SpringCloud的降级和熔断使用案例

实体类Dept implements Serializable// entity --orm--- db_table

import java.io.Serializable;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import lombok.experimental.Accessors;


@NoArgsConstructor
//@AllArgsConstructor
@Data
@Accessors(chain=true)
//存取器。通过该注解可以控制getter和setter方法的形式。
public class Dept implements Serializable// entity --orm--- db_table
{
  private Long  deptno; // 主键
  private String  dname; // 部门名称
  private String  db_source;// 来自那个数据库，因为微服务架构可以一个服务对应一个数据库，同一个信息被存储到不同数据库
  
  public Dept(String dname)
  {
    super();
    this.dname = dname;
  }


}

服务层-Controller服务层DeptClientService

import java.util.List;

import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.atguigu.springcloud.entities.Dept;
/**
 * @Description: 修改microservicecloud-api工程，根据已经有的DeptClientService接口
新建
一个实现了FallbackFactory接口的类DeptClientServiceFallbackFactory
 */
@FeignClient(value = "MICROSERVICECLOUD-DEPT",fallbackFactory=DeptClientServiceFallbackFactory.class)
public interface DeptClientService
{
  @RequestMapping(value = "/dept/get/{id}", method = RequestMethod.GET)
  public Dept get(@PathVariable("id") long id);

  @RequestMapping(value = "/dept/list", method = RequestMethod.GET)
  public List<Dept> list();

  @RequestMapping(value = "/dept/add", method = RequestMethod.POST)
  public boolean add(Dept dept);
}

DeptClientServiceFallbackFactory  熔断降级服务

import java.util.List;
import org.springframework.stereotype.Component;
import com.atguigu.springcloud.entities.Dept;
import feign.hystrix.FallbackFactory;

@Component // 不要忘记添加，不要忘记添加
public class DeptClientServiceFallbackFactory implements FallbackFactory<DeptClientService>
{
  @Override
  public DeptClientService create(Throwable throwable)
  {
    return new DeptClientService() {
      @Override
      public Dept get(long id)
      {
        return new Dept().setDeptno(id).setDname("该ID：" + id + "没有没有对应的信息,Consumer客户端提供的降级信息,此刻服务Provider已经关闭")
            .setDb_source("no this database in MySQL");
      }

      @Override
      public List<Dept> list()
      {
        return null;
      }

      @Override
      public boolean add(Dept dept)
      {
        return false;
      }
    };
  }
}