fallbackFactory（类似于断容器）与fallback方法
feign的注解@FeignClient：fallbackFactory与fallback方法不能同时使用，这个两个方法其实都类似于Hystrix的功能，当网络不通时返回默认的配置数据.
fallback方法的使用：
在入口文件开启feign注解功能。
@EnableFeignClients
@EnableEurekaClient
@SpringBootApplication
@EnableFeignClients
public class FeignApp {
public static void main(String[] args) {
SpringApplication.run(FeignApp.class, args);
}
}
2.写一个访问spring-boot-user服务的接口，同时在@FeignClient注解中使用fallback默认返回方法（断容器）
fallback=HystrixClientFallback.class
@FeignClient(name="spring-boot-user", fallback=HystrixClientFallback.class)
public interface UserFeignClient {
// 两个坑：1. @GetMapping不支持 2. @PathVariable得设置value
@RequestMapping(value="/simple/{id}", method=RequestMethod.GET)
public User findById(@PathVariable("id") Long id);
}
3.写HystrixClientFallback类，并继承UserFeignClient类，当网络不通或者访问失败时，返回固定/默认内容
@Component
public class HystrixClientFallback implements UserFeignClient{
@Override
public User findById(Long id) {
// TODO Auto-generated method stub
User user = new User();
user.setId(0L);
return user;
}
}
4.controller调用spring-boot-user服务的接口
@RestController
public class MovieController {
@Autowired
private UserFeignClient userFeignClient;
@GetMapping("/movie/{id}")
public User findById(@PathVariable("id") Long id) {
return this.userFeignClient.findById(id);
}
}
fallbackFactory方法的使用
1.入口文件引入feign注解
@EnableEurekaClient
@SpringBootApplication
@EnableFeignClients
public class FeignApp {
public static void main(String[] args) {
SpringApplication.run(FeignApp.class, args);
}
}
2.写feignClient客户端j,使用feignClient注解的fallbackFactory方法
@FeignClient(name="spring-boot-user", fallbackFactory=HystrixClientFallbackFactory.class)
public interface UserFeignClient {
// 两个坑：1. @GetMapping不支持 2. @PathVariable得设置value
@RequestMapping(value="/simple/{id}", method=RequestMethod.GET)
public User findById(@PathVariable("id") Long id);
}
3.写HystrixClientFallbackFactory类，和HystrixClientWithFallbackFactory类
HystrixClientWithFallbackFactory类继承UserFeignClient类
public interface HystrixClientWithFallbackFactory extends UserFeignClient {
}
HystrixClientFallbackFactory实现FallbackFactory类，并使用内部匿名方法类，继续UserFeignClient
@Component
public class HystrixClientFallbackFactory implements FallbackFactory<UserFeignClient> {
@Override
public UserFeignClient create(Throwable arg0) {
// TODO Auto-generated method stub
return new HystrixClientWithFallbackFactory() {
@Override
public User findById(Long id) {
// TODO Auto-generated method stub
User user = new User();
user.setId(-1L);
return user;
}
};
}
}
4controller调用UserFeignClient接口
@RestController
public class MovieController {
@Autowired
private UserFeignClient userFeignClient;
@GetMapping("/movie/{id}")
public User findById(@PathVariable("id") Long id) {
return this.userFeignClient.findById(id);
}
}
5调用
当开启spring-boot-user方法，返回数据
当关闭spring-boot-user服务时
