spring cloud 入门

学习目标：

学习spring cloud项目快速搭建方法，学习nacos注册中心使用，实现两个服务间的调用

学习内容：

一、Spring Cloud介绍

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Spring 以 Bean（对象）为中心，提供 IOC、AOP 等功能。
Spring Boot 以 Application（应用）为中心，提供自动配置、监控等功能。
Spring Cloud 以 Service（服务）为中心，提供服务的注册与发现、服务的调用与负载均衡等功能。

Spring Cloud 官方对自己的简短介绍：基于 Spring 构建分布式系统的工具集，简称“Spring 全家桶”。
Spring Cloud 官方对功能点的介绍：
【配置中心】Distributed/versioned configuration
【注册中心】Service registration and discovery
【API 网关】Routing
【服务调用】Service-to-service calls
【负载均衡】Load balancing
【服务容错】Circuit Breakers
【分布式消息】Distributed messaging
SpringCloudAlibaba介绍：Spring Cloud 是分布式微服务架构的一站式解决方案，它提供了一套简单易用的编程模型，使我们能在 Spring Boot 的基础上轻松地实现微服务系统的构建。 Spring Cloud 提供以微服务为核心的分布式系统构建标准。
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Spring Cloud 提供了非常强大的功能，但是它并不提供所有的实现，而是通过 Spring Cloud Common 子项目，定义了统一的抽象 API。而后，不同厂商结合其自身的中间件，提供自己的 Spring Cloud 套件，Spring Cloud 官方、Netflix、Alibaba 三者整理成如下表格
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二、Spring Cloud项目快速搭建

2.1技术选型

SpringCloud版本与SpringBoot对应关系：Spring Cloud 官方
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SpringCloudAlibaba对应关系：版本发布说明 | Spring Cloud Alibaba

由于主机jdk安装的是1.8因此选用如下技术栈：
基础版本：
<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>
技术选型：
注册中心：spring-cloud-starter-alibaba-nacos-discovery
配置中心：spring-cloud-starter-alibaba-nacos-config
服务调用：spring-cloud-starter-openfeign
负载均衡：spring-cloud-loadbalancer
API网关：spring-cloud-starter-gateway

2.2创建SpringCloud父工程

2.2.1 创建maven工程

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2.2.2 修改pom文件，指定依赖版本

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.example</groupId>
    <artifactId>cloudDemo</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>gatewey</module>
        <module>feignconsumer</module>
        <module>feignprovide</module>
    </modules>
    <name>cloudDemo Maven Webapp</name>
    <url>http://maven.apache.org</url>

    <!-- 统一管理jar包版本 -->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>

        <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>
        <lombok.version>1.18.28</lombok.version>
    </properties>

    <!-- 子模块继承之后，提供作用：锁定版本+子modlue不用写groupId和version  -->
    <dependencyManagement>
        <dependencies>

            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <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>

            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
                <optional>true</optional>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring.boot.version}</version>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>

            </plugin>
        </plugins>
    </build>
</project>

2.3创建网关demo

2.3.1 网关的功能

性能：API高可用，负载均衡，容错机制。
安全：权限身份认证、脱敏，流量清洗，后端签名（保证全链路可信调用）,黑名单（非法调用的限制）。
日志：日志记录（spainid,traceid）一旦涉及分布式，全链路跟踪必不可少。
缓存：数据缓存。
监控：记录请求响应数据，api耗时分析，性能监控。
限流：流量控制，错峰流控，可以定义多种限流规则。
灰度：线上灰度部署，可以减小风险。
路由：动态路由规则

2.3.2 新建gateway子模块

1、创建maven项目，修改pom.xml文件

<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/maven-v4_0_0.xsd">
    <parent>
        <artifactId>cloudDemo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>gatewey</artifactId>
    <packaging>war</packaging>
    <name>gatewey Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <dependencies>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
            <exclusions>
                <!-- 排除web依赖-->
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-web</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

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

        <!-- nacos 客户端 作为 注册与发现-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!-- nacos 配置中心 -->
        <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-loadbalancer</artifactId>
        </dependency>

    </dependencies>
    <build>
        <finalName>gatewey</finalName>
    </build>
</project>

2、添加启动类GatewayApplication.java

package cloud.demo.gateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.ComponentScan;

/**
 * @ClassName GatewayApplication
 * @Description TODO
 * @Author c_see
 * @Date 2024/2/29 11:22
 * @Version 1.0
 **/
@SpringBootApplication
@EnableDiscoveryClient
@ComponentScan(basePackages = {"cloud.demo"})
public class GatewayApplication {


    public static void main(String[] args) {
        SpringApplication.run(GatewayApplication.class, args);
        System.out.println("网关启动成功");
    }
}

