单体进化微服务：拆分、注册、调用、网关、过滤、治理、分布式事务

基本介绍

Spring Cloud 是一个用于构建分布式系统和微服务架构的开发工具包。它提供了一系列的功能和组件，用于解决微服务架构中的常见问题，如服务注册与发现、负载均衡、配置管理、断路器等。本文将介绍如何使用 Spring Cloud 来构建一个简单的微服务架构。

服务注册与发现：
在微服务架构中，服务之间的相互调用是通过服务注册与发现来实现的。Spring Cloud 提供了 Eureka、Consul、ZooKeeper 等多种服务注册与发现的实现。我们可以选择其中一种来搭建服务注册中心，并在每个微服务启动时将自己注册到注册中心。

负载均衡：
在微服务架构中，负载均衡是将请求分发到多个服务实例上，以实现高可用和扩展性。Spring Cloud 提供了 Ribbon 作为默认的负载均衡解决方案，它可以与服务注册中心集成，自动实现负载均衡的功能。

配置管理：
在微服务架构中，配置管理可以帮助我们集中管理各个微服务的配置信息。Spring Cloud 提供了 Config Server 来实现统一的配置管理，将配置文件存储在 Git、SVN 等版本控制系统中，并通过统一的 API 接口提供给微服务使用。

断路器：
在微服务架构中，由于服务之间的相互调用，可能会出现某个服务不可用或响应超时的情况。为了保证系统的稳定性，我们可以使用断路器模式来处理这些故障。Spring Cloud 提供了 Hystrix 作为断路器的实现，可以在服务调用发生故障时进行降级或熔断处理。

生产-消费-网关

将一个服务拆分为生产、消费、网关三个微服务进行基本展示，实现了服务的拆分、注册、调用、网关、过滤，后期实现治理和分布式事务；

父依赖

<?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 http://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>2.7.12</version><relativePath/></parent><artifactId>springcloud_demo</artifactId><packaging>pom</packaging><modules><module>service_1</module><module>service_2</module><module>gate_service</module><module>common</module><module>reminder</module></modules><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><org.projectlombok.version>1.18.20</org.projectlombok.version><spring-cloud.version>2021.0.3</spring-cloud.version><spring-cloud-alibaba.version>2021.0.4.0</spring-cloud-alibaba.version><java.version>8</java.version></properties><dependencies><!-- Spring Cloud 相关依赖 --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-config</artifactId></dependency><!-- 其他 Spring Boot Starter 依赖 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency></dependencies><dependencyManagement><dependencies><!--spring cloud alibaba--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>${spring-cloud-alibaba.version}</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>${spring-cloud.version}</version><type>pom</type><scope>import</scope></dependency><!-- lombok 管理 --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>${org.projectlombok.version}</version></dependency><!--单元测试--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies></dependencyManagement></project>

生产者服务

<?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"><parent><artifactId>springcloud_demo</artifactId><groupId>org.springframework.boot</groupId><version>2.7.12</version></parent><modelVersion>4.0.0</modelVersion><artifactId>test_service</artifactId><dependencies><!--web--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--redis--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><!--单元测试--><!--nacos 服务注册发现--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency></dependencies></project>

properties配置

server.port=9092spring.application.name=service2spring.cloud.nacos.server-addr=lh:8848
spring.cloud.config.import-check.enabled=false

@SpringBootApplication
public class TestApplication {public static void main(String[] args) {SpringApplication.run(TestApplication.class, args);}}

基本生产

@RestController
@RequestMapping(path = "/hi")
public class HelloController {@Resourceprivate HelloService helloService;@RequestMapping(path = "/sy", method = RequestMethod.GET)public String sy(){// 1.根据服务名称，拉取服务的实例列表helloService.sayHi();return "service-2 say hi";}
}

消费者服务

<?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"><parent><artifactId>springcloud_demo</artifactId><groupId>org.springframework.boot</groupId><version>2.7.12</version></parent><modelVersion>4.0.0</modelVersion><artifactId>test_2</artifactId><dependencies><!--web--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--单元测试--><!--nacos 服务注册发现--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.8.11</version><scope>compile</scope></dependency><!--OpenFeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--负载均衡--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency><!--ok-http--><dependency><groupId>io.github.openfeign</groupId><artifactId>feign-okhttp</artifactId></dependency></dependencies></project>

server.port=9091spring.application.name=service1spring.cloud.nacos.server-addr=lh:8848
spring.cloud.config.import-check.enabled=falsefeign.okhttp.enabled=truelogging.level.com.com.han=debug

import com.han.config.DefaultFeignConfig;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;@EnableFeignClients(basePackages = "com.han.remote", defaultConfiguration = DefaultFeignConfig.class)
@SpringBootApplication
public class Test2Application {public static void main(String[] args) {SpringApplication.run(Test2Application.class, args);}}

配置类

import feign.Logger;
import org.springframework.context.annotation.Bean;public class DefaultFeignConfig {@Beanpublic Logger.Level feignLogLevel(){return Logger.Level.FULL;}
}``@FeignClient(value = "service2")
public interface Service2Client {@RequestMapping(method = RequestMethod.GET, path = "/hi/sy")String getHi();}```java
@Configuration
public class AppConfig {@Beanpublic RestTemplate restTemplate() {return new RestTemplate();}
}

controller

@RestController
@RequestMapping(path = "/hello")
public class HelloController {@Resourceprivate HelloService helloService;@Resourceprivate Service2Client service2Client;@RequestMapping(method = RequestMethod.GET, path = "/sy")public void sy(){// 1.根据服务名称，拉取服务的实例列表System.out.println(service2Client.getHi());helloService.sayHi();}
}

