【SpringCloud】Gateway 配置全局过滤器获取请求参数和响应值

实现 Ordered 接口 getOrder() 方法，数值越小越靠前执行，记得这一点就 OK 了。

获取请求参数 RequestBody

@Component
@Slf4j
@AllArgsConstructor
public class HttpRequestFilter implements GlobalFilter, Ordered {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request = exchange.getRequest();

        String method = request.getMethodValue();
        String contentType = request.getHeaders().getFirst("Content-Type");
        if ("POST".equals(method)) {return DataBufferUtils.join(exchange.getRequest().getBody())
                    .flatMap(dataBuffer -> {byte[] bytes = new byte[dataBuffer.readableByteCount()];
                        dataBuffer.read(bytes);
                        try {String bodyString = new String(bytes, "utf-8");
                            log.info(bodyString);// 打印请求参数
                            exchange.getAttributes().put("POST_BODY", bodyString);
                        } catch (UnsupportedEncodingException e) {e.printStackTrace();
                        }
                        DataBufferUtils.release(dataBuffer);
                        Flux<DataBuffer> cachedFlux = Flux.defer(() -> {DataBuffer buffer = exchange.getResponse().bufferFactory()
                                    .wrap(bytes);
                            return Mono.just(buffer);
                        });

                        ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {
                            @Override
                            public Flux<DataBuffer> getBody() {return cachedFlux;}
                        };
                        return chain.filter(exchange.mutate().request(mutatedRequest)
                                .build());
                    });
        }
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {return -200;}
}

获取请求响应值 ResponseBody

POSTMAN 工具请求里的 gzip 压缩头导致获取响应值一直乱码，解决 gzip 压缩后响应值获取

@Slf4j
@Component
public class HttpResponseFilter implements GlobalFilter, Ordered {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request = exchange.getRequest();
        String path = request.getPath().toString();
        ServerHttpResponse originalResponse = exchange.getResponse();
        System.out.println(originalResponse.isCommitted());
        DataBufferFactory bufferFactory = originalResponse.bufferFactory();

        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
            @Override
            public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {if (body instanceof Flux) {Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;
                    return super.writeWith(fluxBody.buffer().map(dataBuffer -> {DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
                        DataBuffer join = dataBufferFactory.join(dataBuffer);
                        byte[] content = new byte[join.readableByteCount()];
                        join.read(content);
                        // 释放掉内存
                        DataBufferUtils.release(join);
                        String s = new String(content, StandardCharsets.UTF_8);

                        List<String> strings = exchange.getResponse().getHeaders().get(HttpHeaders.CONTENT_ENCODING);
                        if (!CollectionUtils.isEmpty(strings) && strings.contains("gzip")) {
                            GZIPInputStream gzipInputStream = null;
                            try {gzipInputStream = new GZIPInputStream(new ByteArrayInputStream(content), content.length);
                                StringWriter writer = new StringWriter();
                                IOUtils.copy(gzipInputStream, writer, "UTF-8");
                                s = writer.toString();} catch (IOException e) {log.error("====Gzip IO error", e);
                            } finally {if (gzipInputStream != null) {
                                    try {gzipInputStream.close();
                                    } catch (IOException e) {log.error("===Gzip IO close error", e);
                                    }
                                }
                            }
                        } else {s = new String(content, StandardCharsets.UTF_8);
                        }
                        log.info("bodyString: {}", s);// 打印请求响应值
                        return bufferFactory.wrap(content);
                    }));
                }
                return super.writeWith(body);
            }
        };
        return chain.filter(exchange.mutate().response(decoratedResponse).build());
    }

    @Override
    public int getOrder() {return -200;}
}

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