springcloud简介入门
文章目录
- Springcloud简介
- 入门案例
- 创建父工程microservice
- 创建通用模块microservice-common
- 创建服务提供者microservice-student-provider-1001
- 创建服务消费者microservice-student-consumer-80
- 初识eureka
- Eureka的使用
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: .html
配套参考资料:
/ springcloud项目官方主页
/ springcloud中文网 有很详细的翻译文档
/ springcloud中文论坛
Springcloud版本pom文件生成可借助网站:
/
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:microservice
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.RestTemplate,springcloud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。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.xml配置如下
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns=".0.0"xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.caoluo</groupId><artifactId>t24Springcloud</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>
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=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>microservice-common</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></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
MicroserviceCommonApplication.java
package com.caoluo.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.caoluo.microservicecommon.entity;import javax.persistence.*;
import java.io.Serializable;@Entity
@Table(name="t_springcloud_student")
public class Student implements Serializable {private static final long serialVersionUID = 1L;@Id@GeneratedValueprivate 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=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>microservice-student-provider-1001</artifactId><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>com.caoluo</groupId><artifactId>microservice-common</artifactId></dependency><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.caoluo</groupId><artifactId>microservice-common</artifactId><version>1.0-SNAPSHOT</version><scope>compile</scope></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-eureka</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: 1001context-path: /
spring:datasource:type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql://localhost:3355/t224?useUnicode=true&characterEncoding=utf8username: rootpassword: rootjpa:hibernate:ddl-auto: updateshow-sql: trueeureka: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IPclient:service-url:defaultZone: http://localhost:2001/eureka #把服务注册到eureka注册中心
info:groupId: com.javaxl.testSpringcloudartifactId: microservice-student-provider-1001version: 1.0-SNAPSHOTuserName: : 123456
MicroserviceStudentProvider1001Application.java
package com.caoluo.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.caoluo.*.*")
@EnableEurekaClient
@SpringBootApplication
public class MicroserviceStudentProvider1001Application {public static void main(String[] args) {SpringApplication.run(MicroserviceStudentProvider1001Application.class, args);}}
StudentRepository.java
package com.caoluo.microservicestudentprovider1001.repository;import com.caoluo.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.caoluo.microservicestudentprovider1001.service;import com.caoluo.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.caoluo.microservicestudentprovider1001.service.impl;import com.caoluo.microservicecommon.entity.Student;
import com.caoluo.microservicestudentprovider1001.repository.StudentRepository;
import com.caoluo.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 {@Autowiredprivate StudentRepository studentRepository;@Overridepublic void save(Student student) {studentRepository.save(student);}@Overridepublic Student findById(Integer id) {return studentRepository.findOne(id);}@Overridepublic List<Student> list() {return studentRepository.findAll();}@Overridepublic void delete(Integer id) {studentRepository.delete(id);}}
StudentProviderController.java
package com.caoluo.microservicestudentprovider1001.controller;import com.caoluo.microservicecommon.entity.Student;
import com.caoluo.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 {@Autowiredprivate 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
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>microservice-student-consumer-80</artifactId><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>com.caoluo</groupId><artifactId>microservice-common</artifactId></dependency><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.caoluo</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>
application.yml
server:port: 80context-path: /
MicroserviceStudentConsumer80Application.java
package com.caoluo.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.caoluo.microservicestudentconsumer80.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;@Configuration
public class SpringCloudConfig {@Beanpublic RestTemplate getRestTemplate(){return new RestTemplate();}
}
StudentConsumerController.java
package com.caoluo.microservicestudentconsumer80.controller;
import com.caoluo.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";@Autowiredprivate 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;}}
}
服务者访问
消费者访问
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;
在pom文件中加入eureka-server依赖;
在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=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</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: 2001context-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falseservice-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.caoluo.microserviceeurekaserver2001;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;@EnableEurekaServer
@SpringBootApplicationpublic 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
向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:
首先pom.xml修改,加上eureka客户端依赖:
pom.xml
<!--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>
然后application.yml上加上配置
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IPclient:service-url:defaultZone: http://localhost:2001/eureka #把服务注册到eureka注册中心
这里的defaultZone要和前面服务注册中心的暴露地址一致;
最后 启动类加上一个注解 @EnableEurekaClient;
package com.caoluo.microserviceeurekaserver2001;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;@EnableEurekaServer
@SpringBootApplicationpublic class MicroserviceEurekaServer2001Application {public static void main(String[] args) {SpringApplication.run(MicroserviceEurekaServer2001Application.class, args);}}
然后我们测试下,先启动服务注册中心,再启动这个服务提供者;
然后运行:http://localhost:2001/
服务提供者成功注册截图如下
点进去显示404
解决方案
解决方案如下
1、首先在服务提供者项目pom.xml里加入actuator监控依赖:
2、最后服务提供者项目application.yml加上info配置:
<!-- actuator监控引入 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
info:
groupId: com.javaxl.testSpringcloud
artifactId: microservice-student-provider-1001
version: 1.0-SNAPSHOT
userName:
phone: 123456
服务提供者pom修改
结果图如下
springcloud简介入门
文章目录
- Springcloud简介
- 入门案例
- 创建父工程microservice
