SpringCloud服務消費有哪幾種方式？

一、使用LoadBalancerClient
LoadBalancerClient接口的命名中，可以看出這是一個負載均衡客戶端的抽象定義，spring提供了一個實現
org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient
1、pom.xml
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.7.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.47</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- spring boot test -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
2、application.yml
server:
#服務端口號
port: 8080
spring:
application:
#服務名稱
name: vis-basic-report
thymeleaf:
cache: false
cloud:
consul:
host: 192.168.12.125
port: 8500
discovery:
#是否需要注冊到consul中
register: true
#服務地址直接為IP地址
hostname: 192.168.12.1
management:
endpoints:
web:
exposure:
include: '*'
3、啟動類
package com.wzl.springcloud.basic.report;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.Bean;
import com.netflix.hystrix.contrib.metrics.eventstream.HystrixMetricsStreamServlet;@SpringBootApplication
br/>@SpringBootApplication
public class ReportServerApplication {
public static void main(String[] args) {
SpringApplication.run(ReportServerApplication.class, args);
}
}
4、相關實現類
package com.wzl.springcloud.basic.report.service;
import java.util.List;
import com.wzl.springcloud.basic.report.vo.City;
import com.wzl.springcloud.basic.report.vo.WeatherResponse;
public interface WeatherReportService {
// 根據城市ID同步天氣
WeatherResponse getDataByCityId(String cityId);
// 根據城市name同步天氣
WeatherResponse getDataByCityName(String cityName);
// 獲取所有城市列表
List<City> getDataByCities();
}
package com.wzl.springcloud.basic.report.service.impl;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
import com.alibaba.fastjson.JSON;
import com.wzl.springcloud.basic.report.service.WeatherReportService;
import com.wzl.springcloud.basic.report.vo.City;
import com.wzl.springcloud.basic.report.vo.WeatherResponse;
/**

• LoadBalancer客戶端*/
  @Service
  br/>*/
  @Service
  br/>@Autowired
  

  @Override
  public WeatherResponse getDataByCityId(String cityId) {
  WeatherResponse weatherResponse = null;
  ServiceInstance serviceInstance = loadBalancer.choose("vis-basic-weather");
  String uri = serviceInstance.getUri().toString() + "/weather/cityId/" + cityId;
  // 調用服務接口來獲取
  ResponseEntity<String> respString = new RestTemplate().getForEntity(uri, String.class);
  // 判斷ResponseEntity的狀態碼是否為200，為200時取出strBody
  if (respString.getStatusCodeValue() == 200) {
  String jsonStr = respString.getBody();
  weatherResponse = JSON.parseObject(jsonStr, WeatherResponse.class);
  }
  return weatherResponse;}
  @Override
  br/>}
  @Override
  WeatherResponse weatherResponse = null;
  ServiceInstance serviceInstance = loadBalancer.choose("vis-basic-weather");
  String uri = serviceInstance.getUri().toString() + "/weather/cityName/" + cityName;
  // 調用服務接口來獲取
  ResponseEntity<String> respString = new RestTemplate().getForEntity(uri, String.class);
  // 判斷ResponseEntity的狀態碼是否為200，為200時取出strBody
  if (respString.getStatusCodeValue() == 200) {
  String jsonStr = respString.getBody();
  weatherResponse = JSON.parseObject(jsonStr, WeatherResponse.class);
  }
  return weatherResponse;
  }
  function(){ //AxiTrader返傭：www.kaifx.cn/broker/axitrader.html@Override
  br/>@Override
  List<City> cityList = null;
  ServiceInstance serviceInstance = loadBalancer.choose("vis-basic-city");
  String uri = serviceInstance.getUri().toString() + "/cities/getList";
  // 調用服務接口來獲取
  ResponseEntity<String> respString = new RestTemplate().getForEntity(uri, String.class);
  // 判斷ResponseEntity的狀態碼是否為200，為200時取出strBody
  if (respString.getStatusCodeValue() == 200) {
  String jsonStr = respString.getBody();
  cityList = JSON.parseArray(jsonStr, City.class);
  }
  return cityList;
  }
  }
  二、使用Ribbon
  Spring Cloud Ribbon是基于Netflix Ribbon實現的一套客戶端負載均衡的工具。它是一個基于HTTP和TCP的客戶端負載均衡器。它可以通過在客戶端中配置ribbonServerList來設置服務端列表去輪詢訪問以達到均衡負載的作用。
  1、pom.xml
  <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.1.7.RELEASE</version>
  <relativePath /> <!-- lookup parent from repository -->
  </parent>

