Cloud-Nacos服务治理-Feign服务调用

构建Cloud

父工程依赖

<?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><groupId>org.example</groupId><artifactId>cloud-demo2</artifactId><packaging>pom</packaging><version>1.0-SNAPSHOT</version><modules><module>common-api</module><module>user-service</module></modules><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.3.9.RELEASE</version><relativePath/></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>Hoxton.SR10</spring-cloud.version><mysql.version>8.0.27</mysql.version><mybatis.version>2.1.1</mybatis.version><junit.version>4.12</junit.version><log4j.version>1.2.17</log4j.version><lombok.version>1.16.18</lombok.version><spring.cloud.alibaba>2.2.5.RELEASE</spring.cloud.alibaba></properties><dependencyManagement><dependencies><!-- springCloud --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>${spring-cloud.version}</version><type>pom</type><scope>import</scope></dependency><!-- springCloudAlibaba --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>${spring.cloud.alibaba}</version><type>pom</type><scope>import</scope></dependency><!-- mysql驱动 --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>${mysql.version}</version></dependency><!--mybatis--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>${mybatis.version}</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version></dependency><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>${log4j.version}</version></dependency></dependencies></dependencyManagement><dependencies><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>${lombok.version}</version><optional>true</optional></dependency></dependencies></project>

构建公共模块

构建user-service(生产者)

依赖

  <dependencies><!--nacos客户端依赖--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--Eureka客户端-->
<!--        <dependency>-->
<!--            <groupId>org.springframework.cloud</groupId>-->
<!--            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>-->
<!--        </dependency>--><dependency><groupId>org.example</groupId><artifactId>common-api</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><!--mybatis--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId></dependency></dependencies><build><finalName>userserver</finalName><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build>

启动类

@SpringBootApplication
@MapperScan("com.example.userservice.mapper")
//@MapperScan({"com.example.userservice.mapper", "com.example.anotherpackage.mapper"})
public class UserServiceApplication {public static void main(String[] args) {SpringApplication.run(UserServiceApplication.class, args);}
}

mapper

public interface UserMapper {@Select("select * from tb_user where id = #{id}")User findById(Long id);
}

service

public interface UserService {User queryById(Long id);
}

impl

@Service
public class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;public User queryById(Long id) {return userMapper.findById(id);}
}

controller

@RestController
@RequestMapping("/user")
@Slf4j
public class UserController {@Autowiredprivate UserService userService;@Value("${server.port}")private String serverPort;@GetMapping("/serverport")public String serverport(){return serverPort;}@GetMapping("/{id}")public User queryById(@PathVariable("id") Long id) {User user = userService.queryById(id);user.setServerPort(serverPort);return user;}
}

application.yml

server:port: 8081
spring:application:name: user-servicedatasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://xxxxxx:3306/cloud-user?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&serverTimezone=GMT%2B8&useCursorFetch=trueusername: xxxxxpassword: xxxxxxx
#默认就是8848cloud:nacos:server-addr: localhost:8848#redis:#port: 6379#database: 0#password: 1111111111111#ssl: false#####################################################redis 集群环境配置#cluster:#  nodes: 127.0.0.1:7001,127.0.0.1:7002,127.0.0.1:7003#  commandTimeout: 5000
mybatis:type-aliases-package: com.example.userservice.pojoconfiguration:map-underscore-to-camel-case: true
logging:level:com.example.userservice.mapper: debug
#eureka:
#  client:
#    #表示是否将自己注册进EurekaServer默认为true
#    register-with-eureka: true
#    #是否从EurekaServer抓取已有的注册信息默认true 单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
#    fetchRegistry: true
#    service-url:
#      defaultZone: http://localhost:7001/eureka

构建order-service(消费者)

依赖

 <dependencies><!--nacos客户端依赖--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--Eureka客户端--><!--        <dependency>--><!--            <groupId>org.springframework.cloud</groupId>--><!--            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>--><!--        </dependency>--><dependency><groupId>org.example</groupId><artifactId>common-api</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><!--mybatis--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId></dependency></dependencies><build><finalName>orderserver</finalName><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build>

启动类

@MapperScan("com.example.orderservice.mapper")
@SpringBootApplication
public class OrderApplication {public static void main(String[] args) {SpringApplication.run(OrderApplication.class, args);}@Bean@LoadBalanced//默认用的Ribbon的轮询策略public RestTemplate restTemplate(){return new RestTemplate();}//    @Bean
//    public IRule randomRule(){
//        return new RandomRule();
//    }}

mapper

public interface OrderMapper {@Select("select * from tb_order where id = #{id}")Order findById(Long id);
}

service

public interface OrderService {Order queryOrderById(Long orderId);
}

impl

@Service
public class OrderServiceImpl implements OrderService {@Autowiredprivate OrderMapper orderMapper;@Autowiredprivate RestTemplate restTemplate;public Order queryOrderById(Long orderId) {// 1.查询订单Order order = orderMapper.findById(orderId);// 2.利用RestTemplate发起http请求，查询用户// 2.1.url路径String url = "http://user-service/user/" + order.getUserId();// 2.2.发送http请求，实现远程调用User user = restTemplate.getForObject(url, User.class);// 3.封装user到Orderorder.setUser(user);// 4.返回return order;}
}

