spring cloud服务提供与调用示例

本文创建方式采用intellij IDEA 创建项目

1.创建基于Eureka的注册中心。

在打开项目中右键，选择new 选择moudle

然后下一步

输入要创建的项目的信息

选择web下面的web，选择cloud discovery下面的 Eureka server 下一步，创建项目

然后同步pom.xml文件内容、

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>server</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</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>

        <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>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

</project>

在启动文件中选择

@SpringBootApplication
@EnableEurekaServer
public class ServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(ServerApplication.class, args);
    }

}

配置文件

server:
  port: 8000
eureka:
  instance:
    hostname: localhost
  client:
    fetch-registry: false
    register-with-eureka: false
    serviceUrl:
      defaultZone: http://localhost:8000/eureka/
spring:
  application:
    name: spring-cloud-eureka

　　创建完，我们去运行下，运行正常后，我们去访问localhost:8000, 到下面的界面，这样我们Eureka 注册中心就创建成功，

下面我们去创建server端，和client；

server端呢创建中与Eureka选择不同的在于cloud discovery中，这里需要选择cloud Discovery

然后创建完，去同步对应的pom.xml文件

在启动类编写如下

@SpringBootApplication
@EnableDiscoveryClient
public class ServeroneApplication {

    public static void main(String[] args) {
        SpringApplication.run(ServeroneApplication.class, args);
    }

}

配置文件
server:
  port: 8001
eureka:
  instance:
    hostname: localhost
  client:
    serviceUrl:
      defaultZone: http://localhost:8000/eureka/
spring:
  application:
    name: spring-serverserver

我们需要编写一个提供服务的接口

@RestController
public class HelloController {

    @RequestMapping("/hello")
    public String indesx(@RequestParam String name) {
        return "hello "+name+"，this is first messge";
    }
}

这样我们就可以实现我们的server端

然后我们去创建client端

client端多需要在server上创建多一个Feign

那么我们在启动类，如下

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

配置文件

server:
  port: 8002
eureka:
  instance:
    hostname: localhost
  client:
    serviceUrl:
      defaultZone: http://localhost:8000/eureka/
spring:
  application:
    name: spring-client

那么我们去写调用server的服务

@FeignClient(name= "spring-serverserver")
public interface HelloRemote {
    @RequestMapping(value = "/hello")
    public String hello(@RequestParam(value = "name") String name);
}

实现接口

@RestController
public class ConsumerController {

    @Autowired
    HelloRemote lloRemote;

    @RequestMapping("/hello/{name}")
    public String index(@PathVariable("name") String name) {
        return lloRemote.hello(name);
    }
}

这样我们就实现了服务的注册与调用。

那么我们去启动服务进行测试，服务注册成功，我们去启动服务调用端