【Spring Cloud学习之二】服务注册和发现

ゝ一世哀愁。 2021-10-29 17:08 257阅读 0赞

环境  
　　eclipse 4.7  
　　jdk 1.8  
　　Spring Boot 1.5.2  
　　Spring Cloud 1.2

一、Eureka  
Eureka是Netflix开源的一个RESTful服务，主要用于服务的注册发现。Eureka由两个组件组成：Eureka服务器和Eureka客户端。Eureka服务器用作服务注册服务器。Eureka客户端是一个java客户端，用来简化与服务器的交互、作为轮询负载均衡器，并提供服务的故障切换支持。Netflix在其生产环境中使用的是另外的客户端，它提供基于流量、资源利用率以及出错状态的加权负载均衡。  
优点：  
开源：大家可以对实现一探究竟，甚至修改源码。  
可靠：经过Netflix多年的生产环境考验，使用应该比较靠谱省心  
功能齐全：不但提供了完整的注册发现服务，还有Ribbon等可以配合使用的服务。  
基于Java：对于Java程序员来说，使用起来，心里比较有底。

![650365-20190813104525918-1580160994.jpg][]

二、搭建注册中心  
1、新建maven工程：eureka-server

![650365-20190813104240918-1129147044.jpg][]

![650365-20190813104247043-682347643.jpg][]

![650365-20190813104325882-147121623.jpg][]  
2、pom.xml

<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.wjy</groupId>
        <artifactId>eureka-server</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.2.RELEASE</version>
            <relativePath /> 
        </parent>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <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>
        </dependencies>
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Dalston.RC1</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>
        </repositories>
    
    </project>

3、application.yml

server:
      port: 8888
    eureka:
      instance:
        hostname: localhost
      client:
        #通过eureka.client.registerWithEureka：false和fetchRegistry：false来表明自己是一个eureka server.
        registerWithEureka: false
        fetchRegistry: false
        serviceUrl:
          defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

4、创建启动类

package com.wjy.app;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
    @SpringBootApplication
    @EnableEurekaServer
    public class EurekaApp {
    
        public static void main(String[] args) {
            SpringApplication.run(EurekaApp.class, args);
        }
    
    }

5、测试验证：

[http://localhost:8888/][http_localhost_8888]

![650365-20190813104448163-1127093529.jpg][]

三、服务注册-服务提供者(eureka client)  
1、新建maven工程：service-member

![650365-20190813111021384-1216683442.jpg][]

![650365-20190813111027104-336159640.jpg][]

![650365-20190813111035589-1733997429.jpg][]

2、pom.xml

<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.wjy</groupId>
        <artifactId>service-member</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.2.RELEASE</version>
            <relativePath /> 
        </parent>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</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>Dalston.RC1</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>
        </repositories>
    
    </project>

3、application.yml

eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8888/eureka/
    server:
      port: 8762
    spring:
      application:
        name: service-member

4、创建controller

package com.wjy.controller;
    
    import java.util.ArrayList;
    import java.util.List;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class MemberController {
        
        @RequestMapping("/getUserList")
        public List<String> getUserList() {
            List<String> listUser = new ArrayList<String>();
            listUser.add("zhangsan");
            listUser.add("lisi");
            listUser.add("wjy");
            return listUser;
        }
    
    }

创建启动类

package com.wjy;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    
    @SpringBootApplication
    @EnableEurekaClient
    public class MemberApp {
    
        public static void main(String[] args) {
            SpringApplication.run(MemberApp.class, args);
        }
    
    }

5、测试验证：

[http://localhost:8888/][http_localhost_8888]    查看服务注册情况

![650365-20190813111452269-794274037.jpg][]

[http://localhost:8762/getUserList][http_localhost_8762_getUserList]  查看服务

![650365-20190813111420343-1848227402.jpg][]

四、服务调用-服务消费者(eureka client)  
Spring Cloud中服务调用有两种方式：rest、feign，使用httpclient技术调用，这里案例使用rest。  
1、新建maven工程：sercice-order

![650365-20190813121936154-127348626.jpg][]

![650365-20190813121942079-1135625044.jpg][]

![650365-20190813121949015-242518640.jpg][]

2、pom.xml

<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.wjy</groupId>
        <artifactId>sercice-order</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.2.RELEASE</version>
            <relativePath /> 
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-ribbon</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>Dalston.RC1</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>
        </repositories>
    
    </project>

3、application.yml

eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8888/eureka/
    server:
      port: 8764
    spring:
      application:
        name: service-order

4、创建controller

package com.wjy.controller;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.wjy.service.OrderMemberService;
    
    @RestController
    public class OrderController {
        @Autowired
        private OrderMemberService orderMemberService;
    
        @RequestMapping("/getOrderUserAll")
        public List<String> getOrderUserAll() {
            System.out.println("订单服务开始调用会员服务");
            return orderMemberService.getOrderUserAll();
    
        }
    
    }

创建Service

package com.wjy.service;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.web.client.RestTemplate;
    
    @Service
    public class OrderMemberService {
        @Autowired
        private RestTemplate restTemplate;
    
        public List<String> getOrderUserAll() {
        return restTemplate.getForObject("http://service-member/getUserList", List.class);
        }
    
    }

创建启动类

package com.wjy;
    
    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;
    
    @EnableEurekaClient
    @SpringBootApplication
    public class OrderApp {
    
        public static void main(String[] args) {
            SpringApplication.run(OrderApp.class, args);
        }
    
        /**
         * 在工程的启动类中,通过@EnableDiscoveryClient向服务中心注册；
         * 并且向程序的ioc注入一个bean: restTemplate;
         * 并通过@LoadBalanced注解表明这个restRemplate开启负载均衡的功能。
         */
        @Bean
        @LoadBalanced
        RestTemplate restTemplate() {
            return new RestTemplate();
        }
    
