spring cloud实例Dome详细搭建（一）

ideal创建Springcloud实例

准备工作：

1.首先创建一个父项目，一个普通的java项目，直接next

 

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>

    <groupId>org.example</groupId>
    <artifactId>springcloudParent</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

</project>

开始创建spring cloud的注册中心（eureka server）

 

 

 

 

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>eurekaserver</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eurekaserver</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>3.1.0</version>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

配置一下maven，clean install下

 

 配置一下application.yml

server:  # 服务端口
  port: 7001
spring:
  application:  # 应用名字，eureka 会根据它作为服务id
    name: 127.0.0.1
eureka:
  instance:
    hostname: localhost
  client:
    register-with-eureka: false  # 不向eureka server 注册自己
    fetch-registry: false  # 不向eureka server 获取服务列表

 配置一下EurekaserverApplication.java

package com.example.eurekaserver;

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

@SpringBootApplication
@EnableEurekaServer
public class EurekaserverApplication {

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

}

启动下，访问下localhost:7001

创建一个服务提供者

1.创建项目方式和eureka一致，在父项目下创建子项目，直接配置pom.xml

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>eurekaprovider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eurekaprovider</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</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-web</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.1</version>
                <configuration>
                    <skipTests>true</skipTests>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

 EurekaproviderApplication.java

package com.example.eurekaprovider;

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

@SpringBootApplication
@EnableEurekaClient
public class EurekaproviderApplication {

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

}

新建一个ProviderController.java的类

package com.example.eurekaprovider;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("provider")
public class ProviderController {

    @RequestMapping("get")
    public String getData(){
        return "提供了数据";
    }
}

application.yml

server:
  port: 8001
spring:
  application:
    name: spring-cloud-order-service-provider
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka
ribbon:
  eureka:
    enabled: true

　启动EurekaproviderApplication类

 

访问localhost:7001

 可以看到8001服务提供者已经注册上去了

访问http://localhost:8001/provider/get，可以看到如下页面

创建一个服务消费者

同样的方法创建model eurekaconsumer，创建服务消费者

 EurekaconsumerApplication.java

package com.example.eurekaconsumer;

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

@SpringBootApplication
public class EurekaconsumerApplication {

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

}

 ConsumerController.java

package com.example.eurekaconsumer;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
@RequestMapping("consumer")
public class ConsumerController {
    //资源路径
    private final String url = "http://127.0.0.1:8001/provider/get";

    @RequestMapping("get")
    public String get(){
        RestTemplate template = new RestTemplate();
        String data = template.getForObject(url, String.class);
        return data;
    }
}

application.yml

server:
  port: 9001

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>eurekaconsumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eurekaconsumer</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</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>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

</project>

启动项目后，访问 http://localhost:9001/consumer/get

创建一个Zuul网关

Zuul的主要功能是路由转发和过滤器。路由功能是微服务的一部分，比如/api/user转发到到user服务，/api/shop转发到到shop服务。zuul默认和Ribbon结合实现了负载均衡的功能。

类似创建consumer和provider创建一个Zuul

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>zuul</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>zuul</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
            <version>2.0.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.1</version>
                <configuration>
                    <skipTests>true</skipTests>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>3.1.0</version>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>repository.springframework.maven.release</id>
            <name>Spring Framework Maven Release Repository</name>
            <url>http://maven.springframework.org/milestone/</url>
        </repository>
        <repository>
            <id>org.springframework</id>
            <url> http://maven.springframework.org/snapshot</url>
        </repository>
        <repository>
            <id>spring-milestone</id>
            <name>Spring Maven MILESTONE Repository</name>
            <url>http://repo.spring.io/libs-milestone</url>
        </repository>
        <repository>
            <id>spring-release</id>
            <name>Spring Maven RELEASE Repository</name>
            <url>http://repo.spring.io/libs-release</url>
        </repository>
    </repositories>

</project>

这里需要更新之前全部项目的springcloud和springboot版本

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
</properties>

ZuulDemo.java

package com.example.zuul;

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;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;


@SpringBootApplication(exclude={DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})
@EnableEurekaClient
@EnableZuulProxy
public class ZuulDemo{
    public static void main(String[] args){
        SpringApplication.run(ZuulDemo.class);
    }
}

application.yml

server:
  port: 9527
spring:
  application:
    name: ZUUL-SERVER		#Zuul网关在Eureka的服务名称，随便取
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka	 #Eureka的注册地址
zuul:
  routes:
    provider.serviceId: TEST-PROVIDER	#没有提示，自己取名称，值为服务的名称

