springcloud-Netflix创建服务消费者

springcloud-Netflix创建服务消费者
- Ribbon
  - 创建服务消费者-Ribbon方式
  - ribbon的架构
- Feign

在微服务架构中，业务都会被拆分成一个独立的服务，服务与服务的通讯是基于 http restful 的。Spring cloud 有两种服务调用方式，两种都是http方式的不是rpc方式

一种是 ribbon + restTemplate

另一种是 feign。首先讲解下基于 ribbon + rest

Ribbon

创建服务消费者-Ribbon方式

Ribbon 是一个负载均衡客户端，可以很好的控制 http 和 tcp 的一些行为。

创建方式也是，在总工程下面创建maven工程包，导入pom.xml，application.yml，Application入口类；以及编写自己的业务逻辑

1.创建一个 hello-spring-cloud-web-admin-ribbon 服务消费者项目

POM.XML，导入springboot和Ribbon的依赖

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <parent>

        <groupId>com.outlook.liufei32</groupId>

        <artifactId>hello-spring-cloud-dependencies</artifactId>

        <version>1.0.0-SNAPSHOT</version>

        <relativePath>../hello-spring-cloud-dependencies/pom.xml</relativePath>

    </parent>

    <artifactId>hello-spring-cloud-web-admin-ribbon</artifactId>

    <packaging>jar</packaging>

    <name>hello-spring-cloud-web-admin-ribbon</name>

    <url>https://github.com/Swagger-Ranger</url>

    <inceptionYear>2018-Now</inceptionYear>

    <dependencies>

        <!-- Spring Boot Begin -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-tomcat</artifactId>

        </dependency>

        <!--web需要thymeleaf模板引擎-->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-thymeleaf</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-actuator</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

        <!-- Spring Boot End -->

        <!-- Spring Cloud Begin -->

        <dependency>

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

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

        </dependency>

        <!--ribbon的插件-->

        <dependency>

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

            <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>

        </dependency>

        <!-- Spring Cloud End -->

        <!-- 解决 thymeleaf 模板引擎一定要执行严格的 html5 格式校验问题 -->

        <dependency>

            <groupId>net.sourceforge.nekohtml</groupId>

            <artifactId>nekohtml</artifactId>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

                <configuration>

                    <mainClass>com.outlook.liufei32.hello.spring.cloud.web.admin.ribbon.WebAdminRibbonApplication</mainClass>

                </configuration>

            </plugin>

        </plugins>

    </build>

</project>

完善结构目录，并将服务注册到服务中心

在启动类上加入@EnableDiscoveryClient 注解注册到服务中心

package com.outlook.liufei32.hello.spring.cloud.web.admin.ribbon;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication

@EnableDiscoveryClient    //发现服务注解，注解是不分顺序的

public class WebAdminRibbonApplication {

    public static void main( String[] args ) {

        SpringApplication.run(WebAdminRibbonApplication.class, args);

    }

}

配置application.yml

spring:

  application:

    name: hello-spring-cloud-web-admin-ribbon

  thymeleaf:

    cache: false

    mode: LEGACYHTML5

    encoding: UTF-8

    servlet:

      content-type: text/html

server:

  port: 8764

eureka:

  client:

    serviceUrl:

      defaultZone: http://localhost:8761/eureka/

配置Configuration，注入RestTemplate 的 Bean，并通过 @LoadBalanced 注解表明开启负载均衡功能

package com.outlook.liufei32.hello.spring.cloud.web.admin.ribbon.config;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.web.client.RestTemplate;

@Configuration

public class RestTemplateConfiguration {

    @Bean//生成配置一个Bean

    @LoadBalanced//访问负载均衡器，自动去寻找服务提供者

    public RestTemplate restTemplate() {

        return new RestTemplate();

    }

}

创建service，来测试请求restTemplate负载均衡

package com.outlook.liufei32.hello.spring.cloud.web.admin.ribbon.service;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import org.springframework.web.client.RestTemplate;

@Service

public class AdminService {

    @Autowired

    private RestTemplate restTemplate;//因为我在config里配置了restTemplate Bean所以能自动注入

    /**

     * url:就是http://+服务名，即在你要调用的service微服务里applicat.yml中配置的服务名，restTemplate会自动去寻找可用的服务

