第三章：简单springcloud微服务项目，Fegin和ribbon微服务通信方式

本章注意讲解spring cloud微服务两种通信方式，本章节依赖于第一、第二章节。

讲解开始前的准备如下：

    一、先新建一个Maven Project模块项目，项目名称为module-oauth-server，参考第一章节步骤创建。

    二、右键module-oauth-server，在该项目下创建一个Maven Module项目，项目名称为module-oauth-api。

    三、再创建一个Maven Module项目，项目名称为module-oauth-resources，在pom文件依赖api项目。

项目结构图如下：

1）module-oauth-server项目pom.xml配置如下：

<?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.maven.xm</groupId>
  <artifactId>module-oauth-server</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>
  
  <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.2.RELEASE</version>
  </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.dependencies.version>Camden.SR7</spring.cloud.dependencies.version>
      <io.springfox>2.7.0</io.springfox>
  </properties>
  
  <dependencyManagement>
       <dependencies>
           <dependency>
               <groupId>org.springframework.cloud</groupId>
               <artifactId>spring-cloud-dependencies</artifactId>
               <version>${spring.cloud.dependencies.version}</version>
               <type>pom</type>
               <scope>import</scope>
           </dependency>
		
       </dependencies>
   </dependencyManagement>
   
   <build>
   		<plugins>
	        <plugin>
	            <groupId>org.apache.maven.plugins</groupId>
	            <artifactId>maven-surefire-plugin</artifactId>
	            <configuration>
	            	<source>${java.version}</source>
                  	<target>${java.version}</target>
                  	<encoding>UTF-8</encoding>
                  	<skipTests>true</skipTests>
	            </configuration>
	        </plugin>
	    </plugins>
	</build>
	
	<repositories>
	    <repository>
	      	<id>central</id>
	      	<name>Central Repository</name>
	      	<url>https://repo.maven.apache.org/maven2</url>
	      	<layout>default</layout>
	      	<snapshots>
	        	<enabled>false</enabled>
	      	</snapshots>
	    </repository>
	 </repositories>
	 
	<modules>
		<module>module-oauth-api</module>
		<module>module-oauth-resources</module>
	</modules>
</project>

2）module-oauth-resources项目pom.xml配置如下：

<?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.maven.xm</groupId>
    <artifactId>module-oauth-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <artifactId>module-oauth-resources</artifactId>
  <packaging>jar</packaging>
  
  <dependencies>
  	  <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-eureka</artifactId>
      </dependency>
      
      <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-feign</artifactId>
      </dependency>
      
      <dependency>
			<groupId>io.springfox</groupId>
			<artifactId>springfox-swagger2</artifactId>
			<version>${io.springfox}</version>
		</dependency>
		<dependency>
		    <groupId>io.springfox</groupId>
		    <artifactId>springfox-swagger-ui</artifactId>
		    <version>${io.springfox}</version>
		</dependency>
		
		<!-- 引用api项目 -->
		<dependency>
		    <groupId>com.maven.xm</groupId>
		    <artifactId>module-oauth-api</artifactId>
		    <version>0.0.1-SNAPSHOT</version>
		</dependency>
		
  </dependencies>
</project>

3）module-oauth-resources项目src/main/resources下新创建一个application.properties文件，内容如下：

server.port = 8763
spring.application.name = module-oauth-server
eureka.client.serviceUrl.defaultZone = http://localhost:8761/eureka/

4）module-oauth-resources项目src/main/java下

     com.maven.xm.oauth.OAuthApplication内容：

package com.maven.xm.oauth;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients("com.maven.xm")
public class OAuthApplication {
	
	private static final Logger LOGGER = LoggerFactory.getLogger(OAuthApplication.class);

	public static void main(String[] args) {
		SpringApplication.run(OAuthApplication.class);
		LOGGER.info("********************OAuth Server Started********************");
	}