控制器

@RestController
@RequestMapping("/order")
public class OrderController {@Autowiredprivate OrderService orderService;@GetMapping("{orderId}")public Order queryOrderByUserId(@PathVariable("orderId") Long orderId) {// 根据id查询订单并返回return orderService.queryOrderById(orderId);}
}

application.yml

server:port: 80
spring:application:name: order-servicedatasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://xxxxxx:3306/cloud-order?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&serverTimezone=GMT%2B8&useCursorFetch=trueusername: xxxxxpassword: xxxxxx
#默认就是8848cloud:nacos:server-addr: localhost:8848#redis:#port: 6379#database: 0#password: 1111111111111#ssl: false#####################################################redis 集群环境配置#cluster:#  nodes: 127.0.0.1:7001,127.0.0.1:7002,127.0.0.1:7003#  commandTimeout: 5000
mybatis:type-aliases-package: com.example.orderservice.pojoconfiguration:map-underscore-to-camel-case: true
logging:level:com.example.userservice.mapper: debug
#将服务注册到Eureka
#eureka:
#  client:
#    #表示是否将自己注册进EurekaServer默认为true
#    register-with-eureka: true
#    #是否从EurekaServer抓取已有的注册信息默认true 单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
#    fetchRegistry: true
#    service-url:
#      defaultZone: http://localhost:7001/eureka# 全局配置
ribbon:NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RoundRobinRule# 特定服务配置
user-service:ribbon:NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule

勾下启动下再去掉

Nacos安装

GitHub主页：GitHub - alibaba/nacos: an easy-to-use dynamic service discovery, configuration and service management platform for building cloud native applications.an easy-to-use dynamic service discovery, configuration and service management platform for building cloud native applications. - alibaba/nacoshttps://github.com/alibaba/nacos

GitHub的Release下载页：Releases · alibaba/nacos · GitHuban easy-to-use dynamic service discovery, configuration and service management platform for building cloud native applications. - Releases · alibaba/nacoshttps://github.com/alibaba/nacos/releases

此版本用例1.4.1

Release 1.4.1 (Jan 15, 2021) · alibaba/nacos · GitHuban easy-to-use dynamic service discovery, configuration and service management platform for building cloud native applications. - Release 1.4.1 (Jan 15, 2021) · alibaba/nacoshttps://github.com/alibaba/nacos/releases/tag/1.4.1

单机启动

startup.cmd -m standalone

http://localhost:8848/nacos/index.html

访问 localhost:8848/nacos/index.html 账密 nacos

这样Nacos服务端就启动了

Nacos服务注册

且一样有Ribbon的负载均衡

Nacos服务多级存储模型

点击详情

配置服务集群

例如:我想在将userservice 8081 配置称SH 将8082和8083配置成HZ

那么现在我希望orderserver访问HZ的集群

这样的话 orderService会不会默认先访问HZ的集群

发现并没有还是3个都轮询访问原因在于Ribbon

重启orderservice

发现只会访问8082和8083 而且是随机的此时我将8082和8083两个服务停掉就会访问8081 看样子集群配置是个优先的选项但是当集群无法访问会自动切换到跨集群

Nacos权重设置

默认都是1 随机访问可以在0到1之间设置

如果我将8083设置成0.1

因为现在消费者也是HZ集群

明显现在调用大部分都是8082

如果设置成0 那么就不会被访问有什么好处呢??比如服务器维护 nice

Nacos环境隔离

Nacos的服务存储和数据存储的最外层namespace

namespace-->group--->服务--->集群-->实例

下面新建个命名空间

如何将服务放到自定义的命名空间里需要代码层面的配置

重启

那么这样会产生什么效果呢????

无法访问了也就是说在不同的namespace下无法访问

Nacos的临时实例和非临时实例

临时实例采用心跳向Nacos汇报挂了挂了会推送给消费者意思不健康了并且会马上剔除

非临时实例是Nacos主动询问挂了会推送给消费者意思不健康了不会剔除(除非你在Nacos管理页面手动删除)而是等待修复完成

如何注册非临时实例(默认都是临时实例)

Nacos统一配置管理

这里涉及一个Boot启动读取配置文件的优先级问题因为原先Nacos的配置是保存在application.yml中的,那么现在需要Nacos来管理配置文件, 那前提是不是需要知道Nacos配置的服务器地址在哪里,不知道怎么从nacos上读配置文件

如下图因此建议将Nacos的配置放在bootstrao.yml中

引入Naocis配置管理客户端的依赖

<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>

userService和orderService都引入

配置时注意缩进

我这里就把application.yml全部注释了

理论讲 bootstarp里配置的application可以删除当然可以不删但别不一样不然覆盖了

我这里整个注释了就完全按Nacos上配置的来

Nacos配置热更新

Nacos配置共享

Feign调用

首先在调用方导入Feign依赖

启动类加上@EnableFeignClients

原先是通过restTemplate

下面用Feign的方式声明feign调用接口

修改原先的调用方法编程体验不佳......

Feign本身就集成了负载均衡功能依赖中带了Ribbon

自定义Feign配置

主要是配置Feign调用日志级别

日志配置方式

这样配置没成功

用配置类这个类上不要加@Configuration

Feign性能优化

Feign使用最佳实践

这种方式Spring官方不推荐会造成紧耦合 API成面形成了紧耦合

也存在问题就是会把用不到的也引入进来

方式二的实现

依赖

这也有点麻烦要把实体类转掉可以把feign-api和common模块合并

@Autowired
private UserClient userClient;

这个也肯定用不了了那么就用@Bean 没试过试试呗