3.springcloudalibaba gateway项目搭建

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前言

前面已经完成了springcloudalibaba项目搭建，接下来搭建gateway项目，这里启动两个服务，一个是gateway服务，一个是server服务，请求从gateway到server服务。

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一、搭建gateway项目

1.1 pom配置

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

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-loadbalancer</artifactId>
        </dependency>

这里的lb需要加上，否则使用 lb://方式寻找服务，启动后请求报错如下

Service Unavailable 503

完整的pom如下

<?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>
    <groupId>com.springcloudalibaba</groupId>
    <artifactId>gateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>gateway</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>8</java.version>
        <spring-boot.version>2.6.13</spring-boot.version>
        <spring-cloud.version>2021.0.5</spring-cloud.version>
        <spring-cloud-alibaba.version>2021.0.5.0</spring-cloud-alibaba.version>
    </properties>
    <dependencies>
        <!-- SpringCloud Gateway -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-loadbalancer</artifactId>
        </dependency>

        <!-- SpringCloud Alibaba Nacos -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

        <!-- SpringCloud Alibaba Nacos Config -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
    <dependencies>
    <!-- SpringCloud 微服务 -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>${spring-cloud.version}</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>

    <!-- SpringCloud Alibaba 微服务 -->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-alibaba-dependencies</artifactId>
        <version>${spring-cloud-alibaba.version}</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>

    <!-- SpringBoot 依赖配置 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>${spring-boot.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>
                <version>2.6.0</version>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

1.2 新增配置如下

spring:
  cloud:
    gateway:
      discovery:
        locator:
          #开启服务发现功能，从注册中心获取服务列表，（nacos->服务管理->服务列表）
          #默认服务名称需要为大写，可以通过配置lower-case-service-id: true 改变这一规则
          enabled: true
      routes:
        - id: server #payment_route    #路由的ID，没有固定规则但要求唯一，建议配合服务名
          uri: lb://server         #匹配后提供服务的路由地址
          predicates:
            - Path=/server/**
            - Method=GET,POST

• -Path=/server/**： 匹配 /server/路径下的到server服务

二、新增server服务

2.1 pom配置

这要增加web模块和增加@EnableDiscoveryClient到启动类即可
server端pom配置如下

<?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>
    <groupId>com.springcloudalibaba</groupId>
    <artifactId>server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>server</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>8</java.version>
        <spring-boot.version>2.6.13</spring-boot.version>
        <spring-cloud.version>2021.0.5</spring-cloud.version>
        <spring-cloud-alibaba.version>2021.0.5.0</spring-cloud-alibaba.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- SpringCloud Alibaba Nacos -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

        <!-- SpringCloud Alibaba Nacos Config -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
    <dependencies>
    <!-- SpringCloud 微服务 -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>${spring-cloud.version}</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>

    <!-- SpringCloud Alibaba 微服务 -->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-alibaba-dependencies</artifactId>
        <version>${spring-cloud-alibaba.version}</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>

    <!-- SpringBoot 依赖配置 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>${spring-boot.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>
                <version>2.6.0</version>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

2.2新增测试接口如下

package com.springcloudalibaba.gateway.control;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Control {

    @RequestMapping(value = "/hello")
    public String index() {
        System.out.println("testname: ");
        return "testName";
    }


}

三、测试验证

3.1 分别启动两个服务，查看nacos是否注册成功

查看日志，和查看nacos上的服务，可以知道已经注册成功了。

3.2 测试

这里新增了一个hello的接口，请求地址如下
http://localhost:8080/server/hello

这个请求会先到gateway服务然后再去请求server服务，http://localhost:8080/server/hello–>
http://localhost:8081/hello,可以看到返回结果和server中的代码返回一致，测试成功。

总结

1.alibaba lb的包和gateway的一起使用，否则使用lb方式查找服务会有问题，导致请求失败。
2.- Path=/server/** 表示路径带server的路由到你指定的服务中去，真正请求的时候会去掉server这一截。