SpringCloud简介

最新推荐文章于 2024-09-11 12:59:52 发布

xiang猪~

最新推荐文章于 2024-09-11 12:59:52 发布

阅读量149

点赞数

CC 4.0 BY-SA版权

分类专栏：学习内容

本文链接：https://blog.youkuaiyun.com/xfz610614/article/details/103890457

学习内容专栏收录该内容

80 篇文章

订阅专栏

本文详细介绍SpringCloud微服务架构的搭建与实践，包括服务注册与发现、负载均衡、熔断器、配置中心等核心组件的使用，以及如何构建分布式系统。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

文章目录

一、简单介绍

简介：
Spring Cloud是一系列框架的有序集合。它利用Spring Boot的开发便利性巧妙地简化了分布式系统基础设施的开发，如服务发现注册、配置中心、消息总线、负载均衡、断路器、数据监控等，都可以用Spring Boot的开发风格做到一键启动和部署。Spring Cloud并没有重复制造轮子，它只是将目前各家公司开发的比较成熟、经得起实际考验的服务框架组合起来，通过Spring Boot风格进行再封装屏蔽掉了复杂的配置和实现原理，最终给开发者留出了一套简单易懂、易部署和易维护的分布式系统开发工具包。

原有的单体项目最终会被演化成下面的样子：
在这里插入图片描述
这样的架构解决了单体项目的几点问题：

zuul网关解决了服务调用安全性的问题
服务注册与发现（注册中心）eureka解决了各层服务耦合问题，它是微服务架构的中心，有它才能将单体项目拆解成微服务架构
eureka集群解决了微服务中注册中心宕机的问题
Ribbon负载均衡及Feign消费者调用服务，减小了各微服务服务器的访问压力，默认采用了经典的轮询机制
熔断器Hystrix解决了，微服务架构中服务器雪崩现象
服务监控（单机Dashboard与集群turbine），方便运维人员查看微服务架构项目运行时，各个服务器的运行状态
服务配置中心（springcloud config），用来通过github统一管理各个微服务的配置文件（yml文件）

二、没有注册中心的简单入门案例

创建父工程microservice（父工程是一个maven项目，一般创建方式即可，父工程的主要用途是锁定pom依赖包版本。）

1.1、更改pom.xml配置

<?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.xfz</groupId>
  <artifactId>xfzmicroservice</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <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>
    <druid.version>1.1.10</druid.version>
  </properties>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Edgware.SR4</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>1.5.13.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <!--  连接池  -->
      <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>${druid.version}</version>
      </dependency>
    </dependencies>
  </dependencyManagement>


</project>

maven聚合工程的概念：
在这里插入图片描述

创建通用模块microservice-common 更改pom.xml配置

<?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.xfz</groupId>
        <artifactId>xfzmicroservice</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>microservice-common</artifactId>

    <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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2.1、排除数据源的读取 MicroserviceCommonApplication.java

package com.xfz.microservicecommon;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;

/**
 * 排除数据源的读取
 */
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})
public class MicroserviceCommonApplication {

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

}

2.2、创建entity包下的Student类建表

package com.xfz.microservicecommon.entity;

import javax.persistence.*;
import java.io.Serializable;

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 15:19
 */
@Entity
@Table(name="t_springcloud_student")
public class Student implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private Integer id;

    @Column(length=50)
    private String name;

    @Column(length=50)
    private String grade;

    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 String getGrade() {
        return grade;
    }
    public void setGrade(String grade) {
        this.grade = grade;
    }



}

创建服务提供者microservice-student-provider-1001(创建一个简单的springboot模块，这里服务提供者需要操作数据库并且被浏览器所访问。)更改pm.xml配置文件

<?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.xfz</groupId>
        <artifactId>xfzmicroservice</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <artifactId>microservice-student-provider-1001</artifactId>

    <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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
        </dependency>
        <!--  修改后立即生效，热部署  -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>springloaded</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
        <groupId>com.xfz</groupId>
        <artifactId>microservice-common</artifactId>
        <version>1.0-SNAPSHOT</version>
        <scope>compile</scope>
    </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

3.1、配置yml文件
application.yml

server:
  port: 1001
  context-path: /
spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8
    username: mybatis_ssm
    password: xiaoli
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

3.2、创建repository包下的StudentRepository类
StudentRepository

package com.xfz.microservicestudentprovider1001.repository;

import com.xfz.microservicecommon.entity.Student;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 15:53
 */
public interface StudentRepository extends JpaRepository<Student, Integer>, JpaSpecificationExecutor<Student> {

