springcloud 入门

主宰稳场 提交于 2019-12-06 14:29:47

 

1、springcloud简介

2、注册中心eureka

 

 

Springcloud简介

 

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。

详细介绍: https://baike.so.com/doc/25751000-26884657.html

 

配套参考资料:

https://projects.spring.io/spring-cloud/    springcloud项目官方主页

 

https://springcloud.cc/  springcloud中文网 有很详细的翻译文档 

 

http://springcloud.cn/  springcloud中文论坛 

 

 

 

 

Springcloud版本pom文件生成可借助网站:

https://start.spring.io/

 

 

 

原有的单体项目最终会被演化成下面

 

 

 

 

 

这样的架构解决了单体项目几点问题:

1、zuul网关解决了服务调用安全性的问题

2、服务注册与发现(注册中心)eureka解决了各层服务耦合问题,它是微服务架构的核心,有它才能将单体项目拆解成微服务架构

3、Eureka集群解决了微服务中,注册中心宕机产生的问题

 

4、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

 

5、熔断器Hystrix解决了,微服务架构中服务器雪崩现象

 

6、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

 

7、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)

 

 

 

详情查阅可见中的images文件夹

 

 

入门案例

 

最简单的微服务架构会有四个工程

 

父工程:spring cloud

 

通用模块(M):microservice-common

 

服务提供者(C):microservice-student-provider-1001

 

服务消费者(C):microservice-student-consumer-80

 

微服务架构注意点:

1、springboot、springcloud版本在父工程定义;

2、由于通用模块无需操作数据库,springboot启动默认会读取数据库,所以得添加以下注解 @SpringBootApplication(exclude={DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})

3分布式jpa需要在启动类上添加@EntityScan("com.javaxl.*.*")

4消费者需要添加配置类获取org.springframework.web.client.RestTemplatespringcloud底层是通过RestTemplate来调用提供者的服务的。

 

传统项目拆分成微服务架构图

 

 

 

 

 

 

创建父工程spring cloud

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。由于springcloud2X停止更新,这里我们采用稳定的低版本,配套的springboot版本为1x版本。

 

pom配置如下(父工程为maven工程,子工程为springboot工程

<?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.hmc</groupId>
  <artifactId>springcloud</artifactId>
  <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

  <name>springcloud</name>
  <!-- FIXME change it to the project's website -->


  <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>
    <!--锁定pom依赖jar包,但不实际引入-->
      <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>

 

 

创建通用模块microservice-common

通用模块主要存放实体类、工具包等被整个微服务框架所使用的代码。创建一个简单的springboot模块即可。相关代码如下

pom.xml

 

<?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.hmc</groupId>
        <artifactId>springcloud</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</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
    </dependencies>

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

</project>

 

 

MicroserviceCommonApplication.java 

package com.hmc.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;

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

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

}

 

 

Student.java 

package com.hmc.microservicecommon.entity;

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

@Entity
@Table(name="t_springboot_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,固需要添加相关配置如下

pom.xml

<?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.hmc</groupId>
        <artifactId>springcloud</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.hmc</groupId>
            <artifactId>microservice-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!--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>
        <!-- actuator监控引入 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

 

 

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/book?useUnicode=true&characterEncoding=utf8
    username: root
    password: 123
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

MicroserviceStudentProvider1001Application.java 

package com.hmc.microservicestudentprovider1001;

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

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

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

}

 

StudentRepository.java 

package com.hmc.microservicestudentprovider1001.repository;

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

public interface StudentRepository extends JpaRepository<Student, Integer>, JpaSpecificationExecutor<Student> {
 
}

 

 

StudentService.java 

package com.hmc.microservicestudentprovider1001.service;

import com.javaxl.microservicecommon.entity.Student;

import java.util.List;

public interface StudentService {
 
    public void save(Student student);
     
    public Student findById(Integer id);
     
    public List<Student> list();
     
    public void delete(Integer id);
     
     
}

 

 

 

StudentServiceImpl.java 

package com.hmc.microservicestudentprovider1001.service.impl;

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

import java.util.List;

@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);
    }

}

 

 

 

StudentProviderController.java 

package com.hmc.microservicestudentprovider1001.controller;

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

import java.util.List;

@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,相关配置如下

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

    <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.hmc</groupId>
            <artifactId>microservice-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>com.hmc</groupId>
            <artifactId>microservice-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

 

 

application.yml 

server:
  port: 80
  context-path: /

 

 

MicroserviceStudentConsumer80Application.java 

package com.hmc.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);
    }

}

 

 

SpringCloudConfig.java 

package com.hmc.microservicestudentconsumer80.config;


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

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

 

 

StudentConsumerController.java 

package com.hmc.microservicestudentconsumer80.controller;


import com.hmc.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;

@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;
        }
    }
}

 

 

关于如何配置RunDashboard

https://www.cnblogs.com/yangtianle/p/8818255.html

 

成功结果图如下

 

 

 

 

 

 

 

 

初识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。

 

但是这里有几个常用的服务注册与发现组件比对;

 

 

 

 

 

 

服务注册与发现原理。

 

 

 

Eureka的使用

 

前面说过eureka是c/s模式的  server服务端就是服务注册中心,其他的都是client客户端,服务端用来管理所有服务,客户端通过注册中心,来调用具体的服务;

我们先来搭建下服务端,也就是服务注册中心;

 

新建 module   microservice-eureka-server-2001;

pom文件中加入eureka-server依赖;

yml文件中添加Eureka服务端相关信息;

在启动类中添加@EnableEurekaServer注解;

pom.xml 

<?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.hmc</groupId>
        <artifactId>springcloud</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>

 

 

 

 

 

application.yml 

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

 

 

 

MicroserviceEurekaServer2001Application.java 

package com.hmc.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);
    }

}

 

 

 

测试连接

http://localhost:2001/

搭建成功截图如下

 

 

 

 

 

 

 

Eureka中注册服务提供者

这里我们在原来的服务提供者项目 microservice-student-provider-1001  上面直接修改:

 

 

 

 

 

 

 

 

 

 

 

 

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