【Spring Cloud学习之二】服务注册和发现

时间：2024-04-24 18:06:02

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。

【Spring Cloud学习之二】服务注册和发现

二、搭建注册中心
1、新建maven工程：eureka-server

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现
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 /> <!-- lookup parent from repository -->

    </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>

        <!--eureka server -->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-eureka-server</artifactId>

        </dependency>

        <!-- spring boot test -->

        <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/

【Spring Cloud学习之二】服务注册和发现

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

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

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 /> <!-- lookup parent from repository -->

    </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/    查看服务注册情况

【Spring Cloud学习之二】服务注册和发现

http://localhost:8762/getUserList  查看服务

【Spring Cloud学习之二】服务注册和发现

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

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

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 /> <!-- lookup parent from repository -->

    </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>

        <!-- ribbon 负载均衡 -->

        <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：

【Spring Cloud学习之二】服务注册和发现

调用service-order:

【Spring Cloud学习之二】服务注册和发现

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

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

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 /> <!-- lookup parent from repository -->

    </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>

        <!-- feign客户端 -->

        <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/

【Spring Cloud学习之二】服务注册和发现

http://localhost:8765/getFeignOrderMemberAll

【Spring Cloud学习之二】服务注册和发现

【Spring Cloud学习之二】服务注册和发现

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