SpringCloud 服务通信方法

eureka 服务已经启动  http://localhost:8761/

注: 在启动文件加上 注解

@EnableEurekaServer 
application.yml 配置文件

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eureka:   instance:     hostname: localhost   client:     service-url:       defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ # 相互注册实现高可用     register-with-eureka: false  # true 将自己注册到eureka     fetch-registry: false   server:     enable-self-preservation: false spring:   application:     name: eureka # 服务名称,注册之后的名称 server:   port: 8761

　　

clienta 服务注册eureka

启动文件加入注解: 

@EnableEurekaClient

application.yml 配置文件 端口8000

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eureka:   client:     service-url:       defaultZone: http://localhost:8761/eureka/  #,http://localhost:8762/eureka/,http://localhost:8763/eureka/ #  instance: #    hostname: clientName spring:   application:     name: clienta

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@RestController public class TestController {     @GetMapping("/msg")     public String msg() {         return "this is clienta msg!!!";     } }

　访问  http://localhost:8000/msg     能返回结果

 

client 服务注册eureka 同clienta

在clien中调用clienta中方法

第一种方法:

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@RestController public class HelloController {         @Autowired     LoadBalancerClient loadBalancerClient;       @GetMapping("/test")     public String test() {         // 获取服务实例         ServiceInstance serviceInstance = loadBalancerClient.choose("CLIENTA");         // 根据实例获取host port         String host = serviceInstance.getHost();         int port = serviceInstance.getPort();         // 拼接url         String url = String.format("http://%s:%s%s", host, port, "/msg");         RestTemplate restTemplate = new RestTemplate();         String res = restTemplate.getForObject(url, String.class);         return res;     } }

　第二种: 配置config

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@Component public class RestTemplateConfig {       @Bean     @LoadBalanced     public RestTemplate restTemplate() {         return new RestTemplate();     } }

　　

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@RestController public class HelloController {       @Autowired     private RestTemplate restTemplate;     @GetMapping("/test")     public String test() {         String res = restTemplate.getForObject("http://CLIENTA/msg", String.class);         return res;     } }

 

　启动client 端口 8081

访问: http://localhost:8081/test

以上为基于RestTemplate 通信方式.

使用Feign通信

eureka  clienta 项目不变化
修改 client 项目:
1. 添加依赖

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<dependency>     <groupId>org.springframework.cloud</groupId>     <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency>

　2. 启动类添加注解

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1	@EnableFeignClients

　3. 创建一个接口 并增加注解

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@FeignClient(name = "CLIENTA")  // name是服务的名字 public interface ClientAClient {       @GetMapping("/msg")  // 基于路由匹配, 方法名可以不同     String msg(); }

　4. 在controller中直接使用

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@RestController public class HelloController {     @Autowired     private ClientAClient clientAClient;     @GetMapping("/test")     public String test() {         return clientAClient.msg();     } }

 

　附pom.xml文件 注意版本对应 http://spring.io/projects/spring-cloud  官网

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<?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>com.example</groupId>     <artifactId>client</artifactId>     <version>0.0.1-SNAPSHOT</version>     <packaging>war</packaging>       <name>client</name>     <description>Demo project for Spring Boot</description>     <parent>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-parent</artifactId>         <version>2.0.2.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>         <spring-cloud.version>Finchley.SR2</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-client</artifactId>         </dependency>         <dependency>             <groupId>org.springframework.cloud</groupId>             <artifactId>spring-cloud-commons</artifactId>         </dependency>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-tomcat</artifactId>             <scope>provided</scope>         </dependency>         <dependency>             <groupId>org.springframework.cloud</groupId>             <artifactId>spring-cloud-starter-openfeign</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>