springcloud常用组件简明笔记

淩亂°似流年 2023-03-13 05:13 4阅读 0赞

### 1.springcloud依赖 ###

<properties>
    	<spring-cloud.version>Hoxton.SR4</spring-cloud.version>
    </properties>
    
    <dependencyManagement>
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-dependencies</artifactId>
    			<version>${spring-cloud.version}</version>
    			<type>pom</type>
    			<scope>import</scope>
    		</dependency>
    	</dependencies>
    </dependencyManagement>

### 2.注册中心 ###

1.pom依赖

<dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>

2.配置

eureka:
      instance:
        hostname: eureka8090.com
      client:
        # 是否将自己注册到eureka server
        register-with-eureka: false
        # 是否从eureka server获取注册信息
        fetch-registry: false
        serviceUrl:
          defaultZone: http://eureka8091.com:8091/eureka/, http://eureka8092.com:8092/eureka/

3.注解

@EnableEurekaServer

### 3.服务注册 ###

1.pom依赖

<dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>

2.配置

eureka:
      client:
        service-url:
          defaultZone: http://eureka8090.com:8090/eureka/, http://eureka8091.com:8091/eureka/, http://eureka8092.com:8092/eureka/

3.注解

@EnableEurekaClient

### 4.服务发现 ###

需要自己也注册。

1.pom依赖

spring-cloud-dependencies
    spring-cloud-starter-netflix-eureka-client

2.配置

eureka:
      client:
        service-url:
          defaultZone: http://localhost:8090/eureka

3.注解

@EnableEurekaClient
    @EnableDiscoveryClient

4.实现

DiscoveryClient client

### 5.负载均衡 ###

#### 第一种方式ribbon+RestTemplate ####

1.pom依赖

<dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
    </dependency>

2.配置

eureka:
      client:
        register-with-eureka: false
        serviceUrl:
          defaultZone: http://eureka8090.com:8090/eureka/, http://eureka8091.com:8091/eureka/, http://eureka8092.com:8092/eureka/

@Configuration
    public class RestConfig { 
    
        @Bean
        @LoadBalanced
        public RestTemplate getRestTemplate() { 
            return new RestTemplate();
        }
    }

3.注解

@EnableDiscoveryClient

4.调用RestTemplate

@Service
    public class RibbonService { 
        @Autowired
        private RestTemplate restTemplate;
    
        private static final String serviceName = "http://SERVICE-HI";
    
        public String hiService(String name) { 
            return restTemplate.getForObject(serviceName + "/hi/" + name, String.class);
        }
    }

#### 第二种方式Feign ####

1.pom依赖

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

2.配置

3.注解

@EnableFeignClients
    @EnableDiscoveryClient

4.服务接口

@FeignClient("SERVICE-HI")
    public interface ScheduleServiceHi { 
    
        @RequestMapping(value = "/hi/{name}")
        String sayHiFromClientOne(@PathVariable("name") String name);
    }

5.调用服务

@Autowired
    ScheduleServiceHi scheduleServiceHi;

### 6.服务熔断 ###

1.pom依赖

<dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
    </dependency>

2.配置

eureka.client

3.第一种方式ribbon+RestTemplate

@HystrixCommand(fallbackMethod = "hiError")
    public String getServiceHi(String name) { 
        return restTemplate.getForObject(URL + "/hi/" + name, String.class);
    }
    
    public String hiError(String name) { 
        return "sorry," + name + " there is an error";
    }
    
    @EnableHystrix
    @EnableDiscoveryClient

4.第二种方式feign

feign.hystrix.enabled: true
    
    实现调用服务的接口，放入fallback中
    
    在调用服务的接口注解上加上fallback
    @FeignClient(value = "SERVICE-HI", fallback = ScheduleServiceHiImpl.class)
    
    @EnableDiscoveryClient
    @EnableFeignClients