很多朋友在使用SpringCloudGateway的时候可能都碰到过以下几个问题
SpringCloudGateway中如何读取Post请求体
private BodyInserter getBodyInserter(ServerWebExchange exchange) {
ServerRequest serverRequest = new DefaultServerRequest(exchange);
Mono<String> modifiedBody = serverRequest.bodyToMono(String.class)
.flatMap(body -> {
//这里的body就是Post的请求体
});
BodyInserter bodyInserter = BodyInserters.fromPublisher(modifiedBody, String.class);
return bodyInserter;
}
SpringCloudGateway中Post请求参数只能读取一次
这是因为Gateway默认使用的是SpringWebflux，解决这个问题需要容重新构造一个request来替换原先的request
HttpHeaders headers=new HttpHeaders();
CachedBodyOutputMessage outputMessage = new CachedBodyOutputMessage(exchange, headers);
ServerHttpRequestDecorator decorator = this.getServerHttpRequestDecorator(exchange,outputMessage);
ServerHttpRequestDecorator decorator = new ServerHttpRequestDecorator(
exchange.getRequest()) {
@Override
public Flux<DataBuffer> getBody() {
return outputMessage.getBody();
}
};
当ServerHttpRequestDecorator构建完成之后需要在拦截器中使用如下方法替换原先的request
return chain.filter(exchange.mutate().request(decorator).build());
SpringCloudGateway中如何读取后段服务的返回数据
与上方替换request的思路一致，替换response即可
private ServerHttpResponse getServerHttpResponse(ServerWebExchange exchange) {
ServerHttpResponse originalResponse = exchange.getResponse();
DataBufferFactory bufferFactory = originalResponse.bufferFactory();
ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
@Override
public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
Flux<DataBuffer> flux = null;
if (body instanceof Mono) {
Mono<? extends DataBuffer> mono = (Mono<? extends DataBuffer>) body;
body = mono.flux();
}
if (body instanceof Flux) {
flux = (Flux<DataBuffer>) body;
return super.writeWith(flux.buffer().map(dataBuffers -> {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
dataBuffers.forEach(i -> {
byte[] array = new byte[i.readableByteCount()];
i.read(array);
DataBufferUtils.release(i);
outputStream.write(array, 0, array.length);
});
String result = outputStream.toString();
try {
if (outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
log.info("后端返回数据：{}", result);
return bufferFactory.wrap(result.getBytes());
}));
}
log.info("降级处理返回数据：{}" + body);
return super.writeWith(body);
}
};
return decoratedResponse;
}
上方是获取新的response，获取到新的之后和之前的套路一样，这样操作：
return chain.filter(exchange.mutate().request(decorator).response(decoratedResponse).build());
可能有的同学会碰到即使按照我上述的方法重写了response但是也无法读取到返回数据，这个原因可能是因为拦截器的优先级配置有问题，只需要实现Ordered接口并且重写getOrder方法，然后设置优先级小于-1即可
@Override
public int getOrder() {
return -2;
}