启动后如下：

启动网关，通过网关访问服务提供
规则：localhost名:9527/网关服务名称(小写)/服务提供者名称(小写)/服务路径
例：http://127.0.0.1:9527/zuul-server/spring-cloud-order-service-provider/provider/get

可以在application.yml配置访问路径

server:
  port: 9527
spring:
  application:
    name: ZUUL-SERVER
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka
zuul:
  routes:
    traditional-url:
      path: /test/**
      url: http://localhost:8001/f

访问地址如下：http://desktop-f8m87f4.china.huawei.com:9527/test/provider/get

　

Fegin的内部调用

Feign是一个声明式的web service客户端，他让微服务之间的调用变得更简单，类似Controller调用Service，可在服务之间进行调用，简化调用流程。

我们要在一个服务提供者中使用另一个服务提供者的服务，需要使用fegin进行内部服务的调用

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>feign</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>feign</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</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.cloud</groupId>
            <artifactId>spring-cloud-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>repository.springframework.maven.release</id>
            <name>Spring Framework Maven Release Repository</name>
            <url>http://maven.springframework.org/milestone/</url>
        </repository>
        <repository>
            <id>org.springframework</id>
            <url> http://maven.springframework.org/snapshot</url>
        </repository>
        <repository>
            <id>spring-milestone</id>
            <name>Spring Maven MILESTONE Repository</name>
            <url>http://repo.spring.io/libs-milestone</url>
        </repository>
        <repository>
            <id>spring-release</id>
            <name>Spring Maven RELEASE Repository</name>
            <url>http://repo.spring.io/libs-release</url>
        </repository>
    </repositories>

</project>

接口DataClient.java

package com.example.feign;

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

@FeignClient(value = "spring-cloud-order-service-provider")
@RequestMapping("provider")
public interface DataClient {
    //和调用服务controller的一致
    @RequestMapping("get")
    public String getData();
}

DataFeignController.java

package com.example.feign;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("consumer")
public class DataFeignController {

    @Autowired
    private DataClient dataClient;

    @RequestMapping("feignGet")
    public String get(){
        return dataClient.getData();
    }
}

FeignApplication.java

package com.example.feign;

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

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class FeignApplication {

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

}

application.yml

server:
  port: 9002
spring:
  application:
    name: FEIDEMO
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka

访问http://localhost:7001/

访问http://desktop-f8m87f4.china.huawei.com:9002/consumer/feignGet

负载均衡ribbon

ribbon主要是做负载均衡，要做负载均衡就要有多个服务提供者，在消费者调用时进行负载均衡。

创建第二个服务提供者

复制第一个eurekaprovider

配置依赖和原来提供者一致（拷贝server-provider依赖，controller，配置文件）
唯一修改（配置文件application.yml中的端口更改，其他不要改）

application.yml

server:
  port: 8002
spring:
  application:
    name: spring-cloud-order-service-provider
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka
ribbon:
  eureka:
    enabled: true

区分一下ProviderController.java

ProviderController.java

package com.example.eurekaclient;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("provider")
public class ProviderController {

    @RequestMapping("get")
    public String getData(){
        return "提供了数据2222";
    }
}

然后创建一个消费者进行负载均衡调用

 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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>ribbon</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ribbon</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.3.RELEASE</version>
        </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>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>3.1.0</version>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

启动类RibbonApplication.java

package com.example.ribbon;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableEurekaClient
public class RibbonApplication {

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

    @Bean
    @LoadBalanced //开启负载均衡的功能
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }
}

ConsumerRibbonController.java

package com.example.ribbon;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
@RequestMapping("consumer")
public class ConsumerRibbonController {

    @Autowired
    private RestTemplate restTemplate;

    private final String URL = "http://spring-cloud-order-service-provider/provider/get";

    @GetMapping("get")
    public String get() {
        String data = restTemplate.getForObject(URL, String.class);
        return data;
    }
}

配置文件application.yml

server:
  port: 9003
eureka:
  client:
    registerWithEureka: false #不注册到Eureka,不在注册中心显示
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka

测试(轮询策略)：

熔断器（hystrix）

在微服务架构中，微服务之间通过网络进行通信，存在相互依赖，当其中一个服务不可用时，有可能会造成雪崩效应。要防止这样的情况，必须要有容错机制来保护服务。
Hystrix是Netflix开源的一个延迟和容错库，它主要实现了以下几点：

