SpringCloud——Eureka_spring-cloud feignclients并发调用eureka服务+jsonmappinge

Eureka client启动后会以默认30秒的周期想Eureka server发送心跳；而Eureka Server默认在3个周期内也就是90秒没有收到client的心跳，就会把该client从注册中心移除。

快速搭建一个注册中心（Eureka服务端）：

1.创建SpringBoot项目，引入Eureka-server和springCloud依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
<properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.M3</spring-cloud.version>
    </properties>
 <dependencies>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</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>

2.在启动类上添加@EnableEurekaServer注解

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

3.application.yml配置文件

server:
  port: 8761
eureka:
  client:
    fetch-registry: false
    register-with-eureka: false
    service-url:
        defaultZone: http://127.0.0.1:8761/eureka

以上搭建了服务端，启动就可以了，下面创建客户端

同样，新建boot项目

1，引入客户端依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.0.RELEASE</version>
        <relativePath/> 
    </parent>
   
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.M3</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>
 
    </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>

2，在启动类上添加@EnableEurekaClient 或者@EnableDiscoveryClient注解，区别是后者是SpringClou的，不仅可以用于Eureka还可以是服务作为客户端注册到其他的注册中心中

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

3，配置文件

server：
    port：8070
eureka:
    client:
        service-url:
            defaultZone: http://127.0.0.1:8761/eureka/

以上创建了一个eureka客户端，启动上面的服务端，再启动客户端，就可以成功的注册到服务端