     * @param message

     * @return

     */

    public String sayHi( String message ) {

        return restTemplate.getForObject("http://hello-spring-cloud-service-admin/hi?message=" + message, String.class);

    }

}

创建controller来解释web访问然后去访问service

package com.outlook.liufei32.hello.spring.cloud.web.admin.ribbon.controller;

import com.outlook.liufei32.hello.spring.cloud.web.admin.ribbon.service.AdminService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class AdminController {

    @Autowired

    private AdminService adminService;

    @RequestMapping(value = "hi",method = RequestMethod.GET)

    public String sayHi( @RequestParam String message ) {

        return adminService.sayHi(message);

    }

}

ribbon的架构

Feign

创建包和基本项目结构

在总的包下新建

spring-cloud-web-admin-feign工程，导入pom.xml

<?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>com.outlook.liufei32</groupId>

        <artifactId>spring-cloud-dependencies</artifactId>

        <version>1.0.0-SNAPSHOT</version>

        <relativePath>../spring-cloud-dependencies/pom.xml</relativePath>

    </parent>

    <artifactId>spring-cloud-web-admin-feign</artifactId>

    <packaging>jar</packaging>

    <name>spring-cloud-web-admin-feign</name>

    <url></url>

    <inceptionYear>2019-Now</inceptionYear>

    <dependencies>

        <!-- Spring Boot Begin -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-tomcat</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-thymeleaf</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-actuator</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

        <!-- Spring Boot End -->

        <!-- Spring Cloud Begin -->

        <dependency>

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

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

        </dependency>

        <dependency>

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

            <artifactId>spring-cloud-starter-openfeign</artifactId>

        </dependency>

        <!-- Spring Cloud End -->

        <!-- 解决 thymeleaf 模板引擎一定要执行严格的 html5 格式校验问题 -->

        <dependency>

            <groupId>net.sourceforge.nekohtml</groupId>

            <artifactId>nekohtml</artifactId>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

                <configuration>

                    <mainClass>com.outlook.liufei32.spring.cloud.web.admin.feign.WebAdminFeignApplication</mainClass>

                </configuration>

            </plugin>

        </plugins>

    </build>

</project>

其中feign的依赖就是:

<dependency>

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

    <artifactId>spring-cloud-starter-openfeign</artifactId>

</dependency>

创建启动类

package com.outlook.liufe32.spring.cloud.web.admin.feign;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication

@EnableDiscoveryClient//发现服务

@EnableFeignClients//Feign

public class WebAdminFeignApplication {

    public static void main( String[] args ) {

        SpringApplication.run(WebAdminFeignApplication.class, args);

    }

}

配置yml

spring:

  application:

    name: spring-cloud-web-admin-feign

  thymeleaf:

    cache: false

    mode: LEGACYHTML5

    encoding: UTF-8

    servlet:

      content-type: text/html

server:

  port: 8765

eureka:

  client:

    serviceUrl:

      defaultZone: http://localhost:8761/eureka/

创建Feign访问服务的接口和访问controller

这一步是不同于ribbon的地方，feign其实也集成了ribbon

package com.outlook.liufe32.spring.cloud.web.admin.feign.service;

import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(value = "spring-cloud-service-admin")//这里就是访问的服务名，在服务提供者的yml里或者去eureka里找服务名

public interface AdminService {

//这里的写法就类似controller但不是方法而是接口

    @RequestMapping(value = "hi", method = RequestMethod.GET)

    public String sayHi( @RequestParam(value = "message") String message );

}

创建controller

package com.outlook.liufe32.spring.cloud.web.admin.feign.controller;

import com.outlook.liufe32.spring.cloud.web.admin.feign.service.AdminService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class WebAdminController {

    @Autowired

    private AdminService adminService;

    @RequestMapping(value = "hi", method = RequestMethod.GET)

    public String sayHi(@RequestParam(value = "message") String message) {

        return adminService.sayHi(message);

    }

}

测试访问

http://localhost:8765/hi?message=HelloFeign

访问feign的fontroller，就可以看到feign去调用了不同的服务提供者端口，即不同的服务者实例

Hi，your message is :"HelloFeign" i am from port：8762

Hi，your message is :"HelloFeign" i am from port：8763

本博客为Swagger-Ranger的笔记分享，文章会持续更新

文中源码地址： https://github.com/Swagger-Ranger

欢迎交流指正，如有侵权请联系作者确认删除： liufei32@outlook.com