SpringCloud Gateway 网关请求中body、query、header参数的获取和修改
目录
-
- 前言
- 一、请求头参数获取和修改
- 二、Query参数获取和修改
- 三、Body参数获取和修改
-
- 3.1、全局body缓存过滤器
- 3.2、获取和修改body工具类
- 3.3、获取和修改body测试
前言
最近在开发中要改造一个普通SpringBoot接口服务为SpringCloud Gateway网关服务，并且需要在网关做验签，由于我们这个服务需要对外几个第三方平台提供接口，每家请求的传参形式都不同，有将签名信息放请求头、也有将签名信息放query参数、还有直接放body中的，请求头和query参数的获取和修改都比较简单，body参数的获取和修改稍微复杂一点，本文会对SpringCloud Gateway常见几种传参数据的获取和修改做讲解。
一、请求头参数获取和修改
@Slf4j
@Component
public class HeaderGlobalFilter implements GlobalFilter , Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest request = exchange.getRequest();
// 获取请求头中的sign，因为请求头可以有多个一样的key，可能会获取到多个值所以这里返回的是List
List<String> signList = request.getHeaders().get("sign");
log.info("请求头中的signList：{}", signList);
// 获取请求头中的sign，取第一个
String signFirst = request.getHeaders().getFirst("sign");
log.info("请求头中的signFirst：{}", signFirst);
// 请求转发处理，添加新的请求头
// 因为是使用的原始的请求对象添加了新的请求头，所以下游服务能获取到请求原有请求头和新添加的请求头
ServerHttpRequest mutableReq = request.mutate()
.header("new-header", "自定义请求头")
.build();
ServerWebExchange mutableExchange = exchange.mutate().request(mutableReq).build();
return chain.filter(mutableExchange);
}
@Override
public int getOrder() {
return -2000;
}
}
二、Query参数获取和修改
@Slf4j
@Component
public class QueryParamGlobalFilter implements GlobalFilter , Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest request = exchange.getRequest();
// 获取uri对象
URI uri = request.getURI();
log.info("请求的uri = {}",uri);
String path = request.getURI().getPath();
log.info("请求的path = {}",path);
String query = request.getURI().getQuery();
log.info("请求的query = {}",query);
// 获取请求参数转换成键值对，值是一个数组
MultiValueMap<String, String> queryParams = request.getQueryParams();
log.info("获取请求参数转换成键值对 queryParams = {}",queryParams);
// 将query参数转换成键值对，值是一个字符串，hutool包的HttpUtil
Map<String, String> queryParams1 = HttpUtil.decodeParamMap(query, StandardCharsets.UTF_8);
log.info("将query参数转换成键值对 queryParams = {}",queryParams1);
// 处理uri，通过?分割，下标第0位是请求地址，第1位置是请求参数
String url = uri.toString();
String[] urlSplit = url.split("\\?");
// 拼接新的url 这里自己处理即可，我这里直接替换请求参数
String newUrl = urlSplit[0] + "?" + "name=kerwinNew&age=17";
URI newUri = null;
try {
//将编码后的 %23 替换为 ，重新用这个字符串生成 URI
newUri = new URI(newUrl.replace("%23", ""));
} catch (URISyntaxException e) {
throw new RuntimeException(e);
}
ServerHttpRequest mutableReq = request.mutate()
.uri(newUri)
.build();
ServerWebExchange mutableExchange = exchange.mutate().request(mutableReq).build();
return chain.filter(mutableExchange);
}
@Override
public int getOrder() {
return -1000;
}
}
三、Body参数获取和修改
在Gateway中通常会有一个过滤器链，而 request body 只能读取一次，也就是说，如果在过滤器A中已经读取一次，在后面的过滤器B是无法读取成功的，会抛出如下的报错
java.lang.IllegalStateException: Only one connection receive subscriber allowed.
