Spring Cloud Gateway-简单路由或后备功能不起作用

问题描述

我是Spring Cloud Gateway实施的新手。仅通过尝试一个简单的教程，代码似乎无法正常工作。请参阅以下步骤和我完成的代码。

使用spring初始化程序创建一个网关项目

Pom.xml

<?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>2.3.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.SR7</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </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>

添加了简单路线。 -> ServerCodecConfigurer出错。
解决了错误，运行了项目。

Application.java

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.http.codec.ServerCodecConfigurer;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class,args);
    }
    
    @Bean
    public ServerCodecConfigurer serverCodecConfigurer() {
        return ServerCodecConfigurer.create();
    }
    
    @Bean
    public RouteLocator myRoutes(RouteLocatorBuilder builder) {
        return builder.routes()
                .route(p -> p
                        .path("/get")
                        .filters(f -> f.addRequestHeader("Hello","Value"))
                        .uri("http://httpbin.org:80"))
                .build();
    }

}

运行命令：$curl --dump-header - http://localhost:9000/get

HTTP/1.1 404
vary: Origin
vary: Access-Control-Request-Method
vary: Access-Control-Request-Headers
Content-Type: application/json
transfer-encoding: chunked
Date: Tue,18 Aug 2020 21:16:39 GMT

{"timestamp":"2020-08-18T21:16:39.260+00:00","status":404,"error":"Not Found","message":"","path":"/get"}

预期的响应

HTTP/1.1 200 OK
Date: Wed,19 Aug 2020 08:21:29 GMT
Content-Type: application/json
Content-Length: 254
Connection: keep-alive
Server: gunicorn/19.9.0
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true

{
  "args": {},"headers": {
    "Accept": "*/*","Host": "httpbin.org","User-Agent": "curl/7.55.1","X-Amzn-Trace-Id": "Root=1-5f3ce109-63eb231a030488be4168fc7e"
  },"origin": "0.0.0.0","url": "http://httpbin.org/get"
}

使用Greenwich.SR2云版本和其他项目，该路由似乎有效，但Hystrix仍然无效。使用以下示例项目： https://github.com/spring-guides/gs-gateway

任何有关使用Hystrix和Eureka实施云网关的帮助都会有所帮助。尝试了很多组合，但它似乎仍然不起作用。

解决方法

从start.spring.io构建一个简单的网关，并且您的mRoutes() bean工作正常，我得到了预期的响应。 hystrix-dashboard是必需的servlet，当我添加它时，您会遇到ServerCodecConfigurer的问题。

如果您查看日志，将会看到：

2020-08-19 16:36:58.943  WARN 157108 --- [           main] GatewayClassPathWarningAutoConfiguration : 

**********************************************************

Spring MVC found on classpath,which is incompatible with Spring Cloud Gateway at this time. Please remove spring-boot-starter-web dependency.

**********************************************************

删除不兼容的spring-cloud-starter-netflix-hystrix-dashboard依赖项。

java java maven spring-boot spring-cloud-gateway spring-cloud-netflix