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

<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>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.7.12version>
        <relativePath/>
    parent>


    <artifactId>springcloud_demoartifactId>
    <packaging>pompackaging>

    <modules>
        <module>service_1module>
        <module>service_2module>

        <module>gate_servicemodule>
        <module>commonmodule>
        <module>remindermodule>
    modules>

    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
        <org.projectlombok.version>1.18.20org.projectlombok.version>
        <spring-cloud.version>2021.0.3spring-cloud.version>
        <spring-cloud-alibaba.version>2021.0.4.0spring-cloud-alibaba.version>
        <java.version>8java.version>
    properties>

    <dependencies>
        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-configartifactId>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

    dependencies>

    <dependencyManagement>
        <dependencies>
            
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-alibaba-dependenciesartifactId>
                <version>${spring-cloud-alibaba.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>

            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>${spring-cloud.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>

            
            <dependency>
                <groupId>org.projectlombokgroupId>
                <artifactId>lombokartifactId>
                <version>${org.projectlombok.version}version>
            dependency>
            
            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-starter-testartifactId>
                <scope>testscope>
            dependency>

        dependencies>
    dependencyManagement>



project>
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生产者服务

<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_demoartifactId>
        <groupId>org.springframework.bootgroupId>
        <version>2.7.12version>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>test_serviceartifactId>
    <dependencies>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-data-redisartifactId>
        dependency>

        

        
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
        dependency>


    dependencies>


project>
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properties配置

server.port=9092

spring.application.name=service2

spring.cloud.nacos.server-addr=lh:8848
spring.cloud.config.import-check.enabled=false


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

}

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基本生产

@RestController
@RequestMapping(path = "/hi")
public class HelloController {

    @Resource
    private 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";
    }
}

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消费者服务

<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_demoartifactId>
        <groupId>org.springframework.bootgroupId>
        <version>2.7.12version>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>test_2artifactId>

    <dependencies>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        

        
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
        dependency>
        <dependency>
            <groupId>cn.hutoolgroupId>
            <artifactId>hutool-allartifactId>
            <version>5.8.11version>
            <scope>compilescope>
        dependency>


        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-openfeignartifactId>
        dependency>
        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-loadbalancerartifactId>
        dependency>
        
        <dependency>
            <groupId>io.github.openfeigngroupId>
            <artifactId>feign-okhttpartifactId>
        dependency>

    dependencies>

project>
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server.port=9091

spring.application.name=service1

spring.cloud.nacos.server-addr=lh:8848
spring.cloud.config.import-check.enabled=false


feign.okhttp.enabled=true

logging.level.com.com.han=debug


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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);
    }

}

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配置类

import feign.Logger;
import org.springframework.context.annotation.Bean;

public class DefaultFeignConfig {

    @Bean
    public 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 {

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

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controller

@RestController
@RequestMapping(path = "/hello")
public class HelloController {

    @Resource
    private HelloService helloService;

    @Resource
    private 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();
    }
}

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消费service

@Service
public class HelloServiceImpl implements HelloService {

    private final DiscoveryClient discoveryClient;

    @Resource
    private RestTemplate restTemplate;

    @Resource
    private Service2Client service2Client;

    public HelloServiceImpl(DiscoveryClient discoveryClient) {
        this.discoveryClient = discoveryClient;
    }

    @Override
    public 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);
    }
}

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网关服务

<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_demoartifactId>
        <groupId>org.springframework.bootgroupId>
        <version>2.7.12version>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>gate_serviceartifactId>
    <dependencies>
        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-gatewayartifactId>
        dependency>

        
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
        dependency>


        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-loadbalancerartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>commonartifactId>
            <version>2.7.12version>
        dependency>
    dependencies>

project>
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server.port=9090

spring.application.name=gateway

spring.cloud.nacos.server-addr=lh:8848
spring.cloud.config.import-check.enabled=false

logging.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]=PrintAny



spring.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



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

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@Component
public class PrintAnyGatewayFilterFactory extends AbstractGatewayFilterFactory<Object> {
    @Override
    public GatewayFilter apply(Object config) {
        return new GatewayFilter() {
            @Override
            public 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);
            }
        };
    }
}




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common服务

<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_demoartifactId>
        <groupId>org.springframework.bootgroupId>
        <version>2.7.12version>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>commonartifactId>


    <dependencies>
        
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <version>1.18.20version>
            <scope>providedscope>
        dependency>

        <dependency>
            <groupId>cn.hutoolgroupId>
            <artifactId>hutool-allartifactId>
            <version>5.8.11version>
            <scope>compilescope>
        dependency>
    dependencies>

project>
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public class UserInfoInterceptor implements HandlerInterceptor {

    @Override
    public 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Usercontext
        if (StrUtil.isNotBlank(userInfo)) {


        }
        // 3.放行
        return true;
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception{

        // 清除用户
//        UserContext.removeUser();
    }
}

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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);
    }


}

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/**
 * 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;
    }
}

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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