springcloud之自定义简易消费服务组件

  org.springframework.boot
  spring-boot-starter-web


  org.springframework.cloud
  spring-cloud-starter-eureka

@Service
public class UserService implements UserInterface {

  @Autowired
  protected RestTemplate restTemplate;

  @Override
  public MoRp> getUsers(MoRq rq) {
    return null;
  }

  @Override
  public String getMsg() {

    String str = restTemplate.getForObject("http://EUREKA-PROVIDER/msg", String.class);
    return str;
  }
}

@RestController
public class UserController {

  @Autowired
  private UserService userService;

  @GetMapping("/msg")
  public String getMsg(){

    return userService.getMsg();
  }
}

@SpringBootApplication
@EnableDiscoveryClient //消费客户端
public class EurekaConsumerRibbonApplication {

  @Bean 
  @LoadBalanced //负载均衡
  RestTemplate restTemplate(){
    return new RestTemplate();
  }
  
  public static void main(String[] args) {
    SpringApplication.run(EurekaConsumerRibbonApplication.class, args);
  }
}

/**
 * Created by shenniu on 2018/6
 * 

 * rest+eureka+自定义client端
 */
@Component
public class ShenniuBanlance {

  @Autowired
  private RestTemplate restTemplate;

  @Autowired
  private DiscoveryClient discoveryClient;

  /**
   * 服务真实地址 ConcurrentHashMap<"服务应用名称", ("真实接口ip", 被访问次数)>
   */
  public static ConcurrentHashMap> sericesMap = new ConcurrentHashMap<>();

  /**
   * 设置服务提供者信息到map
   */
  public void setServicesMap() {
    //获取所有服务提供者applicationName
    List appNames = discoveryClient.getServices();

    //存储真实地址到map
    for (String appName :
        appNames) {
      //获取某个服务提供者信息
      List instanceInfos = discoveryClient.getInstances(appName);
      if (instanceInfos.isEmpty()) {
        continue;
      }

      List services = new ArrayList<>();
      instanceInfos.forEach(b -> {
        MoService service = new MoService();
        //被访问次数
        service.setWatch(0L);
        //真实接口地址
        service.setUrl(b.getUri().toString());
        services.add(service);
      });

      //如果存在就更新
      sericesMap.put(appName.toLowerCase(), services);
    }
  }

  /**
   * 根据app获取轮询方式选中后的service
   *
   * @param appName
   * @return
   */
  public MoService choiceServiceByAppName(String appName) throws Exception {
    appName = appName.toLowerCase();
    //某种app的服务service集合
    List serviceMap = sericesMap.get(appName);
    if (serviceMap == null) {
      //初始化所有app服务
      setServicesMap();
      serviceMap = sericesMap.get(appName);
      if (serviceMap == null) {
        throw new Exception("未能找到" + appName + "相关服务");
      }
    }

    //筛选出被访问量最小的service 轮询的方式
    MoService moService = serviceMap.stream().min(
        Comparator.comparing(MoService::getWatch)
    ).get();

    //负载记录+1
    moService.setWatch(moService.getWatch() + 1);
    return moService;
  }

  /**
   * 自动刷新 服务提供者信息到map
   */
  @Scheduled(fixedDelay = 1000 * 10)
  public void refreshServicesMap() {
    setServicesMap();
  }

  /**
   * get请求服务获取返回数据
   *
   * @param appName   应用名称 ApplicationName
   * @param serviceName 服务名称 ServiceName
   * @param map     url上请求参数
   * @param tClass   返回类型
   * @param 
   * @return
   */
  public  T getServiceData(
      String appName, String serviceName,
      Map map,
      Class tClass) {
    T result = null;
    try {
      //筛选获取真实Service
      MoService service = choiceServiceByAppName(appName);

      //请求该service的url
      String apiUrl = service.getUrl() + "/" + serviceName;
      System.out.println(apiUrl);
      result = map != null ?
          restTemplate.getForObject(apiUrl, tClass, map) :
          restTemplate.getForObject(apiUrl, tClass);
    } catch (Exception ex) {
      ex.printStackTrace();
    }
    return result;
  }

  /**
   * Service信息
   */
  public class MoService {
    /**
     * 负载次数记录数
     */
    private Long watch;
    /**
     * 真实接口地址： http://xxx.com/api/add
     */
    private String url;

    public Long getWatch() {
      return watch;
    }

    public void setWatch(Long watch) {
      this.watch = watch;
    }

    public String getUrl() {
      return url;
    }

    public void setUrl(String url) {
      this.url = url;
    }
  }
}

@Override
  public String getMsg() {

    String str = banlance.getServiceData(
        "EUREKA-PROVIDER", "msg",
        null,
        String.class
    );
    return str;
  }

/**
   * 自动刷新 服务提供者信息到map 
   */
  @Scheduled(fixedDelay = 1000 * 10)
  public void refreshServicesMap() {
    setServicesMap();
  }