    }

5、测试验证：  
先启动eureka-server，后启动service-member，最后启动sercice-order：

注册中心查看有两个服务：

![650365-20190813122139176-275926071.jpg][]

调用service-order:

![650365-20190813122148527-1705674076.jpg][]

五、Feign服务调用-服务消费者(eureka client)  
Feign是一个声明式的伪Http客户端，它使得写Http客户端变得更简单。使用Feign，只需要创建一个接口并注解。它具有可插拔的注解特性，可使用Feign注解和JAX-RS注解。Feign支持可插拔的编码器和解码器。Feign默认集成了Ribbon，并和Eureka结合，默认实现了负载均衡的效果。Feign相对rest更常用。

1、新建maven工程：service-order-feign

![650365-20190813153710588-1788270355.jpg][]

![650365-20190813153724975-1360786607.jpg][]

![650365-20190813154109040-1041075625.jpg][]

2、pom.xml

<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.wjy</groupId>
        <artifactId>service-order-feign</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.2.RELEASE</version>
            <relativePath /> 
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-ribbon</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-feign</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>Dalston.RC1</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>
        </repositories>
    
    </project>

3、application.yml

eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8888/eureka/
    server:
      port: 8765
    spring:
      application:
        name: service-order-feign

4、创建controller

package com.wjy.controller;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.wjy.service.MemberFeign;
    
    @RestController
    public class OrderFeginController {
    
        @Autowired
        private MemberFeign memberFeign; 
        
        @RequestMapping("/getFeignOrderMemberAll")
        public List<String> getToOrderMemberAll(){
            System.out.println("order fegin 工程调用member工程");
            return memberFeign.getToOrderMemberAll();
        }
    }

创建service

package com.wjy.service;
    
    import java.util.List;
    
    import org.springframework.cloud.netflix.feign.FeignClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    @FeignClient(value="service-member")
    public interface MemberFeign {
        
        @RequestMapping("/getUserList")
        public List<String> getToOrderMemberAll();
    
    }

创建启动类

package com.wjy;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.feign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableFeignClients
    public class OrderFegin {
        public static void main(String[] args) {
            SpringApplication.run(OrderFegin.class, args);
        }
    
    }

5、测试验证

[http://localhost:8888/][http_localhost_8888]

![650365-20190813154023840-1688745147.jpg][]

[http://localhost:8765/getFeignOrderMemberAll][http_localhost_8765_getFeignOrderMemberAll]

![650365-20190813154042301-1410826581.jpg][]

![650365-20190813154048037-1043240805.jpg][]

转载于:https://www.cnblogs.com/cac2020/p/11344467.html

[650365-20190813104525918-1580160994.jpg]: /images/20211029/d6bf52637d644017803cfa416e33f6a9.png
[650365-20190813104240918-1129147044.jpg]: /images/20211029/9d6f37d8bfe94710b3f5b19cd56e4462.png
[650365-20190813104247043-682347643.jpg]: /images/20211029/e0da6a10968349909710b18d7fb5160f.png
[650365-20190813104325882-147121623.jpg]: /images/20211029/9bca19bbeba24a4691d635869f554148.png
[http_localhost_8888]: http://localhost:8888/
[650365-20190813104448163-1127093529.jpg]: /images/20211029/ee3b74814d184965b9b682fdfb05b45d.png
[650365-20190813111021384-1216683442.jpg]: /images/20211029/782cd2d91df24991abc8d8cf59ae8a81.png
[650365-20190813111027104-336159640.jpg]: /images/20211029/2497438016ef41bfa39299253c5201b6.png
[650365-20190813111035589-1733997429.jpg]: /images/20211029/29c7d868b2f742688904b512d0a10384.png
[650365-20190813111452269-794274037.jpg]: /images/20211029/d0cd36b47b2e4f93a9ce6c2f920a040f.png
[http_localhost_8762_getUserList]: http://localhost:8762/getUserList
[650365-20190813111420343-1848227402.jpg]: /images/20211029/817cdcd94dbe42e9877a6cd672981ee5.png
[650365-20190813121936154-127348626.jpg]: /images/20211029/37ea4b689abf448986203f3de873a694.png
[650365-20190813121942079-1135625044.jpg]: /images/20211029/eab09a14e4884a2fa69bd7db976f6595.png
[650365-20190813121949015-242518640.jpg]: /images/20211029/afd43cfd94884fa9a684b931d78e1fac.png
[650365-20190813122139176-275926071.jpg]: /images/20211029/97e6f42988ee467caef1c62a72539211.png
[650365-20190813122148527-1705674076.jpg]: /images/20211029/b20cdb5d0d6a4d6a8236d4469ef4bac5.png
[650365-20190813153710588-1788270355.jpg]: /images/20211029/50cccd539c664e90b1fe691969f3cb1b.png
[650365-20190813153724975-1360786607.jpg]: /images/20211029/e90b36e2e0c04afea2916606d7f2eb11.png
[650365-20190813154109040-1041075625.jpg]: /images/20211029/436a5631f2f647c4b50c167f6e1e539d.png
[650365-20190813154023840-1688745147.jpg]: /images/20211029/50c14aed66194da79455e4b86ba22a91.png
[http_localhost_8765_getFeignOrderMemberAll]: http://localhost:8765/getFeignOrderMemberAll
[650365-20190813154042301-1410826581.jpg]: /images/20211029/c86c52fc1b794a269ab29c6b5994c0a2.png
[650365-20190813154048037-1043240805.jpg]: /images/20211029/49b4823ee9a541d1b8cbe14c57baf678.png