SpringCloud Gateway之请求应答日志打印方式

Gateway请求应答日志打印

请求应答日志时在日常开发调试问题的重要手段之一，那么如何基于Spring Cloud Gateway做呢，请看我上代码。

第一步

创建RecorderServerHttpRequestDecorator，缓存请求参数，解决body只能读一次问题。

public class RecorderServerHttpRequestDecorator extends ServerHttpRequestDecorator { 
    private final List<DataBuffer> dataBuffers = new ArrayList<>(); 
    public RecorderServerHttpRequestDecorator(ServerHttpRequest delegate) {
        super(delegate);
        super.getBody().map(dataBuffer -> {
            dataBuffers.add(dataBuffer);
            return dataBuffer;
        }).subscribe();
    }
 
    @Override
    public Flux<DataBuffer> getBody() {
        return copy();
    }
 
    private Flux<DataBuffer> copy() {
        return Flux.fromIterable(dataBuffers)
                .map(buf -> buf.factory().wrap(buf.asByteBuffer()));
    }  
}

第二步

创建访问日志全局过滤器,然后在此过滤器进行日志构造。

@Slf4j
public class AccessLogGlobalFilter implements GlobalFilter , Ordered { 
    private static final String REQUEST_PREFIX = "Request Info [ "; 
    private static final String REQUEST_TAIL = " ]"; 
    private static final String RESPONSE_PREFIX = "Response Info [ "; 
    private static final String RESPONSE_TAIL = " ]"; 
    private StringBuilder normalMsg = new StringBuilder();
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        RecorderServerHttpRequestDecorator requestDecorator = new RecorderServerHttpRequestDecorator(request);
        InetSocketAddress address = requestDecorator.getRemoteAddress();
        HttpMethod method = requestDecorator.getMethod();
        URI url = requestDecorator.getURI();
        HttpHeaders headers = requestDecorator.getHeaders();
        Flux<DataBuffer> body = requestDecorator.getBody();
        //读取requestBody传参
        AtomicReference<String> requestBody = new AtomicReference<>("");
        body.subscribe(buffer -> {
            CharBuffer charBuffer = StandardCharsets.UTF_8.decode(buffer.asByteBuffer());
            requestBody.set(charBuffer.toString());
        });
        String requestParams = requestBody.get();
        normalMsg.append(REQUEST_PREFIX);
        normalMsg.append(";header=").append(headers);
        normalMsg.append(";params=").append(requestParams);
        normalMsg.append(";address=").append(address.getHostName() + address.getPort());
        normalMsg.append(";method=").append(method.name());
        normalMsg.append(";url=").append(url.getPath());
        normalMsg.append(REQUEST_TAIL);
 
        ServerHttpResponse response = exchange.getResponse();
 
        DataBufferFactory bufferFactory = response.bufferFactory();
        normalMsg.append(RESPONSE_PREFIX);
        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(response) {
            @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.map(dataBuffer -> {
                        // probably should reuse buffers
                        byte[] content = new byte[dataBuffer.readableByteCount()];
                        dataBuffer.read(content);
                        String responseResult = new String(content, Charset.forName("UTF-8"));
                        normalMsg.append("status=").append(this.getStatusCode());
                        normalMsg.append(";header=").append(this.getHeaders());
                        normalMsg.append(";responseResult=").append(responseResult);
                        normalMsg.append(RESPONSE_TAIL);
                        log.info(normalMsg.toString());
                        return bufferFactory.wrap(content);
                    }));
                }
                return super.writeWith(body); // if body is not a flux. never got there.
            }
        };
 
        return chain.filter(exchange.mutate().request(requestDecorator).response(decoratedResponse).build());
    }
 
    @Override
    public int getOrder() {
        return -2;
    } 
}

最后结果：

Request Info [ ;header={cache-control=[no-cache], Postman-Token=[790488a5-a284-4a0e-968f-1b588cb26688], Content-Type=[application/json], User-Agent=[PostmanRuntime/3.0.9], Accept=[*/*], Host=[localhost:8084], cookie=[JSESSIONID=E161AC22204E626FBE6E96EE7B62EE70], accept-encoding=[gzip, deflate], content-length=[13], Connection=[keep-alive]};params={"name":"ss"};address=0:0:0:0:0:0:0:159621;method=POST;url=/account/testBody ]Response Info [ ;status=200;header={Content-Type=[text/plain;charset=UTF-8], Content-Length=[41], Date=[Mon, 18 Mar 2019 08:21:57 GMT]};responseResult=account hellowordAccountEntity{name='ss'} ]