}

3.3、创建service接口
StudentService

package com.xfz.microservicestudentprovider1001.service;

import com.xfz.microservicecommon.entity.Student;

import java.util.List;

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 16:01
 */
public interface StudentService {

    public void save(Student student);

    public Student findById(Integer id);

    public List<Student> list();

    public void delete(Integer id);


}

3.4、实现service接口
StudentServiceImpl

package com.xfz.microservicestudentprovider1001.service.impl;

import com.xfz.microservicecommon.entity.Student;
import com.xfz.microservicestudentprovider1001.repository.StudentRepository;
import com.xfz.microservicestudentprovider1001.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 16:04
 */
@Service
public class StudentServiceImpl implements StudentService {

    @Autowired
    private StudentRepository studentRepository;

    @Override
    public void save(Student student) {
        studentRepository.save(student);
    }

    @Override
    public Student findById(Integer id) {
        return studentRepository.findOne(id);
    }

    @Override
    public List<Student> list() {
        return studentRepository.findAll();
    }

    @Override
    public void delete(Integer id) {
        studentRepository.delete(id);
    }

}

3.5、创建controller增删改查方法
StudentProviderController

package com.xfz.microservicestudentprovider1001.controller;

import com.xfz.microservicecommon.entity.Student;
import com.xfz.microservicestudentprovider1001.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 16:06
 */
@RestController
@RequestMapping("/student")
public class StudentProviderController {

    @Autowired
    private StudentService studentService;

    @PostMapping(value="/save")
    public boolean save(Student student){
        try{
            studentService.save(student);
            return true;
        }catch(Exception e){
            return false;
        }
    }

    @GetMapping(value="/list")
    public List<Student> list(){
        return studentService.list();
    }

    @GetMapping(value="/get/{id}")
    public Student get(@PathVariable("id") Integer id){
        return studentService.findById(id);
    }

    @GetMapping(value="/delete/{id}")
    public boolean delete(@PathVariable("id") Integer id){
        try{
            studentService.delete(id);
            return true;
        }catch(Exception e){
            return false;
        }
    }
}

创建服务消费者microservice-student-consumer-80(服务消费者主要是通过restful api来调用提供者的接口，固不需要不需要操作数据库) 更改pom配置文件

<?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.xfz</groupId>
        <artifactId>xfzmicroservice</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <artifactId>microservice-student-consumer-80</artifactId>

    <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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>
        <!--  修改后立即生效，热部署  -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>springloaded</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>

        <dependency>
            <groupId>com.xfz</groupId>
            <artifactId>microservice-common</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

4.1、在application.yml中配置端口号

server:
  port: 80
  context-path: /

4.2、排除数据源的读取
MicroserviceStudentConsumer80Application

package com.xfz.microservicestudentconsumer80;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;

@SpringBootApplication(exclude={DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})
public class MicroserviceStudentConsumer80Application {

    public static void main(String[] args) {
        SpringApplication.run(MicroserviceStudentConsumer80Application.class, args);
    }

}

4.3、创建config配置类（操作rest网络协议）
SpringCloudConfig

package com.xfz.microservicestudentconsumer80.config;

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

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 16:21
 */
@Configuration
public class SpringCloudConfig {

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

4.4、创建controller与提供者进行数据交互
StudentConsumerController

package com.xfz.microservicestudentconsumer80.controller;

import com.xfz.microservicecommon.entity.Student;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.client.RestTemplate;

import java.util.List;

/**
 * @author xfz
 * @site www.xfz.com
 * @company zking
 * @create  2020-01-08 16:24
 */
@RestController
@RequestMapping("/student")
public class StudentConsumerController {

    private final static String SERVER_IP_PORT = "http://localhost:1001";

    @Autowired
    private RestTemplate restTemplate;

    @PostMapping(value="/save")
    private boolean save(Student student){
        return restTemplate.postForObject(SERVER_IP_PORT+"/student/save", student, Boolean.class);
    }

    @GetMapping(value="/list")
    public List<Student> list(){
        return restTemplate.getForObject(SERVER_IP_PORT+"/student/list", List.class);
    }

    @GetMapping(value="/get/{id}")
    public Student get(@PathVariable("id") Integer id){
        return restTemplate.getForObject(SERVER_IP_PORT+"/student/get/"+id, Student.class);
    }

    @GetMapping(value="/delete/{id}")
    public boolean delete(@PathVariable("id") Integer id){
        try{
            restTemplate.getForObject(SERVER_IP_PORT+"/student/delete/"+id, Boolean.class);
            return true;
        }catch(Exception e){
            return false;
        }
    }
}