  • 包裹请求

　　　　使用HystrixCommand（或HystrixObservableCommand）包裹对依赖的调用逻辑，每个命令在独立线程中执行。

  • 跳闸机制

　　　　当某服务的错误率超过一定阈值时，Hystrix可以自动或手动跳闸，停止请求该服务一段时间。

  • 资源隔离

　　　　Hystrix为每个依赖都维护了一个小型的线程池（或信号量），如果该线程池已满，发往该依赖的请求就被立即拒绝。

  • 监控

　　　　Hystrix可以近乎实时地监控运行指标和配置的变化。

  • 回退机制

　　　　当请求失败、超时、被拒绝，或者当断路器打开时，执行回退逻辑。

  • 自我修复

　　　　当断路器打开一段时间后，会自动进入“半打开”状态，允许一个请求访问依赖的服务，如果该请求成功，则关闭断路器，否则继续保持打开状态。

创建一个服务器提供者（hystrix），模拟业务服务

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>hystrix</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>hystrix</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.3.RELEASE</version>
        </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.cloud</groupId>
            <artifactId>spring-cloud-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.yml

server:
  port: 8004
spring:
  application:
    name: TEST-HYSTRIX-PROVIDER   #服务名称
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka #注册到Eureka的地址

HystrixApplication.java

package com.example.hystrix;

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

@SpringBootApplication
@EnableEurekaClient
public class HystrixApplication {

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

HystrixProviderController.java

package com.example.hystrix;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("provider")
public class HystrixProviderController {
    @GetMapping("get/{num}")
    public String get(@PathVariable("num") Integer num) {
        if (num == 123) {
            throw new RuntimeException("FAILED");
        }
        return num + "==SUCCEED";
    }
}

启动项目后访问http://localhost:8004/provider/get/111

访问http://localhost:8004/provider/get/123

创建一个基于fegin的消费者

 

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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>hystrix-feign</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>hystrix-feign</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR4</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</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.cloud</groupId>
            <artifactId>spring-cloud-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>repository.springframework.maven.release</id>
            <name>Spring Framework Maven Release Repository</name>
            <url>http://maven.springframework.org/milestone/</url>
        </repository>
        <repository>
            <id>org.springframework</id>
            <url> http://maven.springframework.org/snapshot</url>
        </repository>
        <repository>
            <id>spring-milestone</id>
            <name>Spring Maven MILESTONE Repository</name>
            <url>http://repo.spring.io/libs-milestone</url>
        </repository>
        <repository>
            <id>spring-release</id>
            <name>Spring Maven RELEASE Repository</name>
            <url>http://repo.spring.io/libs-release</url>
        </repository>
    </repositories>

</project>

application.xml

server:
  port: 9004
eureka:
  client:
    registerWithEureka: false #不注册到Eureka,不在注册中心显示
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka
feign:
  hystrix:
    enabled: true #开启熔断支持

HystrixConsumerController.java

package com.example.hystrixfeign;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("consumer")
public class HystrixConsumerController {
    @Autowired
    private ProviderClient providerClient;

    @GetMapping("get/{num}")
    public String get(@PathVariable("num") String num) {
        String data = providerClient.get(num);
        return data;
    }
}

HystrixFeignApplication.java

package com.example.hystrixfeign;

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

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class HystrixFeignApplication {

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

}

接口ProviderClient.java

package com.example.hystrixfeign;

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

@FeignClient(value = "TEST-HYSTRIX-PROVIDER", fallbackFactory = ProviderClientFactory.class)
@RequestMapping("provider")
public interface ProviderClient {

    @GetMapping("get/{num}")
    public String get(@PathVariable("num") String num);
}

ProviderClientFactory.java

package com.example.hystrixfeign;

import feign.hystrix.FallbackFactory;
import org.springframework.stereotype.Component;

@Component
public class ProviderClientFactory implements FallbackFactory<ProviderClient> {
    @Override
    public ProviderClient create(Throwable throwable) {
        return new ProviderClient() {
            @Override
            public String get(String num) {
                return "Feign调用失败";
            }
        };
    }
}

访问http://localhost:9004/consumer/get/123

访问http://localhost:9004/consumer/get/111

　

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原文地址：https://www.cnblogs.com/longlyseul/p/14972880.html