#yyds干货盘点# springcloud整合feign实现服务负载均衡,断路器

Posted 2022-01-15 灰太狼_cxh

springcloud整合feign实现服务负载均衡,断路器

1.项目目录：

创建项目feign作为父类

2.代码实现：

父类依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.cxh</groupId>
    <artifactId>feign</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>feign</name>
    <description>Demo project for Spring Boot</description>
    <packaging>pom</packaging>
    <properties>
        <java.version>8</java.version>
        <spring-cloud-alibaba-dependencies.version>2021.1</spring-cloud-alibaba-dependencies.version>
        <spring-cloud-dependencies.version>2021.0.0</spring-cloud-dependencies.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>$spring-cloud-dependencies.version</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>$spring-cloud-alibaba-dependencies.version</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

创建module项目feign-client

添加依赖

<parent>
        <groupId>com.cxh</groupId>
        <artifactId>feign</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.cxh</groupId>
    <artifactId>feign-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>feign-client</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--服务注册-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>0.2.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

yml配置

server:
  port: 8001

spring:
  application:
    name: feign-client #服务名
  profiles:
    active: dev #环境设置
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 #nacos服务注册

控制器

@Slf4j
@RestController
public class ClientController 

    @Value("$server.port")
    private String port;

    @GetMapping("/add")
    public String add(Integer a, Integer b)
        Integer c = a + b;
        log.info("端口计算：" + port + ":" + c);
        return "端口计算：" + port + ":" + c;
    

启动器添加注解

@SpringBootApplication
@EnableDiscoveryClient
public class FeignClientApplication 

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

创建module项目feign-client2，这个跟feign-client是一样的，只是yml配置改了个端口，其他代码一样，用于测试负载均衡

server:
  port: 8002

spring:
  application:
    name: feign-client #服务名
  profiles:
    active: dev #环境设置
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 #nacos服务注册

创建module项目feign-consumer

添加依赖

<parent>
        <groupId>com.cxh</groupId>
        <artifactId>feign</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.cxh</groupId>
    <artifactId>feign-consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>feign-consumer</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--服务注册-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>0.2.1.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
            <version>2.2.10.RELEASE</version>
        </dependency>

    </dependencies>

yml配置

server:
  port: 8003

spring:
  application:
    name: feign-consumer #服务名
  profiles:
    active: dev #环境设置
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 #nacos服务注册

  main:
    allow-bean-definition-overriding: true

#开启熔断器
feign:
  circuitbreaker:
    enabled: true

控制器

@Slf4j
@RestController
public class ConsumerController 

    @Autowired
    private ClientService clientService;

    @GetMapping("/add")
    public String add() 
        return clientService.add(10, 20);
    

@FeignClient(value = "feign-client", fallback = ClientServiceHystrix.class)
public interface ClientService 

    @GetMapping("/add")
    String add(@RequestParam(value = "a") Integer a, @RequestParam(value = "b") Integer b);

@Component
public class ClientServiceHystrix implements ClientService 
    @Override
    public String add(Integer a, Integer b) 
        return "调用失败";
    

启动器添加注解

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class FeignConsumerApplication 

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

3.实现效果：

启动nacos后，再启动feign-client, feign-client2, feign-consumer项目，打开浏览器​​http://localhost:8003/add​​

第一次请求：

端口计算：8001:30

第二次请求：

端口计算：8002:30

关闭feign-client, feign-client2项目后第三请求: 

调用失败