gateway：增加访问日志，待优化~

yudao-gateway/src/main/java/cn/iocoder/yudao/gateway/filter/logging/AccessLogFilter.java

+package cn.iocoder.yudao.gateway.filter.logging;
+
+import cn.hutool.core.util.ObjectUtil;
+import com.alibaba.nacos.common.utils.StringUtils;
+import lombok.extern.slf4j.Slf4j;
+import org.reactivestreams.Publisher;
+import org.springframework.cloud.gateway.filter.GatewayFilterChain;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.cloud.gateway.filter.factory.rewrite.CachedBodyOutputMessage;
+import org.springframework.cloud.gateway.route.Route;
+import org.springframework.cloud.gateway.support.BodyInserterContext;
+import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
+import org.springframework.core.Ordered;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferFactory;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
+import org.springframework.stereotype.Component;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.server.HandlerStrategies;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.server.ServerWebExchange;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Date;
+import java.util.List;
+import java.util.Map;
+
+@Slf4j
+@Component
+public class AccessLogFilter implements GlobalFilter, Ordered {
+
+    private final List<HttpMessageReader<?>> messageReaders = HandlerStrategies.withDefaults().messageReaders();
+
+    @Override
+    public int getOrder() {
+        return -100;
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
+
+        ServerHttpRequest request = exchange.getRequest();
+
+        // 请求路径
+        String requestPath = request.getPath().pathWithinApplication().value();
+
+        Route route = getGatewayRoute(exchange);
+
+
+//        String ipAddress = WebUtils.getServerHttpRequestIpAddress(request);
+        String ipAddress = "127.0.0.1";
+
+        GatewayLog gatewayLog = new GatewayLog();
+        gatewayLog.setSchema(request.getURI().getScheme());
+        gatewayLog.setRequestMethod(request.getMethodValue());
+        gatewayLog.setRequestPath(requestPath);
+        gatewayLog.setTargetServer(route.getId());
+        gatewayLog.setRequestTime(new Date());
+        gatewayLog.setIp(ipAddress);
+
+        MediaType mediaType = request.getHeaders().getContentType();
+
+        if(MediaType.APPLICATION_FORM_URLENCODED.isCompatibleWith(mediaType) || MediaType.APPLICATION_JSON.isCompatibleWith(mediaType)){
+            return writeBodyLog(exchange, chain, gatewayLog);
+        }else{
+            return writeBasicLog(exchange, chain, gatewayLog);
+        }
+    }
+
+    private Mono<Void> writeBasicLog(ServerWebExchange exchange, GatewayFilterChain chain, GatewayLog accessLog) {
+        StringBuilder builder = new StringBuilder();
+        MultiValueMap<String, String> queryParams = exchange.getRequest().getQueryParams();
+        for (Map.Entry<String, List<String>> entry : queryParams.entrySet()) {
+            builder.append(entry.getKey()).append("=").append(StringUtils.join(entry.getValue(), ","));
+        }
+        accessLog.setRequestBody(builder.toString());
+
+        //获取响应体
+        ServerHttpResponseDecorator decoratedResponse = recordResponseLog(exchange, accessLog);
+
+        return chain.filter(exchange.mutate().response(decoratedResponse).build())
+                .then(Mono.fromRunnable(() -> {
+                    // 打印日志
+                    writeAccessLog(accessLog);
+                }));
+    }
+
+
+    /**
+     * 解决 request body 只能读取一次问题，
+     * 参考: org.springframework.cloud.gateway.filter.factory.rewrite.ModifyRequestBodyGatewayFilterFactory
+     * @param exchange
+     * @param chain
+     * @param gatewayLog
+     * @return
+     */
+    @SuppressWarnings("unchecked")
+    private Mono writeBodyLog(ServerWebExchange exchange, GatewayFilterChain chain, GatewayLog gatewayLog) {
+        ServerRequest serverRequest = ServerRequest.create(exchange,messageReaders);
+
+        Mono<String> modifiedBody = serverRequest.bodyToMono(String.class)
+                .flatMap(body ->{
+                    gatewayLog.setRequestBody(body);
+                    return Mono.just(body);
+                });
+
+        // 通过 BodyInserter 插入 body(支持修改body), 避免 request body 只能获取一次
+        BodyInserter bodyInserter = BodyInserters.fromPublisher(modifiedBody, String.class);
+        HttpHeaders headers = new HttpHeaders();
+        headers.putAll(exchange.getRequest().getHeaders());
+        // the new content type will be computed by bodyInserter
+        // and then set in the request decorator
+        headers.remove(HttpHeaders.CONTENT_LENGTH);
+
+        CachedBodyOutputMessage outputMessage = new CachedBodyOutputMessage(exchange, headers);
+
