SpringCloud 2.x学习笔记：12、Spring Cloud Gateway简单例子（Greenwich版本）

待我称王封你为后i 2022-01-10 13:57 256阅读 0赞

### 1、Spring Cloud Gateway介绍 ###

Spring Cloud Gateway是Spring Cloud官方推出的第二代网关框架，取代Zuul网关。  
Spring Cloud Gateway构建于Spring生态系统之上，包括Spring5，SpringBoot2等。它的目标是提供简单、有效的方式路由的API

Spring Cloud Gateway不能在传统的Servlet容器中工作。

请参考官方教程：  
[https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html\#\_spring\_cloud\_gateway][https_cloud.spring.io_spring-cloud-static_Greenwich.SR1_single_spring-cloud.html_spring_cloud_gateway]

### 2、简单例子演示 ###

（1）父级pom

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.cntaiping.tpa</groupId>
        <artifactId>gateway</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
            <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
        </properties>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.5.RELEASE</version>
            <relativePath/>
        </parent>
    
        <modules>
            <module>eureka-server</module>
            <module>simple-geteway</module>
        </modules>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</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>

（2）pom.xml

添加spring-cloud-starter-gateway依赖。请注意，这里千万不能有spring-boot-starter-web（父级pom.xml也没有spring-boot-starter-web），它们两个不能同时存在。  
（3）application.properties

server.port= 7010

（4）Application类

package com.cntaiping.tpa.simplegeteway;
    
    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;
    
    @SpringBootApplication
    public class SimpleGetewayApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(SimpleGetewayApplication.class, args);
        }
    
        /**
         * gateway中使用RouteLocator的Bean进行路由转发，将请求进行处理，最后转发到目标的下游服务。
         * 本例中将请求转发到http://httpbin.org:80这个地址上
         * @param builder
         * @return
         */
        @Bean
        public RouteLocator myRoutes(RouteLocatorBuilder builder) {
            return builder.routes()
                    //适用于lambda表达式的接口称之为函数型接口(只有一个抽象方法)
                    //含参Lambda表达式：(x) -> x.f()
                    //添加一个route让请求“/get”请求都转发到“http://httpbin.org/get”
                    .route(p -> p.path("/get")
                                 .filters(f -> f.addRequestHeader("flag", "HelloWorld"))
                                 .uri("http://httpbin.org:80"))
                    .build();
        }
    }

说明：

[httpbin.org][] 这个网站能测试 HTTP 请求和响应的各种信息，比如 cookie、ip、headers 和登录验证等，且支持 GET、POST 等多种方法，对 web 开发和测试很有帮助。

### 3、运行效果 ###

[http://localhost:7010/get][http_localhost_7010_get]

{
      "args": {}, 
      "headers": {
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3", 
        "Accept-Encoding": "gzip, deflate, br", 
        "Accept-Language": "zh-CN,zh;q=0.9", 
        "Flag": "HelloWorld", 
        "Forwarded": "proto=http;host=\"localhost:7010\";for=\"0:0:0:0:0:0:0:1:55191\"", 
        "Host": "httpbin.org", 
        "Upgrade-Insecure-Requests": "1", 
        "User-Agent": "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36", 
        "X-Forwarded-Host": "localhost:7010"
      }, 
      "origin": "0:0:0:0:0:0:0:1, 180.169.108.92, ::1", 
      "url": "https://localhost:7010/get"
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70]

[https_cloud.spring.io_spring-cloud-static_Greenwich.SR1_single_spring-cloud.html_spring_cloud_gateway]: https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html#_spring_cloud_gateway
[httpbin.org]: http://httpbin.org
[http_localhost_7010_get]: http://localhost:7010/get
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70]: /images/20220110/85a9e3924fc94fe79eda622a59a1eaa9.png