Spring Cloud 通过 Gateway webflux实现网关异常处理

@Slf4j
@Configuration
public class GlobalExceptionConfig implements ErrorWebExceptionHandler {
    @Autowired
    private ObjectMapper objectMapper;
    /**
     * 全局异常处理
     * @param exchange 交换器(request, response)
     * @param ex 出现异常时的异常对象
     * @return
     */
    @Override
    public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
        Map<String, String> result = new HashMap<>();
        //1.获取响应对象
        ServerHttpResponse response = exchange.getResponse();
        //2. response 是否结束(一般不用，可以用来处理多个异常的场景)
        if(response.isCommitted()) {
            return Mono.error(ex);
        }
        //3.设置响应头类型(JSON)
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        //4.设置响应状态码
        if (ex instanceof IllegalTokenException) {
            //是我们自定义的异常
            response.setStatusCode(HttpStatus.FORBIDDEN);
        } else {
            //不是我们自定义的异常，就通过 "服务器异常" 来处理
            response.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);
        }
        //5.处理统一异常响应
        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);
            }
        }));
    }
}