+        return bodyInserter.insert(outputMessage,new BodyInserterContext())
+                .then(Mono.defer(() -> {
+                    // 重新封装请求
+                    ServerHttpRequest decoratedRequest = requestDecorate(exchange, headers, outputMessage);
+
+                    // 记录响应日志
+                    ServerHttpResponseDecorator decoratedResponse = recordResponseLog(exchange, gatewayLog);
+
+                    // 记录普通的
+                    return chain.filter(exchange.mutate().request(decoratedRequest).response(decoratedResponse).build())
+                            .then(Mono.fromRunnable(() -> {
+                                // 打印日志
+                                writeAccessLog(gatewayLog);
+                            }));
+                }));
+    }
+
+    /**
+     * 打印日志
+     * @author javadaily
+     * @date 2021/3/24 14:53
+     * @param gatewayLog 网关日志
+     */
+    private void writeAccessLog(GatewayLog gatewayLog) {
+        log.info(gatewayLog.toString());
+    }
+
+
+
+    private Route getGatewayRoute(ServerWebExchange exchange) {
+        return exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);
+    }
+
+
+    /**
+     * 请求装饰器，重新计算 headers
+     * @param exchange
+     * @param headers
+     * @param outputMessage
+     * @return
+     */
+    private ServerHttpRequestDecorator requestDecorate(ServerWebExchange exchange, HttpHeaders headers,
+                                                       CachedBodyOutputMessage outputMessage) {
+        return new ServerHttpRequestDecorator(exchange.getRequest()) {
+            @Override
+            public HttpHeaders getHeaders() {
+                long contentLength = headers.getContentLength();
+                HttpHeaders httpHeaders = new HttpHeaders();
+                httpHeaders.putAll(super.getHeaders());
+                if (contentLength > 0) {
+                    httpHeaders.setContentLength(contentLength);
+                } else {
+                    // TODO: this causes a 'HTTP/1.1 411 Length Required' // on
+                    // httpbin.org
+                    httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");
+                }
+                return httpHeaders;
+            }
+
+            @Override
+            public Flux<DataBuffer> getBody() {
+                return outputMessage.getBody();
+            }
+        };
+    }
+
+
+    /**
+     * 记录响应日志
+     * 通过 DataBufferFactory 解决响应体分段传输问题。
+     */
+    private ServerHttpResponseDecorator recordResponseLog(ServerWebExchange exchange, GatewayLog gatewayLog) {
+        ServerHttpResponse response = exchange.getResponse();
+        DataBufferFactory bufferFactory = response.bufferFactory();
+
+        return new ServerHttpResponseDecorator(response) {
+            @Override
+            public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
+                if (body instanceof Flux) {
+                    Date responseTime = new Date();
+                    gatewayLog.setResponseTime(responseTime);
+                    // 计算执行时间
+                    long executeTime = (responseTime.getTime() - gatewayLog.getRequestTime().getTime());
+
+                    gatewayLog.setExecuteTime(executeTime);
+
+                    // 获取响应类型，如果是 json 就打印
+                    String originalResponseContentType = exchange.getAttribute(ServerWebExchangeUtils.ORIGINAL_RESPONSE_CONTENT_TYPE_ATTR);
+
+
+                    if (ObjectUtil.equal(this.getStatusCode(), HttpStatus.OK)
+                            && StringUtils.isNotBlank(originalResponseContentType)
+                            && originalResponseContentType.contains("application/json")) {
+
+                        Flux<? extends DataBuffer> fluxBody = Flux.from(body);
+                        return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
+
+                            // 合并多个流集合，解决返回体分段传输
+                            DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
+                            DataBuffer join = dataBufferFactory.join(dataBuffers);
+                            byte[] content = new byte[join.readableByteCount()];
+                            join.read(content);
+
+                            // 释放掉内存
+                            DataBufferUtils.release(join);
+                            String responseResult = new String(content, StandardCharsets.UTF_8);
+
+
+
+                            gatewayLog.setResponseData(responseResult);
+
+                            return bufferFactory.wrap(content);
+                        }));
+                    }
+                }
+                // if body is not a flux. never got there.
+                return super.writeWith(body);
+            }
+        };
+    }
+}