测试
1001的端口

80的端口

报错：

解决方法：
将生产者中的application.yml中维护表的配置删掉不再维护表，再运行就不会报错了。可能是因为之前安装mysql时没有配好，所以再运行生产者时会重复创建表所以会报此表已存在的错误。

这样就ok了

三、注册中心eureka

eureka简介
Eureka是Netflix开发的服务发现框架，本身是一个基于REST的服务，主要用于定位运行在AWS域中的中间层服务，以达到负载均衡和中间层服务故障转移的目的。SpringCloud将它集成在其子项目spring-cloud-netflix中，以实现SpringCloud的服务发现功能。
Eureka包含两个组件：Eureka Server和Eureka Client。
Eureka Server提供服务注册服务，各个节点启动后，会在Eureka Server中进行注册，这样EurekaServer中的服务注册表中将会存储所有可用服务节点的信息，服务节点的信息可以在界面中直观的看到。
Eureka Client是一个java客户端，用于简化与Eureka Server的交互，客户端同时也就别一个内置的、使用轮询(round-robin)负载算法的负载均衡器。
在应用启动后，将会向Eureka Server发送心跳,默认周期为30秒，如果Eureka Server在多个心跳周期内没有接收到某个节点的心跳，Eureka Server将会从服务注册表中把这个服务节点移除(默认90秒)。
Eureka Server之间通过复制的方式完成数据的同步，Eureka还提供了客户端缓存机制，即使所有的Eureka Server都挂掉，客户端依然可以利用缓存中的信息消费其他服务的API。综上，Eureka通过心跳检查、客户端缓存等机制，确保了系统的高可用性、灵活性和可伸缩性。

类似zookeeper，Eureka也是一个服务注册和发现组件，是SpringCloud的一个优秀子项目，不过比较坑的是，Eureka2版本已经停止更新了。但是Eureka1版本还是很稳定，功能足够用，所以还是有必要学习下。

几个常用的服务注册与发现组件比对
在这里插入图片描述
服务注册与发现原理

eureka的使用

创建module （microservice-eureka-server-2001）并修改pom文件中的配置

<?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.xfz</groupId>
        <artifactId>xfzmicroservice</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <artifactId>microservice-eureka-server-2001</artifactId>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--  修改后立即生效，热部署  -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>springloaded</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

配置application.yml文件

server:
  port: 2001
  context-path: /
eureka:
  instance:
    hostname: localhost #eureka注册中心实例名称
  client:
    register-with-eureka: false     #false 由于该应用为注册中心，所以设置为false,代表不向注册中心注册自己。
    fetch-registry: false     #false 由于注册中心的职责就是维护服务实例，它并不需要去检索服务，所以也设置为false
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/       #设置与Eureka注册中心交互的地址，查询服务和注册服务用到

在启动类中添加注解（@EnableEurekaServer）

package com.xfz.microserviceeurekaserver2001;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer
@SpringBootApplication
public class MicroserviceEurekaServer2001Application {

    public static void main(String[] args) {
        SpringApplication.run(MicroserviceEurekaServer2001Application.class, args);
    }

}

测试运行

向eureka中注册服务提供者

在生产者pom文件中添加eureka的配置

microservice-student-provider-1001

<!--添加注册中心Eureka相关配置-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-config</artifactId>
</dependency>

在生产者的xml中添加eureka配置

eureka:
  instance:
    hostname: localhost  #eureka客户端主机实例名称
    appname: microservice-student  #客户端服务名
    instance-id: microservice-student:1001 #客户端实例名称
    prefer-ip-address: true #显示IP
  client:
    service-url:
      defaultZone: http://localhost:2001/eureka   #把服务注册到eureka注册中心

在启动类中添加注释（@EnableEurekaClient）

package com.xfz.microservicestudentprovider1001;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EntityScan("com.xfz.*.*")
@EnableEurekaClient
@SpringBootApplication
public class MicroserviceStudentProvider1001Application {

    public static void main(String[] args) {
        SpringApplication.run(MicroserviceStudentProvider1001Application.class, args);
    }

}

测试
点击实例状态如下
解决方案
6.1、首先在服务提供者项目pom.xml里加入actuator监控依赖：

<!-- actuator监控引入 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

6.2、最后服务提供者项目application.yml加上info配置：

info:
  groupId: com.xfz
  artifactId: microservice-student-provider-1001
  version: 1.0-SNAPSHOT
  userName: http://xfz.com
  phone: 123456

6.3、显示效果
在这里插入图片描述