以上代码即可完成请求应答日志打印功能。

Gateway全局请求日志打印

实现GlobalFilter则所有该自定义Filter会对所有的路由生效。

把请求体的数据存入exchange

便于打印日志时获取

package com.qykj.gateway.filter;
import com.qykj.gateway.ConstantFilter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
/**
 * @calssName AppCacheRequestBodyFilter
 * @Description 将 request body 中的内容 copy 一份，记录到 exchange 的一个自定义属性中
 * @Author jiangshaoneng
 * @DATE 2020/9/27 14:42
 */
public class GlobalCacheRequestBodyFilter implements GlobalFilter, Ordered {
    private static final Logger logger = LoggerFactory.getLogger(GlobalCacheRequestBodyFilter.class);
    private int order;
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //logger.info("GlobalCacheRequestBodyFilter ...");
        // 将 request body 中的内容 copy 一份，记录到 exchange 的一个自定义属性中
        Object cachedRequestBodyObject = exchange.getAttributeOrDefault(ConstantFilter.CACHED_REQUEST_BODY_OBJECT_KEY, null);
        // 如果已经缓存过，略过
        if (cachedRequestBodyObject != null) {
            return chain.filter(exchange);
        }
        // 如果没有缓存过，获取字节数组存入 exchange 的自定义属性中
        return DataBufferUtils.join(exchange.getRequest().getBody())
                .map(dataBuffer -> {
                    byte[] bytes = new byte[dataBuffer.readableByteCount()];
                    dataBuffer.read(bytes);
                    DataBufferUtils.release(dataBuffer);
                    return bytes;
                }).defaultIfEmpty(new byte[0])
                .doOnNext(bytes -> exchange.getAttributes().put(ConstantFilter.CACHED_REQUEST_BODY_OBJECT_KEY, bytes))
                .then(chain.filter(exchange));
    }
    @Override
    public int getOrder() {
        return this.order;
    }
    public GlobalCacheRequestBodyFilter(int order){
        this.order = order;
    }
}

编写全局日志拦截器代码

/**
 * @calssName LogFilter
 * @Description 全局日志打印,请求日志以及返回日志,并在返回结果日志中添加请求时间
 * @Author jiangshaoneng
 * @DATE 2020/9/25 14:54
 */
public class GlobalLogFilter implements GlobalFilter, Ordered {
    private static final Logger logger = LoggerFactory.getLogger(GlobalLogFilter.class);
    private int order;
    private static final String REQUEST_PREFIX = "\n--------------------------------- Request  Info -----------------------------";
    private static final String REQUEST_TAIL   = "\n-----------------------------------------------------------------------------";
    private static final String RESPONSE_PREFIX = "\n--------------------------------- Response Info -----------------------------";
    private static final String RESPONSE_TAIL   = "\n-------------------------------------------------------------------------->>>";
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        long start = DateUtil.getCurrentTime();
        StringBuilder reqMsg = new StringBuilder();
        StringBuilder resMsg = new StringBuilder();
        // 获取请求信息
        ServerHttpRequest request = exchange.getRequest();
        InetSocketAddress address = request.getRemoteAddress();
        String method = request.getMethodValue();
        URI uri = request.getURI();
        HttpHeaders headers = request.getHeaders();
        // 获取请求body
        Object cachedRequestBodyObject = exchange.getAttributeOrDefault(ConstantFilter.CACHED_REQUEST_BODY_OBJECT_KEY, null);
        byte[] body = (byte[]) cachedRequestBodyObject;
        String params = new String(body);
        // 获取请求query
        Map queryMap = request.getQueryParams();
        String query = JSON.toJSONString(queryMap);
        // 拼接请求日志
        reqMsg.append(REQUEST_PREFIX);
        reqMsg.append("\n header=").append(headers);
        reqMsg.append("\n query=").append(query);
        reqMsg.append("\n params=").append(params);
        reqMsg.append("\n address=").append(address.getHostName()).append(address.getPort());
        reqMsg.append("\n method=").append(method);
        reqMsg.append("\n url=").append(uri.getPath());
        reqMsg.append(REQUEST_TAIL);
        logger.info(reqMsg.toString()); // 打印入参日志
        ServerHttpResponse response = exchange.getResponse();
        DataBufferFactory bufferFactory = response.bufferFactory();
        resMsg.append(RESPONSE_PREFIX);
        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(response) {
            @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.map(dataBuffer -> {
                        byte[] content = new byte[dataBuffer.readableByteCount()];
                        dataBuffer.read(content);
                        String responseResult = new String(content, Charset.forName("UTF-8"));
                        resMsg.append("\n status=").append(this.getStatusCode());
                        resMsg.append("\n header=").append(this.getHeaders());
                        resMsg.append("\n responseResult=").append(responseResult);
                        resMsg.append(RESPONSE_TAIL);
                        // 计算请求时间
                        long end = DateUtil.getCurrentTime();
                        long time = end - start;
                        resMsg.append("耗时ms:").append(time);
                        logger.info(resMsg.toString()); // 打印结果日志
                        return bufferFactory.wrap(content);
                    }));
                }
                return super.writeWith(body);
            }
        };
        return chain.filter(exchange.mutate().response(decoratedResponse).build());
    }
    @Override
    public int getOrder() {
        return this.order;
    }
    public GlobalLogFilter(int order){
        this.order = order;
    }
}

在代码中配置全局拦截器

/**
 * @calssName GatewayConfig
 * @Description 网关配置
 * @Author jiangshaoneng
 * @DATE 2020/9/25 14:26
 */
@Configuration
public class GatewayConfig {
    /**
     * 全局过滤器：请求日志打印
     */
    @Bean
    public GlobalLogFilter globalLogFilter(){
        // 该值越小权重却大，所以应根据具体项目配置。需要尽早的获取到参数，一般会是一个比较小的值
        return new GlobalLogFilter(-20); 
    }
    
    // 其他的路由配置 ... 
}

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