十、一文搞定spring cloud重要成员-- Eureka(注册中心)

一、服务端Server搭建

依赖引入

  <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>2.2.2.RELEASE</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
     <groupId>com.kinglead</groupId>
     <artifactId>maven-spring-cloud-eureka-server</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>maven-spring-cloud-eureka-server</name>
     <description>Demo project for Spring Boot</description>
 
     <properties>
         <java.version>1.8</java.version>
         <spring-cloud.version>Hoxton.SR1</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>
             <exclusions>
                 <exclusion>
                     <groupId>org.junit.vintage</groupId>
                     <artifactId>junit-vintage-engine</artifactId>
                 </exclusion>
             </exclusions>
         </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>

添加配置

application.yml

server:
   port: 8080
 eureka:
   instance:
     hostname: localhost #标识正运行在哪台服务器上
   client:
     #register-with-eureka、fetch-registry：是否与Eureka服务进行交互，即是否集群
     register-with-eureka: false
     fetch-registry: false
     #设置与Eureka注册中心交互的地址，查询服务和注册服务用到
     service-url:
       defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ #单机
       # defaultZone: http://eureka9001.kinglead.com:9001/eureka/,http://eureka9002.kinglead.com:9002/eureka/ # 集群

修改启动类

 @SpringBootApplication
 @EnableEurekaServer //标识为Eureka服务端
 public class EurekaServerApplication {
    public static void main(String[] args) {
       SpringApplication.run(EurekaServerApplication.class, args);
    }
 
 }

访问管理页面

http://localhost:8080

二、注册服务（客户端Client搭建）

引入依赖

<?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>2.2.2.RELEASE</version>
       <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.kinglead</groupId>
    <artifactId>maven-spring-cloud-eureka-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>maven-spring-cloud-eureka-client</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
       <java.version>1.8</java.version>
       <spring-cloud.version>Hoxton.SR1</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>
          <exclusions>
             <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
             </exclusion>
          </exclusions>
       </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>

添加配置

application.yml

 spring:
   application:
     name: user-service #服务名
 server:
   port: 9200
 eureka:
   client:
     service-url:
       defaultZone: http://localhost:9000/eureka/  #Eureka服务端地址。配置多个地址，使用逗号进行分割，它将会一个一个进行尝试注册

修改启动类

@SpringBootApplication
 @EnableEurekaClient //标记为Eureka客户端
 public class EurekaClientApplication {
 
    public static void main(String[] args) {
       SpringApplication.run(EurekaClientApplication.class, args);
    }
 
 }

启动服务，看Eureka服务端是否注

三、消费服务

Spring cloud有两种服务调用方式：1、restTemplate+ribbon(cloud的负载均衡组件)；2、feign(cloud的httpclient组件,默认集成ribbo)

方式一、restTemplate+ribbon

引入依赖

<?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>2.2.2.RELEASE</version>
       <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.kinglead</groupId>
    <artifactId>maven-spring-cloud-eureka-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>maven-spring-cloud-eureka-client</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
       <java.version>1.8</java.version>
       <spring-cloud.version>Hoxton.SR1</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>
          <exclusions>
             <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
             </exclusion>
          </exclusions>
       </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>

配置文件

application.yml

 spring:
   application:
     name: service-rest #服务名
 server:
   port: 8001
 eureka:
   client:
     service-url:
       defaultZone: http://localhost:9000/eureka/  #Eureka服务端地址。配置多个地址，使用逗号进行分割，它将会一个一个进行尝试注册

修改启动类

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

创建controller

@RestController
 public class HelloController {
 
     @Resource
     HelloService helloService;
 
     @RequestMapping("/hello")
     public String hello(){
         return helloService.helloService();
     }
 
 }

创建service

@Service
 public class HelloService {
 
     @Resource
     RestTemplate restTemplate;
 
     public String helloService(){
         return restTemplate.getForObject("http://user-service/hello",String.class);
     }
 
 }

访问接口

http://localhost:8001/hello

方式二、feign

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。简而言之：Feign 采用的是基于接口的注解;Feign 整合了ribbon

引入依赖

<?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>2.2.2.RELEASE</version>
       <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.kinglead</groupId>
    <artifactId>maven-spring-cloud-eureka-comsumer-ribbo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>maven-spring-cloud-eureka-comsumer-ribbo</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
       <java.version>1.8</java.version>
       <spring-cloud.version>Hoxton.SR1</spring-cloud.version>
    </properties>
 
    <dependencies>
       <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
         </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>
          <exclusions>
             <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
             </exclusion>
          </exclusions>
       </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>

配置文件

 spring:
   application:
     name: service-feign
 server:
   port: 8001
 eureka:
   client:
     serviceUrl:
       defaultZone: http://localhost:9000/eureka/

修改启动类

 @SpringBootApplication
 @EnableEurekaClient  //标识Eureka客户端
 @EnableFeignClients  //开启feign
 public class ConsumerFeignApplication {
 
    public static void main(String[] args) {
       SpringApplication.run(ConsumerFeignApplication.class, args);
    }
 
 }

创建controller

@RestController
 public class HelloController {
 
     @Resource
     HelloAction helloAction;
 
     @RequestMapping(value = "/hello", method = RequestMethod.GET)
     public String hello(){
         return helloAction.hello();
     }
 
 }

创建接口（action）

@FeignClient(value = "user-service")
 public interface HelloAction {
 
     @RequestMapping(value = "/hello",method = RequestMethod.GET)
     String hello();
 
 }

访问

http://localhost:8001/hello

　　源码地址：https://github.com/kinglead2012/myblog

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原文地址：https://www.cnblogs.com/kinglead/p/14025199.html

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