingException e) {
                throw new RuntimeException(e);
            }
        }));
    }
}