yudao-gateway/src/main/java/cn/iocoder/yudao/gateway/filter/logging/GatewayLog.java

+package cn.iocoder.yudao.gateway.filter.logging;
+
+import lombok.Data;
+
+import java.util.Date;
+
+@Data
+public class GatewayLog {
+    /**访问实例*/
+    private String targetServer;
+    /**请求路径*/
+    private String requestPath;
+    /**请求方法*/
+    private String requestMethod;
+    /**协议 */
+    private String schema;
+    /**请求体*/
+    private String requestBody;
+    /**响应体*/
+    private String responseData;
+    /**请求ip*/
+    private String ip;
+ /**请求时间*/
+    private Date requestTime;
+ /**响应时间*/
+    private Date responseTime;
+    /**执行时间*/
+    private long executeTime;
+}

yudao-gateway/src/main/java/cn/iocoder/yudao/gateway/filter/web/CacheRequestBodyFilter.java

+package cn.iocoder.yudao.gateway.filter.web;
+
+import cn.hutool.core.util.ReflectUtil;
+import org.springframework.cloud.gateway.filter.GatewayFilterChain;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.cloud.gateway.filter.factory.rewrite.CachedBodyOutputMessage;
+import org.springframework.cloud.gateway.support.BodyInserterContext;
+import org.springframework.core.Ordered;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.server.HandlerStrategies;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.server.ServerWebExchange;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+import java.util.function.Function;
+
+/**
+ * 缓存 Request Body 和 的过滤器
+ *
+ * 小知识：Request Body 都是无法重复读取的，所以需要实现一个缓存的。
+ * 从功能上，它类似 yudao-spring-boot-starter-web 的 CacheRequestBodyFilter 过滤器
+ *
+ * 实现基本是拷贝 {@link org.springframework.cloud.gateway.filter.factory.rewrite.ModifyRequestBodyGatewayFilterFactory} 类
+ *
+ * @author 芋道源码
+ */
+@Component
+public class CacheRequestBodyFilter implements GlobalFilter, Ordered {
+
+    private final List<HttpMessageReader<?>> messageReaders = HandlerStrategies.withDefaults().messageReaders();
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
+        ServerRequest serverRequest = ServerRequest.create(exchange, messageReaders);
+
+        // TODO: flux or mono
+        Mono<String> modifiedBody = serverRequest.bodyToMono(String.class);
+//                .flatMap()
+//                .switchIfEmpty(Mono.just(""));
+
+        BodyInserter bodyInserter = BodyInserters.fromPublisher(modifiedBody, String.class);
+        HttpHeaders headers = new HttpHeaders();
+        headers.putAll(exchange.getRequest().getHeaders());
+
+        // the new content type will be computed by bodyInserter
+        // and then set in the request decorator
+        headers.remove(HttpHeaders.CONTENT_LENGTH);
+
+        CachedBodyOutputMessage outputMessage = new CachedBodyOutputMessage(exchange, headers);
+        return bodyInserter.insert(outputMessage, new BodyInserterContext())
+                // .log("modify_request", Level.INFO)
+                .then(Mono.defer(() -> {
+                    ServerHttpRequest decorator = decorate(exchange, headers, outputMessage);
+                    return chain.filter(exchange.mutate().request(decorator).build());
+                })).onErrorResume((Function<Throwable, Mono<Void>>) throwable -> release(exchange,
+                        outputMessage, throwable));
+    }
+
+    @Override
+    public int getOrder() {
+        // 必须小于等于 -2，否则无法获取响应结果. 因为 WebClientWriteResponseFilter 和 NettyWriteResponseFilter 是 -1，优先级要高于它们
+        return -2;
+    }
+
+    protected Mono<Void> release(ServerWebExchange exchange, CachedBodyOutputMessage outputMessage,
+                                 Throwable throwable) {
+        // add by 芋道源码：由于 CachedBodyOutputMessage 的 isCached 非 public 方法，所以只能反射调用
+        if ((boolean) ReflectUtil.getFieldValue(outputMessage, "cached")) {
+            return outputMessage.getBody().map(DataBufferUtils::release).then(Mono.error(throwable));
+        }
+        return Mono.error(throwable);
+    }
+
+    ServerHttpRequestDecorator decorate(ServerWebExchange exchange, HttpHeaders headers,
+                                        CachedBodyOutputMessage outputMessage) {
+        return new ServerHttpRequestDecorator(exchange.getRequest()) {
+
+            @Override
+            public HttpHeaders getHeaders() {
+                long contentLength = headers.getContentLength();
+                HttpHeaders httpHeaders = new HttpHeaders();
+                httpHeaders.putAll(headers);
+                if (contentLength > 0) {
+                    httpHeaders.setContentLength(contentLength);
+                }
+                else {
+                    // TODO: this causes a 'HTTP/1.1 411 Length Required' // on
+                    // httpbin.org
+                    httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");
+                }
+                return httpHeaders;
+            }
+
+            @Override
+            public Flux<DataBuffer> getBody() {
+                return outputMessage.getBody();
+            }
+        };
+    }
+
+}