目录
1.BUG描述
- BUG描述
在Spring Cloud Gateway使用编码的方式实现一个全局拦截器,在全局拦截器中想要打印响应日志。
于是自己装饰了一个具有打印日志功能的ServerHttpResponseDecorator,但是在转发后的服务返回响应的时候,ServerHttpResponseDecorator的writeWith却并没有执行
java
@Component
@Slf4j
public class CustomGlobaFilter implements GlobalFilter, Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
//响应日志
return handleResponse(exchange, chain);
}
public Mono<Void> handleResponse(ServerWebExchange exchange, GatewayFilterChain chain) {
try {
ServerHttpResponse originalResponse = exchange.getResponse();
// 缓存数据的工厂
DataBufferFactory bufferFactory = originalResponse.bufferFactory();
// 拿到响应码
HttpStatus statusCode = originalResponse.getStatusCode();
if (statusCode == HttpStatus.OK) {
// 装饰,增强能力
ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
// 等调用完转发的接口后才会执行
@Override
public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
log.info("body instanceof Flux: {}", (body instanceof Flux));
if (body instanceof Flux) {
Flux<? extends DataBuffer> fluxBody = Flux.from(body);
// 往返回值里写数据
// 拼接字符串
return super.writeWith(
fluxBody.map(dataBuffer -> {
byte[] content = new byte[dataBuffer.readableByteCount()];
dataBuffer.read(content);
//释放掉内存
DataBufferUtils.release(dataBuffer);
// 构建日志
StringBuilder sb2 = new StringBuilder(200);
List<Object> rspArgs = new ArrayList<>();
rspArgs.add(originalResponse.getStatusCode());
//data
String data = new String(content, StandardCharsets.UTF_8);
sb2.append(data);
// 打印日志
log.info("响应结果:" + data);
return bufferFactory.wrap(content);
}));
} else {
// 8. 调用失败,返回一个规范的错误码
log.error("<--- {} 响应code异常", getStatusCode());
}
return super.writeWith(body);
}
};
// 设置 response 对象为装饰过的
return chain.filter(exchange.mutate().response(decoratedResponse).build());
}
// 降级处理返回数据
return chain.filter(exchange);
} catch (Exception e) {
log.error("网关处理响应异常" + e);
return chain.filter(exchange);
}
}
@Override
public int getOrder() {
return 0;
}
}
2.BUG解决
将这种写法
java
@Slf4j
@Component
@Order(-2) <--------------将这个
public class CustomGlobalFilter implements GlobalFilter , Ordered {
........省略
}
改为这种方式
java
@Override
public int getOrder() {
return -2;
}
3.BUG分析
查阅官网文档
- 官网文档案例采用的是实现接口的方式
java
@Override
public int getOrder() {
return -2;
}
- 查阅资料之后没有找到详细的解答,还是遵循官方的规范吧,时间有限,不纠结,意义不大。