}

    com.maven.xm.oauth.Swagger2内容：

package com.maven.xm.oauth;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

/**
 * swagger2
 * 地址: http://localhost:8763/swagger-ui.html
 * @author ouyangjun
 *
 */
@Configuration
@EnableSwagger2
@ComponentScan("com.maven.xm")
public class Swagger2 {
	
	@Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.app.maven.oauth.controller"))
                .paths(PathSelectors.any())
                .build();
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("Spring Boot中使用Swagger2构建RESTful APIs")
                .description("更多Spring Boot相关文章请关注：http://blog.didispace.com/")
                .termsOfServiceUrl("http://blog.didispace.com/")
                .version("1.0")
                .build();
    }
    
}

    com.maven.xm.oauth.controller.DemoController内容：

package com.maven.xm.oauth.controller;

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

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;

@Api(tags = "module-oauth模块,用户Demo Controller")
@RestController
@RequestMapping(value = "/demo")
public class DemoController {
	
	@ApiOperation(value="module模块,Test方法", notes="Test")
	@RequestMapping(value = "/hello", method = RequestMethod.GET)
	public String hello(){
		return "Hello Demo ouyangjun!";
	}
	
}

5）module-oauth-api项目pom.xml配置如下：

<?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.maven.xm</groupId>
    <artifactId>module-oauth-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <artifactId>module-oauth-api</artifactId>
  <packaging>jar</packaging>
  
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  
  <dependencies>
      <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-feign</artifactId>
      </dependency>
      
  </dependencies>
  
</project>

6）module-oauth-api项目com.maven.xm.oauth.api.IDemoApi内容如下：

package com.maven.xm.oauth.api;

import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
 * @FeignClient中value的名称要跟module-oauth-resources项目中application.properties文件的name保持一致
 * @author Administrator
 *
 */
@FeignClient(
		value = "module-oauth-server"
		)
public interface IDemoApi {
	
	@RequestMapping(value = "/demo/hello", method = RequestMethod.GET)
	public String hello();
	
}

7）到这一步已经可以先单独运行进行访问了，先启动EurekaServerApplication，再启动OAuthApplication

     启动成功之后，再浏览器地址栏中输入(该方式还不算微服务之间通信)：http://localhost:8763/demo/hello

现在开始增加Fegin和ribbon通信代码：

一）在xm-web-controller项目pom.xml文件中增加如下配置：

<!-- fegin通信jar -->
		<dependency>
          	<groupId>org.springframework.cloud</groupId>
          	<artifactId>spring-cloud-starter-feign</artifactId>
      	</dependency>
      
      	<!-- ribbon通信jar -->
      	<dependency>
          	<groupId>org.springframework.cloud</groupId>
          	<artifactId>spring-cloud-starter-ribbon</artifactId>
      	</dependency>
	
		<!-- 引用其它微服务模块暴露出来的接口，不引用具体实现类 -->
		<dependency>
		    <groupId>com.maven.xm</groupId>
		    <artifactId>module-oauth-api</artifactId>
		    <version>0.0.1-SNAPSHOT</version>
		</dependency>

二）在xm-web-controller项目下WebApplication.java中新增代码：

package com.maven.xm.web;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

/**
 * @EnableDiscoveryClient基于spring-cloud-commons, @EnableEurekaClient基于spring-cloud-netflix。
         就是如果选用的注册中心是eureka，那么就推荐@EnableEurekaClient，如果是其他的注册中心，那么推荐使用@EnableDiscoveryClient。
   @EnableEurekaClient源码上有@EnableDiscoveryClient注解，可以说基本就是EnableEurekaClient有@EnableDiscoveryClient的功能
 * 
 * @author ouyangjun
 * 
 */
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients("com.maven.xm")
public class WebApplication {

	private static final Logger LOGGER = LoggerFactory.getLogger(WebApplication.class);
	
	public static void main(String[] args) {
		SpringApplication.run(WebApplication.class);
		LOGGER.info("********************Web Server Started********************");
	}
	
