Spring Cloud(微服务) 概述

一、系统架构的演变

1、单体架构：所有模块都耦合在一个war包里，问题：代码耦合、迭代困难、扩展受限、技术债务

2、分布式架构：按模块把项目拆分成多个模块，问题：拆分粒度、负载均衡、远程调用不通

3、微服务：单一职能、面向服务、隔离

二、Spring Cloud概述

Spring Cloud是一套微服务开发的全家桶

spring没有重复造轮子，只是基于springboot将其他公司(Netflix)的框架组合起来

Spring Cloud= springboot + Netflix

三、Spring Cloud Alibaba概述

Spring Cloud Alibaba = springboot +Alibaba

四、Spring Cloud 和 Spring Boot的关系

Spring boot 是 Spring 的一套快速配置脚手架，可以基于spring boot 快速开发单个微服务。

Spring Cloud是一个基于SpringBoot实现的微服务开发方案；

Spring boot可以离开Spring Cloud独立使用开发项目，但是Spring Cloud离不开Springboot，属于依赖的关系

五、springboot、springcloud、springcloudalibaba版本关系？

springcloud(Hoxton） springcloudalibaba(2.2.6)

| |

springboot(2.3.2)

建议: 版本号之间相互对应

六、Nacos概述和安装

1.案例准备

1.1.创建springcloud_parent

1.1.1.pom.xml

java 复制代码

<?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>
    <groupId>com.hg</groupId>
    <artifactId>springcloud_parent</artifactId>
    <version>1.0-SNAPSHOT</version>
     <packaging>pom</packaging>
    <properties>
        <!-- 项目源码及编译输出的编码 -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <!-- 项目编译JDK版本 -->
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencyManagement>
        <dependencies>
            <!--Spring Boot-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.3.2.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring cloud Netflix-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR9</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring cloud 阿里巴巴-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.6.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

1.2.创建springcloud_common

1.2.1.pom.xml

java 复制代码

<?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_parent</artifactId>
        <groupId>com.hg</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud_common</artifactId>

</project>

1.2.2.pojo

java 复制代码

public class User {
    private Integer id;
    private String name;
    private Integer age;

    public User() {
    }

    public User(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

1.3.创建nacos_provider

1.3.1.pom.xml

java 复制代码

<?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_parent</artifactId>
        <groupId>com.hg</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>nacos_provider</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.hg</groupId>
            <artifactId>springcloud_common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

1.3.2.application.yml

server:

port: 9090

1.3.3.APP

java 复制代码

package com.hg;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ProviderApp {

    public static void main(String[] args) {
        SpringApplication.run(ProviderApp.class);
    }
}

1.3.4.service

java 复制代码

package com.hg.service;

import com.hg.pojo.User;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl implements UserService {

	@Override
	public User getUserById(Integer id) {
		return new User(id,"王粪堆",18);
	}
}

1.3.5.controller

java 复制代码

package com.hg.controller;

import com.hg.pojo.User;
import com.hg.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/provider")
public class ProviderController {
	
	@Autowired
	private UserService userService;

	@RequestMapping("/getUserById/{id}")
	public User getUserById(@PathVariable Integer id){
		return userService.getUserById(id);
	}
}

1.4.创建nacos_consumer

1.4.1.pom.xml

java 复制代码

<?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_parent</artifactId>
        <groupId>com.hg</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>nacos_consumer</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.hg</groupId>
            <artifactId>springcloud_common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

1.4.2.application.yml

server:

port: 80

1.4.3.App

java 复制代码

package com.hg;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ConsumerApp {

    public static void main(String[] args) {
        SpringApplication.run(ConsumerApp.class);
    }
}

1.4.4.config

java 复制代码

package com.hg.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class ConfigBean {

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

1.4.5.controller

java 复制代码

package com.hg.controller;

import com.hg.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
@RequestMapping(value = "/consumer")
public class ConsumerController {
	
	//访问Rest服务的客户端
	@Autowired
	private RestTemplate restTemplate;

	@RequestMapping(value="/getUserById/{id}")
	public User getUserById(@PathVariable Integer id){
		//问题：①ip、port和url硬编码   ②无法实现负载均衡
        //解决方案：调用服务Map<nacos-provider, List<127.0.0.1:9090>>
		String url = "http://127.0.0.1:9090/provider/getUserById/"+id;
		return restTemplate.getForObject(url, User.class);
	}
}

5.1.5.问题

通过上一章的操作，我们已经可以实现微服务之间的调用。但是我们把服务提供者的网络地址（ip，端口）等硬编码到了代码中，这种做法存在许多问题：

一旦服务提供者地址变化，就需要手工修改代码
一旦是多个服务提供者，无法实现负载均衡功能
一旦服务变得越来越多，人工维护调用关系困难

那么应该怎么解决呢，这时候就需要通过注册中心动态的实现服务治理。

Spring Cloud(微服务) 概述

一、系统架构的演变

二、Spring Cloud概述

三、Spring Cloud Alibaba概述

**四、**Spring Cloud 和 Spring Boot的关系

五、springboot、springcloud、springcloudalibaba版本关系？

六、Nacos概述和安装

1.案例准备

1.1.创建springcloud_parent

1.1.1.pom.xml

1.2.创建springcloud_common

1.2.1.pom.xml

1.2.2.pojo

1.3.创建nacos_provider

1.3.1.pom.xml

1.3.2.application.yml

1.3.3.APP

1.3.4.service

1.3.5.controller

1.4.创建nacos_consumer

1.4.1.pom.xml

1.4.2.application.yml

1.4.3.App

1.4.4.config

1.4.5.controller

5.1.5.问题

四、Spring Cloud 和 Spring Boot的关系