  <dependencies>
  <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-actuator</artifactId>
  </dependency>
  <dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud</artifactId>
  </dependency>
  <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
  <dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>fastjson</artifactId>
  <version>1.2.47</version>
  </dependency>
  <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-thymeleaf</artifactId>
  </dependency>
  <dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
  </dependency>
  <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <!-- spring boot test -->
  <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-test</artifactId>
  <scope>test</scope>
  </dependency>
  </dependencies>
  2、application.yml
  server:
  #服務端口號
  port: 8080
  spring:
  application:
  #服務名稱
  name: vis-basic-report
  thymeleaf:
  cache: false
  cloud:
  consul:
  host: 192.168.12.125
  port: 8500
  discovery:
  #是否需要注冊到consul中
  register: true
  #服務地址直接為IP地址
  hostname: 192.168.12.1
  management:
  endpoints:
  web:
  exposure:
  include: '*'
  3、啟動類 & RestConfiguration
  package com.wzl.springcloud.basic.report;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.cloud.openfeign.EnableFeignClients;@SpringBootApplication
  br/>@SpringBootApplication
  public class ReportServerApplication {
  public static void main(String[] args) {
  SpringApplication.run(ReportServerApplication.class, args);
  }
  }
  package com.wzl.springcloud.basic.report.config;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.boot.web.client.RestTemplateBuilder;
  import org.springframework.cloud.client.loadbalancer.LoadBalanced;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.web.client.RestTemplate;@Configuration
  br/>@Configuration
  br/>@Autowired
  br/>@Bean
  public RestTemplate restTemplate() {
  return builder.build();}
  }
  @LoadBalanced注解表明這個restRemplate開啟負載均衡的功能，用LoadBalancerClient配置，并且會替換URL中的服務名稱為具體的IP地址
  br/>}
  }
  @LoadBalanced注解表明這個restRemplate開啟負載均衡的功能，用LoadBalancerClient配置，并且會替換URL中的服務名稱為具體的IP地址
  package com.wzl.springcloud.basic.report.service;
  import java.util.List;
  import com.wzl.springcloud.basic.report.vo.City;
  import com.wzl.springcloud.basic.report.vo.WeatherResponse;
  public interface WeatherReportService {
  // 根據城市ID同步天氣
  WeatherResponse getDataByCityId(String cityId);
  // 根據城市name同步天氣
  WeatherResponse getDataByCityName(String cityName);
  // 獲取所有城市列表
  List<City> getDataByCities();
  }
  package com.wzl.springcloud.basic.report.service.impl;
  import java.util.List;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.http.ResponseEntity;
  import org.springframework.stereotype.Service;
  import org.springframework.web.client.RestTemplate;
  import com.alibaba.fastjson.JSON;
  import com.wzl.springcloud.basic.report.service.WeatherReportService;
  import com.wzl.springcloud.basic.report.vo.City;
  import com.wzl.springcloud.basic.report.vo.WeatherResponse;
  /**

• Ribbon客戶端*/
  @Service
  br/>*/
  @Service
  br/>@Autowired
  private RestTemplate restTemplate;

  @Override
  public WeatherResponse getDataByCityId(String cityId) {
  WeatherResponse weatherResponse = null;
  String uri = "http://vis-basic-weather/weather/cityId/" + cityId;
  // 調用服務接口來獲取
  ResponseEntity<String> respString = restTemplate.getForEntity(uri, String.class);
  // 判斷ResponseEntity的狀態碼是否為200，為200時取出strBody
  if (respString.getStatusCodeValue() == 200) {
  String jsonStr = respString.getBody();
  weatherResponse = JSON.parseObject(jsonStr, WeatherResponse.class);
  }
  return weatherResponse;}
  @Override
  br/>}
  @Override
  WeatherResponse weatherResponse = null;
  String uri = "http://vis-basic-weather/weather/cityName/" + cityName;
  // 調用服務接口來獲取
  ResponseEntity<String> respString = restTemplate.getForEntity(uri, String.class);
  // 判斷ResponseEntity的狀態碼是否為200，為200時取出strBody
  if (respString.getStatusCodeValue() == 200) {
  String jsonStr = respString.getBody();
  weatherResponse = JSON.parseObject(jsonStr, WeatherResponse.class);
  }
  return weatherResponse;}
  @Override
  br/>}
  @Override
  List<City> cityList = null;
  String uri = "http://vis-basic-city/cities/getList";
  // 調用服務接口來獲取
  ResponseEntity<String> respString = restTemplate.getForEntity(uri, String.class);
  // 判斷ResponseEntity的狀態碼是否為200，為200時取出strBody
  if (respString.getStatusCodeValue() == 200) {
  String jsonStr = respString.getBody();
  cityList = JSON.parseArray(jsonStr, City.class);
  }
  return cityList;
  }
  }