SpringCloudGateway笔记(6)-请求体不全

阳光穿透心脏的1/2处 2021-12-14 21:29 1435阅读 0赞

实际使用遇到的问题 – 在filter里面获取RequestBody不完整以及LEAK MEMORY的问题

#### 第一种获取方式 ####

在网上找到的最常见的一种获取RequestBody的方式是

private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest){
            //获取请求体
            Flux<DataBuffer> body = serverHttpRequest.getBody();
            StringBuilder sb = new StringBuilder();
    
            body.subscribe(buffer -> {
                byte[] bytes = new byte[buffer.readableByteCount()];
                buffer.read(bytes);
                DataBufferUtils.release(buffer);
                String bodyString = new String(bytes, StandardCharsets.UTF_8);
                sb.append(bodyString);
            });
            return sb.toString();
        }

这种方式会导致获取到的body不完整

在新版本SpringBoot 2.1.5.RELEAS +SpringCloud Greenwich.SR1中

获取不到RequestBody

完整的测试代码如下

@Slf4j
    @Component
    public class RequestBodyFilter implements GlobalFilter, Ordered {
        @Override
        public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
            if (HttpMethod.POST.equals(exchange.getRequest().getMethod()) && null != exchange.getRequest().getHeaders().getContentType()
                    && exchange.getRequest().getHeaders().getContentType().includes(MediaType.APPLICATION_JSON)
                    && !exchange.getRequest().getHeaders().getContentType().includes(MediaType.MULTIPART_FORM_DATA)) {
    
                String requestbody = resolveBodyFromRequest(exchange.getRequest());
                log.info("requestbody: \n {}", requestbody);
                return chain.filter(exchange.mutate().request(generateNewRequest(exchange.getRequest(), requestbody)).build());
            }
            return chain.filter(exchange);
        }
    
        private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest) {
            //获取请求体
            Flux<DataBuffer> body = serverHttpRequest.getBody();
            StringBuilder sb = new StringBuilder();
    
            body.subscribe(buffer -> {
                byte[] bytes = new byte[buffer.readableByteCount()];
                buffer.read(bytes);
                String bodyString = new String(bytes, StandardCharsets.UTF_8);
                sb.append(bodyString);
                log.info("======\n{}", bodyString);
                DataBufferUtils.release(buffer);
            });
            return sb.toString();
        }
    
        private ServerHttpRequest generateNewRequest(ServerHttpRequest request, String requestBody) {
            URI ex = UriComponentsBuilder.fromUri(request.getURI()).build(true).toUri();
            ServerHttpRequest newRequest = request.mutate().uri(ex).build();
            DataBuffer dataBuffer = stringBuffer(requestBody);
            Flux<DataBuffer> flux = Flux.just(dataBuffer);
            newRequest = new ServerHttpRequestDecorator(newRequest) {
                @Override
                public Flux<DataBuffer> getBody() {
                    return flux;
                }
            };
            return newRequest;
        }
    
        private DataBuffer stringBuffer(String value) {
            byte[] bytes = value.getBytes(StandardCharsets.UTF_8);
            NettyDataBufferFactory nettyDataBufferFactory = new NettyDataBufferFactory(ByteBufAllocator.DEFAULT);
            DataBuffer buffer = nettyDataBufferFactory.allocateBuffer(bytes.length);
            buffer.write(bytes);
            return buffer;
        }
    
        @Override
        public int getOrder() {
            return -5;
        }
    }

发起请求输出打印

2019-05-24 22:12:51.644  INFO 10688 --- [ctor-http-nio-3] c.m.d.gateway.filter.RequestBodyFilter   : requestbody: 
     
    2019-05-24 22:12:51.654  INFO 10688 --- [ctor-http-nio-3] com.mt.demo.gateway.filter.MyFilter2     : this is a pre filter2
    2019-05-24 22:12:52.211  INFO 10688 --- [ctor-http-nio-3] com.mt.demo.gateway.filter.MyFilter      : this is a pre filter
    2019-05-24 22:12:52.228  INFO 10688 --- [ctor-http-nio-3] c.m.d.gateway.filter.RequestBodyFilter   : ======
    {
    	"a": "abeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"b": "bbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"c": "cbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"d": "dbeqwertyuiopa
    2019-05-24 17:12:52.230  INFO 10688 --- [ctor-http-nio-3] c.m.d.gateway.filter.RequestBodyFilter   : ======
    sdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"e": "ebeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"ae": "abeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"be": "bbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"ce": "cbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"de": "dbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"ee": "ebeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"aee": "abeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"bee": "bbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"cee": "cbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"dee": "dbeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"eee": "ebeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"aeee": "abeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"beee": "beqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"ceee": "ceqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"deee": "eqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopd",
    	"eeee": "eqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiope",
    	"asdfeee": "aeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"beedsfe": "beqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"ceesde": "ceqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"deesdfe": "deqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"eeesde": "eeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuioeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbn",
    	"aaaaaaa": "aeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"bccccccccc": "eqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopb",
    	"cdddddd": "ceqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"dddddddd": "deqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop",
    	"edddddddd": "eqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiopeqwertyuiopasdfghjklzxcvbnm,asdfghjklqwertyuiop"
    }
    2019-05-24 22:12:52.245  INFO 10688 --- [ioEventLoop-4-1] com.mt.demo.gateway.filter.MyFilter      : websession: 46fad4ce-4137-49c2-b694-93f5f140e2d9