- 创建通用模块microservice-common
- 创建服务提供者microservice-student-provider-1001
- 创建服务消费者microservice-student-consumer-80
- 初识eureka
- Eureka的使用
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: .html
配套参考资料:
/ springcloud项目官方主页
/ springcloud中文网 有很详细的翻译文档
/ springcloud中文论坛
Springcloud版本pom文件生成可借助网站:
/
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:microservice
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.RestTemplate,springcloud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。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.xml配置如下
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns=".0.0"xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.caoluo</groupId><artifactId>t24Springcloud</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>
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=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>microservice-common</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></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
MicroserviceCommonApplication.java
package com.caoluo.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.caoluo.microservicecommon.entity;import javax.persistence.*;
import java.io.Serializable;@Entity
@Table(name="t_springcloud_student")
public class Student implements Serializable {private static final long serialVersionUID = 1L;@Id@GeneratedValueprivate 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=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>microservice-student-provider-1001</artifactId><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>com.caoluo</groupId><artifactId>microservice-common</artifactId></dependency><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.caoluo</groupId><artifactId>microservice-common</artifactId><version>1.0-SNAPSHOT</version><scope>compile</scope></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-eureka</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: 1001context-path: /
spring:datasource:type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql://localhost:3355/t224?useUnicode=true&characterEncoding=utf8username: rootpassword: rootjpa:hibernate:ddl-auto: updateshow-sql: trueeureka: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IPclient:service-url:defaultZone: http://localhost:2001/eureka #把服务注册到eureka注册中心
info:groupId: com.javaxl.testSpringcloudartifactId: microservice-student-provider-1001version: 1.0-SNAPSHOTuserName: : 123456
MicroserviceStudentProvider1001Application.java
package com.caoluo.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.caoluo.*.*")
@EnableEurekaClient
@SpringBootApplication
public class MicroserviceStudentProvider1001Application {public static void main(String[] args) {SpringApplication.run(MicroserviceStudentProvider1001Application.class, args);}}
StudentRepository.java
package com.caoluo.microservicestudentprovider1001.repository;import com.caoluo.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.caoluo.microservicestudentprovider1001.service;import com.caoluo.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.caoluo.microservicestudentprovider1001.service.impl;import com.caoluo.microservicecommon.entity.Student;
import com.caoluo.microservicestudentprovider1001.repository.StudentRepository;
import com.caoluo.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 {@Autowiredprivate StudentRepository studentRepository;@Overridepublic void save(Student student) {studentRepository.save(student);}@Overridepublic Student findById(Integer id) {return studentRepository.findOne(id);}@Overridepublic List<Student> list() {return studentRepository.findAll();}@Overridepublic void delete(Integer id) {studentRepository.delete(id);}}
StudentProviderController.java
package com.caoluo.microservicestudentprovider1001.controller;import com.caoluo.microservicecommon.entity.Student;
import com.caoluo.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 {@Autowiredprivate 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
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>microservice-student-consumer-80</artifactId><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>com.caoluo</groupId><artifactId>microservice-common</artifactId></dependency><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.caoluo</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>
application.yml
server:port: 80context-path: /
MicroserviceStudentConsumer80Application.java
package com.caoluo.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.caoluo.microservicestudentconsumer80.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;@Configuration
public class SpringCloudConfig {@Beanpublic RestTemplate getRestTemplate(){return new RestTemplate();}
}
StudentConsumerController.java
package com.caoluo.microservicestudentconsumer80.controller;
import com.caoluo.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";@Autowiredprivate 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;}}
}
服务者访问
消费者访问
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;
在pom文件中加入eureka-server依赖;
在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=".0.0" xmlns:xsi=""xsi:schemaLocation=".0.0 .0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>com.caoluo</groupId><artifactId>t224springcloud</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: 2001context-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falseservice-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.caoluo.microserviceeurekaserver2001;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;@EnableEurekaServer
@SpringBootApplicationpublic 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
向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:
首先pom.xml修改,加上eureka客户端依赖:
pom.xml
<!--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>
然后application.yml上加上配置
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IPclient:service-url:defaultZone: http://localhost:2001/eureka #把服务注册到eureka注册中心
这里的defaultZone要和前面服务注册中心的暴露地址一致;
最后 启动类加上一个注解 @EnableEurekaClient;
package com.caoluo.microserviceeurekaserver2001;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;@EnableEurekaServer
@SpringBootApplicationpublic class MicroserviceEurekaServer2001Application {public static void main(String[] args) {SpringApplication.run(MicroserviceEurekaServer2001Application.class, args);}}
然后我们测试下,先启动服务注册中心,再启动这个服务提供者;
然后运行:http://localhost:2001/
服务提供者成功注册截图如下
点进去显示404
解决方案
解决方案如下
1、首先在服务提供者项目pom.xml里加入actuator监控依赖:
2、最后服务提供者项目application.yml加上info配置:
<!-- actuator监控引入 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
info:
groupId: com.javaxl.testSpringcloud
artifactId: microservice-student-provider-1001
version: 1.0-SNAPSHOT
userName:
phone: 123456
服务提供者pom修改
结果图如下
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