spring cloud gateway为了记录访问记录,需要记录请求体里面的内容,但是 request body是只能读取一次的,如果读取以后不封装回去,则会造成后面的服务无法读取body数据. 在网关里添加一个过滤器RequestRecordFilter类:
@Slf4j
@Component
public class RequestRecordFilter implements GlobalFilter, Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest request = exchange.getRequest();
URI requestUri = request.getURI();
//只记录 http 请求(包含 https)
String schema = requestUri.getScheme();
if ((!"http".equals(schema) && !"https".equals(schema))){
return chain.filter(exchange);
}
AccessRecord accessRecord = new AccessRecord();
accessRecord.setPath(requestUri.getPath());
accessRecord.setQueryString(request.getQueryParams());
exchange.getAttributes().put("startTime", System.currentTimeMillis());
String method = request.getMethodValue();
String contentType = request.getHeaders().getFirst("Content-Type");
//此处要排除流文件类型,比如上传的文件
if ("POST".equals(method) && !contentType.startsWith("multipart/form-data")){
String bodyStr = resolveBodyFromRequest(request);
//下面将请求体再次封装写回到 request 里,传到下一级.
URI ex = UriComponentsBuilder.fromUri(requestUri).build(true).toUri();
ServerHttpRequest newRequest = request.mutate().uri(ex).build();
DataBuffer bodyDataBuffer = stringBuffer(bodyStr);
Flux<DataBuffer> bodyFlux = Flux.just(bodyDataBuffer);
newRequest = new ServerHttpRequestDecorator(newRequest) {
@Override
public Flux<DataBuffer> getBody() {
return bodyFlux;
}
};
accessRecord.setBody(formatStr(bodyStr));
ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
return returnMono(chain, newExchange, accessRecord);
} else {
return returnMono(chain, exchange, accessRecord);
}
}
private Mono<Void> returnMono(GatewayFilterChain chain,ServerWebExchange exchange, AccessRecord accessRecord){
return chain.filter(exchange).then(Mono.fromRunnable(()->{
Long startTime = exchange.getAttribute("startTime");
if (startTime != null){
long executeTime = (System.currentTimeMillis() - startTime);
accessRecord.setExpendTime(executeTime);
accessRecord.setHttpCode(Objects.requireNonNull(exchange.getResponse().getStatusCode()).value());
writeAccessLog(JSON.toJSONString(accessRecord) + "\r\n");
}
}));
}
@Override
public int getOrder() {
return 1;
}
/**
* 获取请求体中的字符串内容
* @param serverHttpRequest
* @return
*/
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();
}
/**
* 去掉空格,换行和制表符
* @param str
* @return
*/
private String formatStr(String str){
if (str != null && str.length() > 0) {
Pattern p = Pattern.compile("\\s*|\t|\r|\n");
Matcher m = p.matcher(str);
return m.replaceAll("");
}
return str;
}
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;
}
/**
* 访问记录对象
*/
@Data
private class AccessRecord{
private String path;
private String body;
private MultiValueMap<String,String> queryString;
private long expendTime;
private int httpCode;
}
private void writeAccessLog(String str){
File file = new File("access.log");
if (!file.exists()){
try {
if (file.createNewFile()){
file.setWritable(true);
}
} catch (IOException e) {
log.error("创建访问日志文件失败.{}",e.getMessage(),e);
}
}
try(FileWriter fileWriter = new FileWriter(file.getName(),true)){
fileWriter.write(str);
} catch (IOException e) {
log.error("写访问日志到文件失败. {}", e.getMessage(),e);
}
}
}
网上有个获取 body的写法, 但是这种写法对请求体的字符串长度有限制,稍微长一点, 就会转换不完整,方法如下:
private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest) {
//获取请求体
Flux<DataBuffer> body = serverHttpRequest.getBody();
AtomicReference<String> bodyRef = new AtomicReference<>();
body.subscribe(buffer -> {
CharBuffer charBuffer = StandardCharsets.UTF_8.decode(buffer.asByteBuffer());
DataBufferUtils.release(buffer);
bodyRef.set(charBuffer.toString());
});
//获取request body
return bodyRef.get();
}
对于出现 Only one connection receive subscriber allowed，或者 response is set之类的信息，这个是springboot2.0.5之后的一个bug，需要在类里面添加以下方法去实现（这个是springboot开发成员提供的方法）：
@Bean
public HiddenHttpMethodFilter hiddenHttpMethodFilter() {
return new HiddenHttpMethodFilter() {
@Override
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
return chain.filter(exchange);
}
};
}
