SpringCloud基础

SpringCloud极大的简化了分布式系统的开发，实现了微服务的快速部署和灵活应用

SpringCloud主要框架

* 服务发现--Netfix Eureka

* 服务调用--Netfix Feign

* 熔断器--Netfix Hystrix

* 服务网关--Netfix Zuul

* 分布式配置--Spring Cloud Config

* 消息总线--Spring Cloud Bus

注意SpringCloud和SpringBoot版本要一一对应，不然会报错

一。Eureka服务发现

外部的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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <packaging>pom</packaging>
    <modules>
        <module>tensquare_eureka</module>
    </modules>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
    </parent>

    <groupId>com.jinke</groupId>
    <artifactId>springboot</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.0.3.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

</project>

内部的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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot</artifactId>
        <groupId>com.jinke</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>tensquare_eureka</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
            <version>2.1.2.RELEASE</version>
        </dependency>
    </dependencies>

</project>

application.yml

server:
  port: 6868
eureka:
  client:
    register-with-eureka: false
    fetch-registery: false
    service-url:
      defaultZone: http://127.0.0.1:${server.port}/eureka/

EurekaServer.java

package com.tensquare.eureka;

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

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

直接启动看

二。Eureka服务注册

新建一个module

在pom.xml中增加

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    <version>2.1.2.RELEASE</version>
</dependency>

application.yml

server:
  port: 9004
spring:
  application:
    name: register
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:6868/eureka/
  instance:
    prefer-ip-address: true

RegisterApplication.java

package com.example.register;

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

@SpringBootApplication
@EnableEurekaClient
public class RegisterApplication {

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

}

applicaiton跑起来，看结果已经注册成功了

三。服务调用

被调register的LabelController

package com.example.register.controller;

import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/label")
@CrossOrigin
public class LabelController {

    @RequestMapping(value = "/{labelId}", method = RequestMethod.GET)
    public String findById(@PathVariable("labelId") String id) {
        System.out.println("调用成功");
        return "success";
    }

}

主调register2的ProblerController

package com.example.register2.controller;

import com.example.register2.client.BaseClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@CrossOrigin
@RequestMapping("/problem")
public class ProblemController {
    @Autowired
    private BaseClient baseClient;

    @RequestMapping(value = "/label/{labelId}", method = RequestMethod.GET)
    public String findByLabelId(@PathVariable String labelId) {
        baseClient.findById(labelId);
        return "success";
    }
}

application

package com.example.register2;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableEurekaClient
@EnableDiscoveryClient
@EnableFeignClients
public class Register2Application {

    public static void main(String[] args) {
        SpringApplication.run(Register2Application.class, args);
    }

}

BaseClient

package com.example.register2.client;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@FeignClient("register")
public interface BaseClient {

    @RequestMapping(value = "/label/{labelId}", method = RequestMethod.GET)
    public String findById(@PathVariable("labelId") String labelId);
}

eureka和register、register2服务都分别跑起来

同时可以看到register的控制台输出了“调用成功”，即代表调用其他服务成功

Spring已经实现了负载均衡，即调用服务集群时，会公平的轮流调用其中的服务

四。熔断器

熔断器可以有效避免雪崩现象

当被调服务挂掉以后，会走熔断器里面的内容

调用的服务增加实现类

package com.example.register2.client.impl;

import com.example.register2.client.BaseClient;
import org.springframework.stereotype.Component;

@Component
public class BaseClientImpl implements BaseClient {
    @Override
    public String findById(String labelId) {
        System.out.println("熔断器触发了");
        return "success";
    }
}

application.yml增加

feign:
  hystrix:
    enabled: true

五。网关

网关的作用就相当于一个中转分发站，接口

新建一个网关

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot</artifactId>
        <groupId>com.jinke</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>manager</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
            <version>2.1.2.RELEASE</version>
        </dependency>
    </dependencies>

</project>

application.yml

server:
  port: 9011
spring:
  application:
    name: manager
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:6868/eureka/
  instance:
    prefer-ip-address: true
zuul:
  routes:
    register:
      path: /register/**
      serviceId: register

application

package com.jinke.manager;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@SpringBootApplication
@EnableEurekaClient
@EnableZuulProxy
public class ManagerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ManagerApplication.class);
    }
}

然后启动服务即可

六。网关过滤

在网关模块新建一个过滤类即可

package com.jinke.manager.filter;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;

@Component
public class ManagerFilter extends ZuulFilter {
    @Override
    public String filterType() {
        //过滤器类型：之前或之后
        return "pre";
    }

    @Override
    public int filterOrder() {
        //多个过滤器的执行顺序
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        //是否开启该过滤器
        return true;
    }

    @Override
    public Object run() throws ZuulException {
        //如果设置setsendzullResponse(false)表示不再继续执行
        System.out.println("已经执行到最后了");
        return null;
    }
}

七。SpringCloudConfig配置

新建config的module

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot</artifactId>
        <groupId>com.jinke</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>config</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
            <version>2.1.3.RELEASE</version>
        </dependency>
    </dependencies>
</project>

application.xml

server:
  port: 12000
spring:
  application:
    name: config
  cloud:
    config:
      server:
        git:
          uri: https://gitee.com/king1039/springcloud-config.git
          username: xxxxxxx@qq.com
          password: xxxxxx

application

package com.jinke.config;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.config.server.EnableConfigServer;

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

服务跑起来，如果提示Authentication is required but no CredentialsProvider has been registered是因为要账号密码验证，在配置文件填上

在git上修改以后，刷新会得到新的结果

下面通过配置来调用服务

新建一个base的module

bootstrap.myl

spring:
  cloud:
    config:
      name: springcloud
      profile: config
      label: master
      uri: http://127.0.0.1:12000

git上的配置文件springcloud-config.yml

server:
  port: 9001
spring:
  application:
    name: base
eureka:
  client:
    service-url:
        defaultZone: http://127.0.0.1:6868/eureka/
  instance:
    prefer-ip-address: true

开启eureka、config、base三个服务，然后调用

流程就是先读取Git上的配置，然后拉下来，再调用服务

下面来通过bus消息开启监听

config的配置文件application.yml

server:
  port: 12000
spring:
  application:
    name: config
  cloud:
    config:
      server:
        git:
          uri: https://gitee.com/king1039/springcloud-config.git
          username: 821578297@qq.com
          password: wl802085
  rabbitmq:
    host: 172.16.10.221
management:
  endpoints:
    web:
      exposure:
        include: bus-refresh

被调的服务配置文件

server:
  port: 9001
spring:
  application:
    name: base
  rabbitmq:
    host: 172.16.10.221
eureka:
  client:
    service-url:
        defaultZone: http://127.0.0.1:6868/eureka/
  instance:
    prefer-ip-address: true

修改了被调配置文件后，使用post请求发送一次bus-refresh即可实现消息传递

如果要监听自定义的标签需要增加注解@RefreshScope

代码地址：https://github.com/king1039/SpringCloud.git

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