消费service

@Service
public class HelloServiceImpl implements HelloService {private final DiscoveryClient discoveryClient;@Resourceprivate RestTemplate restTemplate;@Resourceprivate Service2Client service2Client;public HelloServiceImpl(DiscoveryClient discoveryClient) {this.discoveryClient = discoveryClient;}@Overridepublic void sayHi() {System.out.println("service-1 say hi");System.out.println(service2Client.getHi());}public void sayHiByRestTemplate() {System.out.println("service-1 say hi");List<ServiceInstance> instances = discoveryClient.getInstances("service_2");// 2.负载均衡，挑选一个实例ServiceInstance instance = instances.get(RandomUtil.randomInt(instances.size()));// 3.获取实例的IP和端口ResponseEntity<String> response = restTemplate.exchange(instance.getUri() + "/hi",HttpMethod.GET,null,new ParameterizedTypeReference<String>() {},new Object());System.out.println(response.getBody());System.out.println(response);}
}

网关服务

<?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"><parent><artifactId>springcloud_demo</artifactId><groupId>org.springframework.boot</groupId><version>2.7.12</version></parent><modelVersion>4.0.0</modelVersion><artifactId>gate_service</artifactId><dependencies><!--网关--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId></dependency><!--nacos 服务注册发现--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--负载均衡--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>common</artifactId><version>2.7.12</version></dependency></dependencies></project>

server.port=9090spring.application.name=gatewayspring.cloud.nacos.server-addr=lh:8848
spring.cloud.config.import-check.enabled=falselogging.level.com.com.han=debug
logging.pattern.dateformat=HH:mm:ss:SSS
logging.file.path="logs/${spring.application.name}"spring.cloud.gateway.routes[0].id=service1
spring.cloud.gateway.routes[0].uri=lb://service1
spring.cloud.gateway.routes[0].predicates[0]=Path=/hello/**,/user/**
spring.cloud.gateway.routes[0].filters[0]=PrintAnyspring.cloud.gateway.routes[1].id=service2
spring.cloud.gateway.routes[1].uri=lb://service2
spring.cloud.gateway.routes[1].predicates[0]=Path=/hi/**spring.main.web-application-type=reactive

@SpringBootApplication
public class GateApplication {public static void main(String[] args) {SpringApplication.run(GateApplication.class, args);}
}

@Component
public class PrintAnyGatewayFilterFactory extends AbstractGatewayFilterFactory<Object> {@Overridepublic GatewayFilter apply(Object config) {return new GatewayFilter() {@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {// 获取请求ServerHttpRequest request = exchange.getRequest();// 编写过滤器逻辑System.out.println("过滤器执行了");// 放行return chain.filter(exchange);}};}
}

common服务

<?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"><parent><artifactId>springcloud_demo</artifactId><groupId>org.springframework.boot</groupId><version>2.7.12</version></parent><modelVersion>4.0.0</modelVersion><artifactId>common</artifactId><dependencies><!-- Lombok 依赖 --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.20</version><scope>provided</scope></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.8.11</version><scope>compile</scope></dependency></dependencies></project>

public class UserInfoInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {// 1.获取请求头中的用户String userInfo = request.getHeader("user-info");// 2.判断是否为空，不为空，存入Usercontextif (StrUtil.isNotBlank(userInfo)) {}// 3.放行return true;}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception{// 清除用户
//        UserContext.removeUser();}
}

package com.han.utils;import lombok.Data;@Data
public class Result<T> {//状态码private Integer code;//信息private String message;//数据private T data;//构造私有化private Result() { }//设置数据,返回对象的方法public static<T> Result<T> build(T data,Integer code,String message) {//创建Resullt对象，设置值，返回对象Result<T> result = new Result<>();//判断返回结果中是否需要数据if(data != null) {//设置数据到result对象result.setData(data);}//设置其他值result.setCode(code);result.setMessage(message);//返回设置值之后的对象return result;}//设置数据,返回对象的方法public static<T> Result<T> build(T data,ResultCodeEnum resultCodeEnum) {//创建Resullt对象，设置值，返回对象Result<T> result = new Result<>();//判断返回结果中是否需要数据if(data != null) {//设置数据到result对象result.setData(data);}//设置其他值result.setCode(resultCodeEnum.getCode());result.setMessage(resultCodeEnum.getMessage());//返回设置值之后的对象return result;}//成功的方法public static<T> Result<T> ok(T data) {Result<T> result = build(data, ResultCodeEnum.SUCCESS);return result;}//失败的方法public static<T> Result<T> fail(T data) {return build(data,ResultCodeEnum.FAIL);}public static<T> Result<T> success(T data){return build(data, ResultCodeEnum.MY_CONDITION);}}

/*** 统一返回结果状态信息类**/
@Getter
public enum ResultCodeEnum {SUCCESS(200,"成功"),FAIL(201, "失败"),MY_CONDITION(666, "JUST 6"),;private Integer code;private String message;private ResultCodeEnum(Integer code, String message) {this.code = code;this.message = message;}
}

感想

框架的引入，让我们可以只需要导包就可以完成95%的工作；
但是如何抛开框架，我们是否可以自己完成spring、springcloud这些框架的基本功能那？
技术的提升不会仅仅是使用这些api接口，我们后面会尝试自己设计一些框架去替代