可以看到subscribe的消息体延时收到

#### 第二种获取方式 ####

这种方式在测试的时候没有问题，但是进入生产环境会报

LEAK: ByteBuf. release () was not called before it’s garbage-collected

但是没找到这种方法怎么去释放buffer

@Slf4j
    @Component
    public class RequestBodyFilter1 implements GlobalFilter, Ordered {
    
        private static final List<HttpMessageReader<?>> MESSAGE_READERS = HandlerStrategies.withDefaults().messageReaders();
    
        @Override
        public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
            if (HttpMethod.POST.equals(exchange.getRequest().getMethod()) && null != exchange.getRequest().getHeaders().getContentType()
                    && exchange.getRequest().getHeaders().getContentType().includes(MediaType.APPLICATION_JSON)
                    && !exchange.getRequest().getHeaders().getContentType().includes(MediaType.MULTIPART_FORM_DATA)) {
    
                return readBody(exchange, chain);
            }
            return chain.filter(exchange);
        }
    
        private Mono<Void> readBody(ServerWebExchange exchange, GatewayFilterChain chain) {
            return DataBufferUtils.join(exchange.getRequest().getBody()).flatMap(dataBuffer -> {
                DataBufferUtils.retain(dataBuffer);
                Flux<DataBuffer> cachedFlux = Flux.defer(() -> Flux.just(dataBuffer.slice(0, dataBuffer.readableByteCount())));
    
                ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {
                    @Override
                    public Flux<DataBuffer> getBody() {
                        return cachedFlux;
                    }
                };
                ServerWebExchange mutatedExchange = exchange.mutate().request(mutatedRequest).build();
    
                return ServerRequest.create(mutatedExchange, MESSAGE_READERS).bodyToMono(String.class)
                        .doOnNext(objectValue -> {
                            log.info("----request body: \n{}\n", objectValue);
                        })
                        .then(chain.filter(mutatedExchange));
            });
        }
    
        @Override
        public int getOrder() {
            return -5;
        }
    }

#### 第三种获取方式 ####

目前测试这种方式没有内存泄漏的问题，也能够获取到完整的RequestBody

@Slf4j
    @Component
    public class RequestBodyFilter2 implements GlobalFilter, Ordered {
    
        @Override
        public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
            if (HttpMethod.POST.equals(exchange.getRequest().getMethod()) && null != exchange.getRequest().getHeaders().getContentType()
                    && exchange.getRequest().getHeaders().getContentType().includes(MediaType.APPLICATION_JSON)
                    && !exchange.getRequest().getHeaders().getContentType().includes(MediaType.MULTIPART_FORM_DATA)) {
    
                return DataBufferUtils.join(exchange.getRequest().getBody()).map(dataBuffer -> {
                    byte[] bytes = new byte[dataBuffer.readableByteCount()];
                    dataBuffer.read(bytes);
                    DataBufferUtils.release(dataBuffer);
                    return bytes;
                }).flatMap(bodyBytes -> {
                    String msg = new String(bodyBytes, StandardCharsets.UTF_8);
                    log.info("requestBody: \n {}", msg);
                    exchange.getAttributes().put(Constants.CACHE_REQUEST_BODY, msg);
                    return chain.filter(exchange.mutate().request(generateNewRequest(exchange.getRequest(), bodyBytes)).build());
                });
            }
            return chain.filter(exchange);
        }
    
        private ServerHttpRequest generateNewRequest(ServerHttpRequest request, byte[] bytes) {
            URI ex = UriComponentsBuilder.fromUri(request.getURI()).build(true).toUri();
            ServerHttpRequest newRequest = request.mutate().uri(ex).build();
            DataBuffer dataBuffer = stringBuffer(bytes);
            Flux<DataBuffer> flux = Flux.just(dataBuffer);
            newRequest = new ServerHttpRequestDecorator(newRequest) {
                @Override
                public Flux<DataBuffer> getBody() {
                    return flux;
                }
            };
            return newRequest;
        }
    
        private DataBuffer stringBuffer(byte[] bytes) {
            NettyDataBufferFactory nettyDataBufferFactory = new NettyDataBufferFactory(ByteBufAllocator.DEFAULT);
            return nettyDataBufferFactory.wrap(bytes);
        }
    
    
        @Override
        public int getOrder() {
            return -5;
        }
    }

从第三种方式中可以看到

exchange.getAttributes().put(Constants.CACHE_REQUEST_BODY, msg);

将RequestBody存入exchange，就可以在后续流程通过exchange来获取

[GITHUB代码地址][GITHUB]

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![在这里插入图片描述][70]

[GITHUB]: https://github.com/yingziisme/spring-cloud-gateway-demo
[70]: /images/20211214/23b11649ff5144f9bbd761a42a66cd2a.png