SpringCloud gateway request的body验证或修改
后续版本新增了以下过滤器
org.springframework.cloud.gateway.filter.headers.RemoveHopByHopHeadersFilter默认会把以下头部移除（暂不了解这做法的目的）
- connection
- keep-alive
- te
- transfer-encoding
- trailer
- proxy-authorization
- proxy-authenticate
- x-application-context
- upgrade
从而导致下面我们重写getHeaders方法时添加的transfer-encoding头部移除，导致无法解析body。
解决办法：
在yml文件中配置自定义的头部移除列表
spring:
cloud:
filter:
remove-hop-by-hop:
headers:
- connection
- keep-alive
- te
- trailer
- proxy-authorization
- proxy-authenticate
- x-application-context
- upgrade源码可见链接，且可实现动态路由配置：https://github.com/SingleTigger/SpringCloudGateway-Nacos-Demo
------------原文------------
往往业务中我们需要在网关对请求参数作修改操作（注意以下只针对带有body的请求），springcloud gateway中有提供一个
ModifyRequestBodyGatewayFilterFactory的filter，看了一下它的实现，需要指定输入类型和输出类型，比较局限。
我就参考它自己实现了一个拦截器
注意：上传文件也带有请求body，需特殊处理。
以下是主要代码
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.cloud.gateway.support.BodyInserterContext;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpHeaders;
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.BodyInserter;
import org.springframework.web.reactive.function.BodyInserters;
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;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.BiFunction;
@Component
public class CModifyRequestBodyGatewayFilterFactory extends AbstractGatewayFilterFactory {
private final List<HttpMessageReader<?>> messageReaders;
public CModifyRequestBodyGatewayFilterFactory() {
this.messageReaders = HandlerStrategies.withDefaults().messageReaders();
}
@Override
@SuppressWarnings("unchecked")
public GatewayFilter apply(Object config) {
return (exchange, chain) -> {
ServerRequest serverRequest = ServerRequest.create(exchange,
this.messageReaders);
Mono<String> modifiedBody = serverRequest.bodyToMono(String.class)
.flatMap(originalBody -> modifyBody()
.apply(exchange,Mono.just(originalBody)));
BodyInserter bodyInserter = BodyInserters.fromPublisher(modifiedBody,
String.class);
HttpHeaders headers = new HttpHeaders();
headers.putAll(exchange.getRequest().getHeaders());
headers.remove(HttpHeaders.CONTENT_LENGTH);
CachedBodyOutputMessage outputMessage = new CachedBodyOutputMessage(exchange,
headers);
return bodyInserter.insert(outputMessage, new BodyInserterContext())
.then(Mono.defer(() -> {
ServerHttpRequest decorator = decorate(exchange, headers,
outputMessage);
return chain.filter(exchange.mutate().request(decorator).build());
}));
};
}
private BiFunction<ServerWebExchange,Mono<String>,Mono<String>> modifyBody(){
return (exchange,json)-> {
AtomicReference<String> result = new AtomicReference<>();
json.subscribe(
value -> {
//value 即为请求body，在此处修改
result.set(value);
System.out.println(result.get());
},
Throwable::printStackTrace
);
return Mono.just(result.get());
};
}
private ServerHttpRequestDecorator decorate(ServerWebExchange exchange, HttpHeaders headers,
CachedBodyOutputMessage outputMessage) {
return new ServerHttpRequestDecorator(exchange.getRequest()) {
@Override
public HttpHeaders getHeaders() {
long contentLength = headers.getContentLength();
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.putAll(super.getHeaders());
if (contentLength > 0) {
httpHeaders.setContentLength(contentLength);
}
else {
httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");
}
return httpHeaders;
}
@Override
public Flux<DataBuffer> getBody() {
return outputMessage.getBody();
}
};
}
}SpringCloud Gateway获取post请求体(request body)不完整解决方案
Spring Cloud Gateway做为网关服务，通过gateway进行请求转发，在请求到达后端服务前我们可以通过filter进行一些预处理如：请求的合法性，商户验证等。
如我们在请求体中添加商户ID（merId）和商户KEY（merkey），通过此来验证请求的合法性。但是如果我们请求内容太长如转为base64的文件存储请求。此时我们在filter获取body内容就会被截取(太长的 Body 会被截断)。目前网上也没有好的解决方式。
springboot及Cloud版本如下；
| 版本 | |
|---|---|
| springboot | 2.0.8.RELEASE |
| springcloud | Finchley.SR2 |
这里提供一种解决方式，相关代码如下：
1.Requestfilter
我们采用Gateway网关的Gobalfilter，建立我们的第一个过滤器过滤所有请求。
1).通过Spring 5 的 WebFlux我们使用bodyToMono方法把响应内容转换成类 String的对象，最终得到的结果是 Mono对象
2).bodyToMono方法我们可以拿到完整的body内容，并返回String。
3).我们生成唯一的token（通过UUID），并将token放入请求的header中。
4).将获取到的完整body内容，存放到redis中。
@Component
public class RequestFilter implements GlobalFilter, Ordered {
@Autowired
private RedisClientTemplate redisClientTemplate;
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
DefaultServerRequest req = new DefaultServerRequest( exchange );
String token = UUID.randomUUID().toString();
//向headers中放入token信息
ServerHttpRequest serverHttpRequest =exchange.getRequest().mutate().header("token", token)
