微服务demo（三）nacosfeign

一、feign使用

1、集成方法

1.1、pom

consumer添加依赖

 <dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId><version>2.2.6.RELEASE</version></dependency>

1.2、启动类

consumer启动类加上@EnableFeignClients注解，即开启feign；

1.3、consumer调用provider：

编写一个中间service，consumer调用service，service调用provider。这个service类头加@FeignClient注解：

@FeignClient(value = "my-service",path = "/myProvider")

（1）value：provider配置文件中的spring.application.name，

    注意这里的value值不分大小写，my-service和MY-SERVICE都可以。

（2）path：如果provider在配置文件里面配置了server.context-path，FeignClient就需要指明path。

2、调用方法

上面提到的service，关于service调用provider传参的问题：

2.1、无参调用

post、get请求都可以

2.2、非对象参数

如Integer、String等，适用于get请求。

service方法上需要加@RequestParam注解，且括号中一定要有值(参数的别名)和被调用方provider的参数名保持一致，被调用方可加@RequestParam也可不加；

2.3、对象参数

javaBean，map，list等，只适用于post请求。

被调用方provider加@RequestBody注解，调用方service的方法可加可不加；

2.4、header头部参数：

provider和service方法上都使用@RequestHeader注解，且value指明参数别名。

二、集成demo

1、初版

1.1、父pom

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.demo.nacos</groupId><artifactId>nacos-demo</artifactId><version>0.0.1-SNAPSHOT</version><name>nacos-demo</name><packaging>pom</packaging><!-- springBoot --><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.0.4.RELEASE</version></parent><!-- 模块说明：这里声明多个子模块 --><modules><module>provider</module><module>consumer</module><module>nacos-common</module></modules><!-- 版本说明：这里统一管理依赖的版本号 --><dependencyManagement><dependencies><!-- SpringCloud --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>Finchley.RELEASE</version></dependency><!-- SpringCloud Alibaba --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>2.1.0.RELEASE</version></dependency><!--服务注册--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId><version>0.2.2.RELEASE</version></dependency><!-- nacos 注册中心客户端 --><!--        <dependency>--><!--            <groupId>com.alibaba.cloud</groupId>--><!--            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>--><!--            <version>2.1.0.RELEASE</version>--><!--        </dependency>--><!--集中配置--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId><version>2.1.0.RELEASE</version></dependency></dependencies></dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><!--nocas必须在web环境下--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

1.2、provider：

（1）pom：

 <parent><artifactId>nacos-demo</artifactId><groupId>com.demo.nacos</groupId><version>0.0.1-SNAPSHOT</version></parent><dependencies><dependency><groupId>com.demo.nacos</groupId><artifactId>nacos-common</artifactId><version>0.0.1-SNAPSHOT</version></dependency><!-- SpringCloud --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId></dependency><!-- SpringCloud Alibaba --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId></dependency><!--服务注册--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--集中配置--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency></dependencies>

（2）bootstrap：

spring:application:name: my-servicecloud:compatibility-verifier:enabled: falsenacos:#服务注册discovery:server-addr: xxx.xx.xxx:8848#配置中心config:server-addr: xxx.xx.xxx:8848group: wtyyprofiles:active: prod
server:port: 1111servlet:context-path: /myProvider

 （3）启动类：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@SpringBootApplication
@EnableDiscoveryClient
public class ProviderApplication {public static void main(String[] args) {SpringApplication.run(ProviderApplication.class, args);}
}

（4）controller接口

import com.demo.nacos.common.dto.UserDTO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.*;import javax.servlet.http.HttpServletRequest;@RestController
@RequestMapping("/configTest")
//刷新配置
@RefreshScope
public class ProviderTestController {@Value("${user.text}")private String userText;private static Logger logger = LoggerFactory.getLogger(ProviderTestController.class);/*** 1、无参 无返回* @param request* @return* @throws InterruptedException*/@GetMapping("/hanNoParam")public void getUserText(HttpServletRequest request) throws InterruptedException {logger.info("调用无参接口");}/*** 2、有参* @return* @throws InterruptedException*/@GetMapping("/hanParams")public String hanParams(String userName) throws InterruptedException {logger.info("调用有参接口");return userName+":"+userText;}/*** 3、有参，对象参数* @return* @throws InterruptedException*/@PostMapping("/hanObjParams")public UserDTO hanObjParams(@RequestBody UserDTO userDTO) throws InterruptedException {logger.info("调用对象参数接口");return userDTO;}/*** 4、参数加header* @return* @throws InterruptedException*/@PostMapping("/hanParamsAndHeader")public String hanParamsAndHeader(@RequestBody UserDTO userDTO,@RequestHeader("token") String token) throws InterruptedException {logger.info("调用参数和header接口");return userDTO.getUserName()+"的token:"+token;}
}

 1.3、consumer：

（1）pom：

<parent><artifactId>nacos-demo</artifactId><groupId>com.demo.nacos</groupId><version>0.0.1-SNAPSHOT</version></parent><dependencies><dependency><groupId>com.demo.nacos</groupId><artifactId>nacos-common</artifactId><version>0.0.1-SNAPSHOT</version></dependency><!-- SpringCloud --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId></dependency><!-- SpringCloud Alibaba --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId></dependency><!--服务注册--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--集中配置--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId><version>2.2.6.RELEASE</version></dependency></dependencies>

（2） bootstrap：

spring:application:name: my-consumercloud:compatibility-verifier:enabled: falsenacos:#服务注册discovery:server-addr: xxx.xx.xxx:8848#配置中心config:server-addr: xxx.xx.xxx:8848group: wtyy
server:port: 2222servlet:context-path: /myConsumer

（3） 启动类：

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

（4） service：重点

import com.demo.nacos.common.dto.UserDTO;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;@FeignClient(value = "my-service",path = "/myProvider")
public interface NacosConfigTestService {@RequestMapping("/configTest/hanNoParam")void hanNoParam();@RequestMapping("/configTest/hanParams")String hanParams(@RequestParam("userName")String userName);@RequestMapping("/configTest/hanObjParams")UserDTO hanObjParams(@RequestBody UserDTO userDTO);@RequestMapping("/configTest/hanParamsAndHeader")String hanParamsAndHeader(@RequestBody UserDTO userDTO,@RequestHeader("token") String token);
}

（5） controler：

import com.demo.nacos.common.dto.UserDTO;
import com.demo.nacos.consumer.service.NacosConfigTestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;import javax.servlet.http.HttpServletRequest;@RestController
@RequestMapping("/consumerTest")
public class ConsumerTestController {@Autowiredprivate NacosConfigTestService nacosConfigTestService;@GetMapping("/hanNoParam")public void getTemp(HttpServletRequest request) throws InterruptedException {nacosConfigTestService.hanNoParam();}@GetMapping("/hanParams")public String hanParams(String userName) throws InterruptedException {return nacosConfigTestService.hanParams(userName);}@PostMapping("/hanObjParams")public UserDTO hanObjParams(@RequestBody UserDTO userDTO) throws InterruptedException {return nacosConfigTestService.hanObjParams(userDTO);}@PostMapping("/hanParamsAndHeader")public String hanParamsAndHeader(@RequestBody UserDTO userDTO,HttpServletRequest request) throws InterruptedException {String token = request.getHeader("token");return nacosConfigTestService.hanParamsAndHeader(userDTO,token);}
}

1.4、测试

分别启动provider、consumer，可以看到都注册到nacos上了：

（1）非对象参数

（2）对象参数

（3）对象参数&header

2、feign的继承特性

上面的代码有很多重复的地方，下面利用feign的继承特性进行抽取。