SpringBoot2 整合 SpringCloud 的 Gateway 入门实例

分手后的思念是犯贱 2023-07-08 09:12 10阅读 0赞

> **SpringCloud Gateway 是 SpringCloud 官方推出的第二代网关框架（第一代：Zuul），网关的常见功能：路由转发、权限校验和流量控制。**

### 1. 网关工程 ###

使用 RouteLocatorBuilder 的 bean 去创建路由，RouteLocatorBuilder 中可以添加各种 Predicate 和 Filter：

*  Predicate ：断言，路由转发的判断条件；
 *  Filter ：过滤器，路由请求时所经过的过滤逻辑，可用于修改请求、响应内容；

网关工程目录如下图所示：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70]  
pom.xml 如下所示，引入了 spring-cloud-starter-gateway 的依赖：

<?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>2.2.4.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.syrdbt</groupId>
        <artifactId>study</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>study</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
            <spring-cloud.version>Hoxton.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>
                <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>

启动类，GatewaStudyApplication.java ，使用 RouteLocator 进行路由转发，转发到下游业务，下游业务的地址为 http://localhost:8081 ，本网关项目的端口号为默认的 8080；断言用来判断，如果访问路径为/hello则进行过滤和转发，过滤器给转发的请求增加了一个header，header 的 key 为 Hello ，value 为 World。

package com.syrdbt.study;
    
    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.HttpHeaders;
    import org.springframework.util.RouteMatcher;
    import org.springframework.web.bind.annotation.RequestHeader;
    
    @SpringBootApplication
    public class GatewaStudyApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(GatewaStudyApplication.class, args);
        }
    
        @Bean
        public RouteLocator myRoutes(RouteLocatorBuilder builder) {
        
            return builder.routes().route(p -> p
                    // 断言，路由转发的判断条件，path 为使用过滤器修改 /hello
                    .path("/hello")
                    // 过滤器，路由请求时所经过的过滤逻辑，可用于修改请求、响应内容；
                    .filters(f -> f.addRequestHeader("Hello", "World"))
                    .uri("http://localhost:8081"))
                    .build();
        }
    }

### 2. Web 工程，网关的下游业务 ###

网关的下游业务 admin-web，工程目录如下图所示：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70 1]  
pom.xml 如下所示，引入了 spring-boot-starter-web ：

<?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>2.2.5.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.syrdbt</groupId>
        <artifactId>admin</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>admin</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</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>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

控制器，响应从网关发过来的请求，并打印了请求中key为Hello的Header，HelloController.java：

package com.syrdbt.admin.controller;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.servlet.http.HttpServletRequest;
    
    /**
     * @author syrdbt
     * @date 2020-03-03
     */
    @RestController
    public class HelloController {
        
    
        /**
         * 响应从网关发过来的请求，并打印了请求中key为Hello的Header
         */
        @RequestMapping("/hello")
        public String hello(HttpServletRequest request) {
        
            return "转发成功。请求头Hello的值" + request.getHeader("Hello");
        }
    }

启动类，正常创建即可，不过需要修改一下工程的端口号为 8081，application.properties 如下所示 ：

server.port=8081

#### 2.3 测试 ####

访问 [http://localhost:8080/hello][http_localhost_8080_hello]，请求被转发到 http://localhost:8081/hello 。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70 2]  
访问 [http://localhost:8080/hello1][http_localhost_8080_hello1]，因为不符合断言，无法进行转发，所以 404 找不到对应的页面。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70 3]

### 3. 参考文献 ###

*  [Spring Cloud Gateway 2.1.0 中文官网文档][Spring Cloud Gateway 2.1.0]
 *  [Spring Cloud Gateway 初体验][Spring Cloud Gateway]

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/2020030517475090.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky,size_16,color_FFFFFF,t_70
[http_localhost_8080_hello]: http://localhost:8080/hello
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200305175508707.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky,size_16,color_FFFFFF,t_70
[http_localhost_8080_hello1]: http://localhost:8080/hello1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20200305175600727.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NzM3OTky,size_16,color_FFFFFF,t_70
[Spring Cloud Gateway 2.1.0]: https://www.jianshu.com/p/6ff196940b67
[Spring Cloud Gateway]: https://www.fangzhipeng.com/springcloud/2018/11/06/sc-f-gateway1.html