3、添加配置文件application.yaml

server:
  port: 8081
spring:
  profiles:
    active: dev
  application:
    name: gateway-demo
  cloud:
    gateway:
      discovery:
        locator:
          # 是否与服务发现组件进行结合，通过 serviceId 转发到具体的服务实例。默认为false
          enabled: true
          lower-case-service-id: true #使用小写service-id
    nacos:
      username: nacos
      password: nacos
      config:
        server-addr: 127.0.0.1:8848
        namespace: public
  
      discovery:
        server-addr: 127.0.0.1:8848
        namespace: public

  config:
    import:
      - optional:nacos:gateway-demo.yml?refreshEnabled=true

4、在nacos中添加配置gateway-demo.yml，配置动态路由


spring:
  cloud:
    gateway:
      routes: # 网关路由配置
        # 路由id,自定义,只要唯一即可
        - id: feignconsumer 
          # 目标服务地址（uri：地址，请求转发后的地址）
          # uri: http://127.0.0.1:8081 路由的目标地址http 就是固定地址，uri的协议为lb，表示启用Gateway的负载均衡功能。
          # 路由的目标地址lb就是负载均衡,后面跟服务名称
          uri: lb://feign-consumer
          # 路由断言，也就是判断请求是否符合路由规则的条件;转发地址格式uri/archive
          predicates: 
          # 这个是按照路径匹配，只要以 /user/ 开头就符合要求
            - Path=/user/** 
          #fitters:
          #  - RewritePath=/user/?(?<segment>.*),/$\{segment}
        - id: feignprovide
          uri: lb://feign-provide
          predicates:
            - Path=/provide/**
            # 在这个时间之后的请求才会被转发
            #- After=2031-04-13T15:14:47.433+08:00[Asia/Shanghai]

2.4 创建服务提供者

1、创建feign-provide子模块，修改pom.xml

<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/maven-v4_0_0.xsd">
    <parent>
        <artifactId>cloudDemo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>feignprovide</artifactId>
    <packaging>war</packaging>
    <name>feignprovide Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <!-- feign -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-loadbalancer</artifactId>
        </dependency>
    </dependencies>
    <build>
        <finalName>feignprovide</finalName>
    </build>
</project>

2.创建启动类ProvideApplication

package cloud.demo.provide;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

/**
 * @ClassName ProvideApplication
 * @Description TODO
 * @Author c_see
 * @Date 2024/2/29 14:28
 * @Version 1.0
 **/
@EnableDiscoveryClient
@SpringBootApplication
public class ProvideApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProvideApplication.class, args);
        System.out.println("ProvideApplication 启动成功");
    }
}

3.创建配置文件application.yaml

server:
  port: 8082
spring:
  profiles:
    active: dev
  application:
    name: feign-provide
  cloud:
    nacos:
      username: nacos
      password: nacos
      config:
        server-addr: 127.0.0.1:8848
        namespace: public

      discovery:
        server-addr: 127.0.0.1:8848
        namespace: public

4、创建测试接口类UserProvideController

package cloud.demo.provide.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("user")
public class UserProvideController {

    @Value("${server.port}")
    private String port;

    /**
     * 通过用户ID获取用户
     * @param userId
     * @return
     */
    @GetMapping("/getUser/{userId}")
    public String getUser(@PathVariable("userId") String userId){

        return String.format("【%s-服务提供者】：%s", port, userId);
    }


}

2.5 创建消费者子模块

1.创建feign-consumer子模块，修改pom.xml

<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/maven-v4_0_0.xsd">
    <parent>
        <artifactId>cloudDemo</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>feignconsumer</artifactId>
    <packaging>war</packaging>
    <name>feignconsumer Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <!-- feign -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

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

    </dependencies>
    <build>
        <finalName>feignconsumer</finalName>
    </build>
</project>

2. 创建feign客户端UserClient

package cloud.demo.consumer.client;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

/**
 * 有关消费者client,配置需要调用服务者的名字
 */
@FeignClient(name = "feign-provide") //对应的要调用提供者服务名spring.application.name
public interface UserClient {

    /**
     * 通过用户id获取用户
     * @param userId
     * @return
     */
    @GetMapping("/user/getUser/{userId}")//对应要调用提供者的controller
    String getUser(@PathVariable("userId") String userId);
}

3.创建启动类ConsumerApplication

package cloud.demo.consumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

/**
 * @ClassName ConsumerApplication
 * @Description TODO
 * @Author c_see
 * @Date 2024/2/29 14:10
 * @Version 1.0
 **/
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients(basePackages = "cloud.demo.consumer.client")
public class ConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConsumerApplication.class, args);
        System.out.println("ConsumerApplication 启动成功");
    }
}

4.创建配置文件application.yaml

server:
  port: 8083
spring:
  profiles:
    active: dev
  application:
    name: feign-consumer
  cloud:
    nacos:
      username: nacos
      password: nacos
      config:
        server-addr: 127.0.0.1:8848
        file-extension: yml
      discovery:
        server-addr: 127.0.0.1:8848

4.创建测试接口类FeignConsumerController

package cloud.demo.consumer.controller;

import cloud.demo.consumer.client.UserClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * 平台controller业务逻辑，引入client出发消费者调用提供者
 */
@RestController
@RequestMapping("user")
public class FeignConsumerController {

    @Value("${server.port}")
    private String port;

    @Resource
    private UserClient userClient;

    /**
     * 通过用户ID获取用户
     * @param userId
     * @return
     */
    @GetMapping("/getUserInfo/{userId}")
    public String getUserInfo(@PathVariable("userId") String userId){

        String user = userClient.getUser(userId);
        return String.format("【%s-Demo消费者】：调用Feign接口返回值 %s", port, user);
    }

}