目录
最近在测试环境spring cloud gateway突然出现了异常，在这里记录一下，直接上干货
1、问题背景
测试环境spring cloud gateway遇到以下异常
DataBufferLimitException: Exceeded limit on max bytes to buffer : 262144（超出了缓冲区的最大字节数限制）
乍一看，问题很简单啊，通过配置加大缓存区不就行了啊，于是就在application.yml加了以下配置
java
#将缓存区设置为2m
spring:
codec:
max-in-memory-size: 2MB可是问题又出现了，通过调试发现配置的max-in-memory-size在程序启动初始化确实是生效的。但是有业务调用的时候，此参数的接收值为null,maxInMemorySize还是读取的默认值（256K）。
那咋整，只能从源码入手了。
2、分析源码过程
通过异常日志，可以定位到异常位置
后来发现我们自定义的拦截器获取body的信息是获取方式，代码如下
因为HandlerStrategies.withDefaults() 是每次都需要重新创建对象，并非是spring注入的对象，所以每次获取的都是默认值，导致配置不生效。
3、解决办法
在我们自定的拦截器中注入ServerCodecConfigurer类，通过该类获取配置。这样获取到的就是我们在application.yml中配置的缓存区配置的字节数限制了。
具体代码：
java
@Component
@Slf4j
public class RequestFilter implements GlobalFilter, Ordered {
@Override
public int getOrder() {
return OrderedConstant.HIGHEST_PRECEDENCE;
}
//手动注入ServerCodecConfigurer
@Autowired
ServerCodecConfigurer codecConfigurer;
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
StopWatch stopWatch = new StopWatch();
stopWatch.start();
long startTime = System.currentTimeMillis();
try {
final Log logDTO = new Log();
ServerHttpRequest request = exchange.getRequest();
// 设置X-Request-Id
AtomicReference<String> requestId = new AtomicReference<>(GenerateIdUtils.requestIdWithUUID());
Consumer<HttpHeaders> httpHeadersConsumer = httpHeaders -> {
String headerRequestId = request.getHeaders().getFirst(HeaderConstant.REQUEST_ID);
if (!Strings.isNullOrEmpty(headerRequestId)) {
requestId.set(headerRequestId);
}
logDTO.setRequestId(requestId.get());
httpHeaders.set(HeaderConstant.REQUEST_ID, requestId.get());
httpHeaders.set(HeaderConstant.START_TIME_KEY, String.valueOf(startTime));
};
// codecConfigurer.getReaders()获取pplication.yml中配置的缓存区配置的字节数
ServerRequest serverRequest = ServerRequest.create(exchange,
codecConfigurer.getReaders());
URI requestUri = request.getURI();
String uriQuery = requestUri.getQuery();
String url = requestUri.getPath() + (!Strings.isNullOrEmpty(uriQuery) ? "?" + uriQuery : "");
HttpHeaders headers = request.getHeaders();
MediaType mediaType = headers.getContentType();
String method = request.getMethodValue().toUpperCase();
// 原始请求体
final AtomicReference<String> requestBody = new AtomicReference<>();
final AtomicBoolean newBody = new AtomicBoolean(false);
if (mediaType != null && LogHelper.isUploadFile(mediaType)) {
requestBody.set("上传文件");
} else {
if (method.equals("GET")) {
if (!Strings.isNullOrEmpty(uriQuery)) {
requestBody.set(uriQuery);
}
} else {
newBody.set(true);
}
}
logDTO.setLevel(Log.LEVEL.INFO);
logDTO.setRequestUrl(url);
logDTO.setRequestBody(requestBody.get());
logDTO.setRequestMethod(method);
logDTO.setIp(IpUtils.getClientIp(request));
ServerHttpRequest serverHttpRequest = exchange.getRequest().mutate().headers(httpHeadersConsumer).build();
ServerWebExchange build = exchange.mutate().request(serverHttpRequest).build();
return build.getSession().flatMap(webSession -> {
logDTO.setSessionId(webSession.getId());
if (newBody.get() && headers.getContentLength() > 0) {
Mono<String> bodyToMono = serverRequest.bodyToMono(String.class);
return bodyToMono.flatMap(reqBody -> {
logDTO.setRequestBody(reqBody);
// 重写原始请求
ServerHttpRequestDecorator requestDecorator = new ServerHttpRequestDecorator(exchange.getRequest()) {
@Override
public Flux<DataBuffer> getBody() {
NettyDataBufferFactory nettyDataBufferFactory = new NettyDataBufferFactory(new UnpooledByteBufAllocator(false));
DataBuffer bodyDataBuffer = nettyDataBufferFactory.wrap(reqBody.getBytes());
return Flux.just(bodyDataBuffer);
}
};
return chain.filter(exchange.mutate()
.request(requestDecorator)
.build()).then(LogHelper.doRecord(logDTO));
});
} else {
return chain.filter(exchange).then(LogHelper.doRecord(logDTO));
}
});
} catch (Exception e) {
log.error("请求日志打印出现异常", e);
return chain.filter(exchange);
}
}
}