Spring Cloud Alibaba 01_使用 nacos 实现服务治理

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**Spring Cloud Alibaba 01\_使用 nacos 实现服务治理**

*  **创建 spring Boot 父工程 springcloudalibabademo，修改版本为 2.3.0.RELEASE**

<?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>2.3.0.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.blu</groupId>
        <artifactId>springcloudalibabademo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>springcloudalibabademo</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-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </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>Hoxton.SR3</version>
                </dependency>
                <dependency>
                    <groupId>com.alibaba.cloud</groupId>
                    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                    <version>2.2.1.RELEASE</version>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

--------------------

*  **服务治理（服务注册和服务发现）**

**服务注册**

**2.2.1.RELEASE 版本的 spring-cloud-alibaba 对应的 nacos 版本为 1.2.1**

**下载nacos 1.2.1：[https://github.com/alibaba/nacos/releases/tag/1.2.1][https_github.com_alibaba_nacos_releases_tag_1.2.1]**

**解压启动后，访问nacos（初始用户名和密码都是nacos）：[http://localhost:8848/nacos/index.html][http_localhost_8848_nacos_index.html]**

--------------------

**创建 spring Boot 子模块 provider**

**将子模块 provider 的 parent 标签修改为父工程信息**

**添加 nacos 的依赖，版本（2.2.1.RELEASE）与父工程的 spring-cloud-alibaba 版本一致：**

<parent>
    	<groupId>com.blu</groupId>
    	<artifactId>springcloudalibabademo</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    </parent>

<dependency>
    	<groupId>com.alibaba.cloud</groupId>
    	<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    	<version>2.2.1.RELEASE</version>
    </dependency>

<?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>com.blu</groupId>
            <artifactId>springcloudalibabademo</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
        <groupId>com.blu</groupId>
        <artifactId>provider</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>provider</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
    
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
                <version>2.2.1.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</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>

**编写 application.yml 配置文件：**

spring:
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848
      application:
        name: provider
    
    server:
      port: 8080

**ProviderController**

package com.blu.controller;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class ProviderController { 
    
        @Value("${server.port}")
        private String port;
    
        @GetMapping("/index")
        public String index(){ 
            return this.port;
        }
    
    }

**启动，服务注册成功：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center]

**修改端口号，启动3个实例**

**如果出现以下窗口，在Run/Debug Configurations 中勾选 Allow parallel on 即可启动多个实例：**

![在这里插入图片描述][20201019155140521.png_pic_left]

**实例数变为了3：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center 1]

**点击详情可查看和配置集群信息：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center 2]

--------------------

**服务发现**

**创建 spring Boot 子模块 consumer**

**修改 parent 标签并添加 nacos 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>com.blu</groupId>
            <artifactId>springcloudalibabademo</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
        <groupId>com.blu</groupId>
        <artifactId>consumer</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>consumer</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
                <version>2.2.1.RELEASE</version>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</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>

**将端口设置为 8100 :**

server:
      port: 8100

**ConsumerConfiguration（注入RestTemplate）：**

package com.blu.configuration;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.client.RestTemplate;
    
    @Configuration
    public class ConsumerConfiguration { 
    
        @Bean
        public RestTemplate restTemplate(){ 
            return new RestTemplate();
        }
    
    }

**ConsumerController ：**

package com.blu.controller;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cloud.client.ServiceInstance;
    import org.springframework.cloud.client.discovery.DiscoveryClient;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    import java.util.List;
    import java.util.concurrent.ThreadLocalRandom;
    
    @RestController
    public class ConsumerController { 
    
        @Autowired
        private DiscoveryClient discoveryClient;
    
        //RestTemplate不会自动装载，不能直接用，需要在配置类中配置
        @Autowired
        private RestTemplate restTemplate;
    
        @GetMapping("/instances")
        public List<ServiceInstance> instances(){ 
            List<ServiceInstance> provider = discoveryClient.getInstances("provider");
            return provider;
        }
    
        @GetMapping("index")
        public String index(){ 
            //调用provider服务的index方法
            //1. 找到provider实例
            List<ServiceInstance> list = discoveryClient.getInstances("provider");
            //2. 产生随机数0，1，2
            int index = ThreadLocalRandom.current().nextInt(list.size());
            //3. 根据随机数0，1，2随机获取服务的3个实例
            ServiceInstance serviceInstance = list.get(index);
            //4. 获取服务的uri: localhost:8080
            String uri = serviceInstance.getUri().toString();
            //5. 拼接url: localhost:8080/index
            String url = uri + "/index";
            //使用RestTemplate调用
            String result = restTemplate.getForObject(url, String.class);
            return "调用的端口为："+ result;
    
        }
    
    }

**启动访问：[http://localhost:8100/instances][http_localhost_8100_instances]**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center 3]

**访问：[http://localhost:8100/index][http_localhost_8100_index]**

**这里访问的服务实例是随机的**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_left]

[https_github.com_alibaba_nacos_releases_tag_1.2.1]: https://github.com/alibaba/nacos/releases/tag/1.2.1
[http_localhost_8848_nacos_index.html]: http://localhost:8848/nacos/index.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center]: /images/20221123/d79d845268e74acb9087e8c281880234.png
[20201019155140521.png_pic_left]: /images/20221123/3861472ab8e4419db27520760f34220f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center 1]: /images/20221123/1e8bf1e34ed840a48c1c1bff08497b76.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center 2]: /images/20221123/e806035d38a34cb790dcb400b2f3ed2b.png
[http_localhost_8100_instances]: http://localhost:8100/instances
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_center 3]: /images/20221123/72ba1991340546bca5beb54bdeb4cca7.png
[http_localhost_8100_index]: http://localhost:8100/index
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVV8xMTE_size_16_color_FFFFFF_t_70_pic_left]: /images/20221123/8b63a3e8b94f48aea89e6085a9b680d1.png