.build();
//将现在的request变成change对象
ServerWebExchange build = exchange.mutate().request( serverHttpRequest ).build();
return req.bodyToMono( String.class ).map( str -> {
redisClientTemplate.setObjex( "microservice:gateway:".concat( token ), 180, str );
MySlf4j.textInfo( "请求参数:{0}", str );
return str;
} ).then( chain.filter( build ) );
}
@Override
public int getOrder() {
return 0;
}
}
2.MerchantAuthFilter
建立商户认证过滤器，相关代码如下：
1).获取存储在headers中的token。
2).通过token获取我们存储在redis中的body内容(WebFlux 中不能使用阻塞的操作，目前想到的是通过这种方式实现)。
3).获取到完整的body内容后我们就可以进行相应的商户认证操作。
4).认证通过，将信息重新写入，不通过则返回异常信息。
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest serverHttpRequest = exchange.getRequest();
String token = serverHttpRequest.getHeaders().get( "token" ).get( 0 );
String bodyStr = (String) redisClientTemplate.getObj("microservice:gateway:".concat(token));
BaseReqVo baseReqVo = JsonUtil.fromJson( bodyStr, BaseReqVo.class );
try {
// 商户认证
BaseRespVo<?> baseRespVo = merchantAuthService.checkMerchantAuth( baseReqVo );
if (MicroserviceConstantParamUtils.RESULT_CODE_SUCC.equals( baseRespVo.getCode() )) {
// 若验证成功，将信息重新写入避免request信息消费后后续无法从request获取信息的问题
URI uri = serverHttpRequest.getURI();
ServerHttpRequest request = serverHttpRequest.mutate().uri(uri).build();
DataBuffer bodyDataBuffer = stringBuffer(bodyStr);
Flux<DataBuffer> bodyFlux = Flux.just(bodyDataBuffer);
request = new ServerHttpRequestDecorator(request) {
@Override
public Flux<DataBuffer> getBody() {
return bodyFlux;
}
};
// 封装request，传给下一级
return chain.filter(exchange.mutate().request(request).build());
} else {
// 若验证不成功，返回提示信息
return gatewayResponse( baseRespVo.getCode(), baseRespVo.getMessage(), exchange );
}
} catch (MicroserviceServiceException ex) {
// 若验证不成功，返回提示信息
MySlf4j.textError( "商户访问权限验证异常，异常代码:{0},异常信息:{1}, 异常{2}", ex.getCode(), ex.getMessage(), ex );
return gatewayResponse( ex.getCode(), ex.getMessage(), exchange );
} catch (Exception ex) {
MySlf4j.textError( "商户访问权限验证服务异常:{0}", LogUtil.ExceptionToString( ex ) );
return gatewayResponse( MicroserviceException.ERR_100000, "系统异常", exchange );
} finally {
redisClientTemplate.del( "microservice:gateway:".concat( token ) );
}
}
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;
}
private Mono<Void> gatewayResponse(String code, String message, ServerWebExchange exchange) {
// 若验证不成功，返回提示信息
ServerHttpResponse response = exchange.getResponse();
BaseRespVo<T> baseRespVo = ResponseUtils.responseMsg( code, message, null );
byte[] bits = JsonUtil.toJson( baseRespVo ).getBytes( StandardCharsets.UTF_8 );
DataBuffer buffer = response.bufferFactory().wrap( bits );
response.setStatusCode( HttpStatus.UNAUTHORIZED );
// 指定编码，否则在浏览器中会中文乱码
response.getHeaders().add( "Content-Type", "text/plain;charset=UTF-8" );
return response.writeWith( Mono.just( buffer ) );
}
@Override
public int getOrder() {
return 1;
}
另外我们还可以通过GlobalFilter实现请求过滤，OAUTH授权，相关代码如下：
请求方式验证过滤器（RequestAuthFilter）：
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest serverHttpRequest = exchange.getRequest();
String method = serverHttpRequest.getMethodValue();
if (!"POST".equals(method)) {
ServerHttpResponse response = exchange.getResponse();
BaseRespVo<T> baseRespVo = ResponseUtils.responseMsg(MicroserviceException.ERR_100008, "非法请求", null);
byte[] bits = JsonUtil.toJson(baseRespVo).getBytes(StandardCharsets.UTF_8);
DataBuffer buffer = response.bufferFactory().wrap(bits);
response.setStatusCode(HttpStatus.UNAUTHORIZED);
//指定编码，否则在浏览器中会中文乱码
response.getHeaders().add("Content-Type", "text/plain;charset=UTF-8");
return response.writeWith(Mono.just(buffer));
}
return chain.filter(exchange);
}OAUTH授权过滤器（OAuthSignatureFilter）：
@Value("${spring.security.user.name}")
private String securityUserName;
@Value("${spring.security.user.password}")
private String securityUserPassword;
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
String auth = securityUserName.concat(":").concat(securityUserPassword);
String encodedAuth = new sun.misc.BASE64Encoder().encode(auth.getBytes(Charset.forName("US-ASCII")));
String authHeader = "Basic " + encodedAuth;
//向headers中放授权信息
ServerHttpRequest serverHttpRequest = exchange.getRequest().mutate().header("Authorization", authHeader)
.build();
//将现在的request变成change对象
ServerWebExchange build = exchange.mutate().request(serverHttpRequest).build();
return chain.filter(build);
}
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