at reactor.ipc.netty.channel.FluxReceive.startReceiver(FluxReceive.java:279)
at reactor.ipc.netty.channel.FluxReceive.lambda$subscribe$2(FluxReceive.java:129)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute$$$capture(AbstractEventExecutor.java:163)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:446)
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
at java.lang.Thread.run(Thread.java:745)
要解决这个问题需要将获取body的方法重写，进行缓存读即可，我们可以添加一个自定义CacheBodyGlobalFilter全局过滤器来进行处理，要注意的是这个过滤器优先级一定要是最高的，不然别的过滤器读取一次body数据后这里就读取不到了。
3.1、全局body缓存过滤器
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
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.MediaType;
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.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;
/**
* body 缓存过滤器
* @author Kerwin
* @date 2024/1/11
*/
@Slf4j
@Component
public class CacheBodyGlobalFilter implements GlobalFilter, Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
/**
* save request path and serviceId into gateway context
*/
ServerHttpRequest request = exchange.getRequest();
HttpHeaders headers = request.getHeaders();
// 处理参数
MediaType contentType = headers.getContentType();
long contentLength = headers.getContentLength();
if (contentLength > 0 && !MediaType.MULTIPART_FORM_DATA_VALUE.startsWith(contentType.toString())) {
if (MediaType.APPLICATION_JSON.equals(contentType) || MediaType.APPLICATION_JSON_UTF8.equals(contentType)) {
return readBody(exchange, chain);
}
}
return chain.filter(exchange);
}
/**
* default HttpMessageReader
*/
private static final List<HttpMessageReader<?>> messageReaders = HandlerStrategies.withDefaults().messageReaders();
/**
* ReadJsonBody
*
* @param exchange
* @param chain
* @return
*/
private Mono<Void> readBody(ServerWebExchange exchange, GatewayFilterChain chain) {
/**
* join the body
*/
return DataBufferUtils.join(exchange.getRequest().getBody()).flatMap(dataBuffer -> {
byte[] bytes = new byte[dataBuffer.readableByteCount()];
dataBuffer.read(bytes);
DataBufferUtils.release(dataBuffer);
Flux<DataBuffer> cachedFlux = Flux.defer(() -> {
DataBuffer buffer = exchange.getResponse().bufferFactory().wrap(bytes);
DataBufferUtils.retain(buffer);
return Mono.just(buffer);
});
/**
* repackage ServerHttpRequest
*/
ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {
@Override
public Flux<DataBuffer> getBody() {
return cachedFlux;
}
};
/**
* mutate exchage with new ServerHttpRequest
*/
ServerWebExchange mutatedExchange = exchange.mutate().request(mutatedRequest).build();
/**
* read body string with default messageReaders
*/
return ServerRequest.create(mutatedExchange, messageReaders).bodyToMono(String.class)
.doOnNext(objectValue -> {
log.debug("[GatewayContext]Read JsonBody:{}", objectValue);
}).then(chain.filter(mutatedExchange));
});
}
@Override
public int getOrder() {
return HIGHEST_PRECEDENCE;
}
}
3.2、获取和修改body工具类
public class GatewayBodyUtils {
/**
* 获取请求中的body
* @param req
* @return
*/
public static String getBody(ServerHttpRequest req) {
// 处理参数
HttpHeaders headers = req.getHeaders();
MediaType contentType = headers.getContentType();
long contentLength = headers.getContentLength();
if (contentLength > 0 && !MediaType.MULTIPART_FORM_DATA_VALUE.startsWith(contentType.toString())) {
if (MediaType.APPLICATION_JSON.equals(contentType) || MediaType.APPLICATION_JSON_UTF8.equals(contentType)) {
AtomicReference<String> requestBody = new AtomicReference<>("");
RecorderServerHttpRequestDecorator requestDecorator = new RecorderServerHttpRequestDecorator(req);
Flux<DataBuffer> body = requestDecorator.getBody();
body.subscribe(buffer -> {
CharBuffer charBuffer = StandardCharsets.UTF_8.decode(buffer.asByteBuffer());
requestBody.set(charBuffer.toString());
});
return requestBody.get();
}
}
return null;
}
/**
* 修改设置body
* @param body 不能为空
* @param exchange
* @param chain
* @return
*/
public static Mono<Void> setBody(String body,ServerWebExchange exchange, GatewayFilterChain chain){
DataBuffer bodyDataBuffer = stringBuffer(body);
Flux<DataBuffer> bodyFlux = Flux.just(bodyDataBuffer);
MediaType contentType = exchange.getRequest().getHeaders().getContentType();
ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(
exchange.getRequest()) {
@Override
public HttpHeaders getHeaders() {
HttpHeaders httpHeaders = new HttpHeaders();
int length = body.getBytes().length;
httpHeaders.putAll(super.getHeaders());
httpHeaders.remove(HttpHeaders.CONTENT_TYPE);
httpHeaders.remove(HttpHeaders.CONTENT_LENGTH);
httpHeaders.setContentLength(length);
httpHeaders.set(HttpHeaders.CONTENT_TYPE, contentType.toString());
// 设置CONTENT_TYPE
return httpHeaders;
}
@Override
public Flux<DataBuffer> getBody() {
return bodyFlux;
}
};
return chain.filter(exchange.mutate().request(mutatedRequest).build());
}
public static class RecorderServerHttpRequestDecorator extends ServerHttpRequestDecorator {
private final List<DataBuffer> dataBuffers = new ArrayList<>();
public RecorderServerHttpRequestDecorator(ServerHttpRequest delegate) {
super(delegate);
super.getBody().map(dataBuffer -> {
dataBuffers.add(dataBuffer);
return dataBuffer;
}).subscribe();
}
@Override
public Flux<DataBuffer> getBody() {
return copy();
}
private Flux<DataBuffer> copy() {
return Flux.fromIterable(dataBuffers)
.map(buf -> buf.factory().wrap(buf.asByteBuffer()));
}
}
public static 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;
}
}
3.3、获取和修改body测试
@Slf4j
@Component
public class BodyTestGlobalFilter implements GlobalFilter , Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest request = exchange.getRequest();
// 获取body
String body = GatewayBodyUtils.getBody(request);
log.info("body = {}",body);
// 修改body
JSONObject bodyJson = JSON.parseObject(body);
bodyJson.put("name","kerwin1");
bodyJson.put("age","17");
log.info("修改后body: {} ", bodyJson);
// 将新的body数据放入请求中，获取新的Mono返回
return GatewayBodyUtils.setBody(bodyJson.toJSONString(),exchange,chain);
}
@Override
public int getOrder() {
return 1;
}
}