	/**
	 * 新增ribbon通信工具类
	 * @return
	 */
	@Bean
        @LoadBalanced
        RestTemplate restTemplate() {
            return new RestTemplate();
        }
	
}

三）整改一下xm-web-controller项目中DemoController.java，代码如下：

package com.maven.xm.web.controller;

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.RestController;

import com.maven.xm.web.service.DemoService;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;

/**
 * @RestController注解相当于@ResponseBody ＋ @Controller合在一起的作用
   1) 如果只是使用@RestController注解Controller，则Controller中的方法无法返回jsp页面，或者html，配置的视图解析器 InternalResourceViewResolver不起作用，返回的内容就是Return 里的内容
   2) 如果需要返回到指定页面，则需要用 @Controller配合视图解析器InternalResourceViewResolver才行。如果需要返回JSON，XML或自定义mediaType内容到页面，则需要在对应的方法上加上@ResponseBody注解。
 * 
 * @author ouyangjun
 *
 */
@Api(tags="Demo Controller")
@RestController
@RequestMapping(value="/xm/demo")
public class DemoController {
	
	@Autowired
	private DemoService demoService;

	@ApiOperation(value="Test Hello World!方法", notes="Test")
	@RequestMapping(value = "/hello", method = RequestMethod.GET)
	public String helloMethod(){
		return demoService.helloMethod();
	}
	
	/**
	 * Fegin方式通信
	 * @return
	 */
	@ApiOperation(value="fegin通信Test、OAuth模块", notes="Test")
	@RequestMapping(value = "/fegin/hello", method = RequestMethod.GET)
	public String feginHello(){
		return demoService.feginHello();
	}
	
	/**
	 * ribbon方式通信
	 * @return
	 */
	@ApiOperation(value="ribbon通信Test、OAuth模块", notes="Test")
	@RequestMapping(value = "/ribbon/hello", method = RequestMethod.GET)
	public String ribbonHello(){
		return demoService.ribbonHello();
	}
	
}

   在xm-web-controller项目中新增一个DemoService.java接口，代码如下：

package com.maven.xm.web.service;

public interface DemoService {

	public String helloMethod();
	
	public String feginHello();
	
	public String ribbonHello();
	
}

   在xm-web-controller项目中新增一个DemoServiceImpl.java接口实现类，代码如下：

package com.maven.xm.web.service.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import com.maven.xm.oauth.api.IDemoApi;
import com.maven.xm.web.service.DemoService;

@Service
public class DemoServiceImpl implements DemoService {

	@Autowired
        RestTemplate restTemplate;
	
	/**
	 * 引入其它微服务暴露出来的api接口
	 */
	@Autowired
	private IDemoApi iDemoApi;
	
	@Override
	public String helloMethod() {
		return "Hello Spring Cloud!";
	}

	@Override
	public String feginHello() {
		return iDemoApi.hello();
	}

	@Override
	public String ribbonHello() {
		return restTemplate.getForObject("http://module-oauth-server/demo/hello",String.class);
	}

}

四）原先启动的应用不要停，如已停止原先应用，先重新启动原先两个模块，再启动WebApplication微服务

      xm-web-controller服务访问，在浏览器中输入：http://localhost:8762/xm/demo/hello，界面如下：

      Fegin通信方式，在浏览器中输入：http://localhost:8762/xm/demo/fegin/hello，界面展示如下：

     ribbon通信方式，在浏览器中输入：http://localhost:8762/xm/demo/ribbon/hello，界面展示如下：

注意：在项目开发过程中，个人喜欢用fegin模式通信，代码方便简洁。

源码下载地址: https://gitee.com/ouyangjun_xm/springcloud/attach_files下chapter-three.rar压缩包

                      码云账户: [email protected]     密码: [email protected]

                      请勿恶意操作，谢谢！

本文说明：该文章属于原创，如需转载，请标明文章转载来源