SpringCloud GateWay网关无法返回信息数据与Expect: 100-continue

最近做支付项目从大的项目独立出来所以专门搭建了一个网关。上网查了些资料都说SpringCloud GateWay性能比较好所以就搭建了，其中踩了不了坑，包括JWT权限验证、限流等。但这些搭建都算比较容易网上已经有了很多教程。踩的最坑花时间最长的就是支付交易后，接收交易通知服务处理过后返回响应数据接收不到。下面做的仅做简单模拟。

1.搭建一个简单网关

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.gate</groupId>
    <artifactId>gateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>gateway</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>



    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>27.1-jre</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

响应拦截，打印响应信息

package com.gate;

import lombok.extern.slf4j.Slf4j;
import org.omg.CORBA.PUBLIC_MEMBER;
import org.reactivestreams.Publisher;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.DefaultDataBufferFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

@Component
@Slf4j
public class ResponseFilter implements GlobalFilter, Ordered {


    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //获取返货response
        ServerHttpResponse originalResponse = exchange.getResponse();
        DataBufferFactory bufferFactory = originalResponse.bufferFactory();

        HttpStatus statusCode = originalResponse.getStatusCode();

        if (statusCode ==HttpStatus.OK){
            ServerHttpResponseDecorator decorator = new ServerHttpResponseDecorator(originalResponse){

                @Override
                public Mono<Void> writeWith(Publisher<? extends DataBuffer> body){
                    Flux<? extends DataBuffer> fluxBody = Flux.from(body);
                    return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
                        DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
                        DataBuffer join = dataBufferFactory.join(dataBuffers);
                        byte[] content = new byte[join.readableByteCount()];
                        join.read(content);

                        DataBufferUtils.release(join);
                        String responseData = new String(content, StandardCharsets.UTF_8);
                        //responseData就是下游系统返回的内容,可以查看修改
                        log.info("响应内容:{}", responseData);
                        byte[] uppedContent = new String(responseData.getBytes(), Charset.forName("UTF-8")).getBytes();
                        return bufferFactory.wrap(uppedContent);

                    }));
                }
            };
            return chain.filter(exchange.mutate().response(decorator).build());
        }
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return -2;
    }
}

application.yml配置

server:
  port: 8080
spring:
  application:
    name: api-gateway
  cloud:
    gateway:
      routes:
        - id: add_request_parameter_route
          uri: lb://producer
          predicates:
            - Path=/producer/**
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/

2.注册中心比较简单可以自己自行搭建

3.搭建一个服务提供者

@RestController
@RequestMapping("/producer")
public class TestController {

    @RequestMapping("/foo")
    public String foo(String foo) {
        return "hello "+foo+"!";
    }

    @PostMapping("/test")
    public Object test(@RequestParam Map<String,String> paramsMap){
        System.out.println(paramsMap);

        return paramsMap;
    }




}

下面用postMan请求网关。