微服务springcloud—使用Zuul聚合微服务

系统管理员 2022-04-18 02:54 599阅读 0赞

# 使用Zuul聚合微服务 #

1.复制项目microservice-gateway-zuul。将ArtifactId修改为microservice-gateway-zuul-aggregation。  
2.修改启动类ZuulApplication：

@SpringBootApplication
    @EnableZuulProxy
    public class ZuulApplication { 
        public static void main(String[] args) { 
            SpringApplication.run(ZuulApplication.class, args);
        }
    
        @Bean
        @LoadBalanced
        public RestTemplate restTemplate() { 
            return new RestTemplate();
        }
    }

3.创建实体类

public class User { 
        private Long id;
        private String username;
        private String name;
        private Integer age;
        private BigDecimal balance;
    
        public Long getId() { 
            return id;
        }
    
        public void setId(Long id) { 
            this.id = id;
        }
    
        public String getUsername() { 
            return username;
        }
    
        public void setUsername(String username) { 
            this.username = username;
        }
    
        public String getName() { 
            return name;
        }
    
        public void setName(String name) { 
            this.name = name;
        }
    
        public Integer getAge() { 
            return age;
        }
    
        public void setAge(Integer age) { 
            this.age = age;
        }
    
        public BigDecimal getBalance() { 
            return balance;
        }
    
        public void setBalance(BigDecimal balance) { 
            this.balance = balance;
        }
    }

4.创建java类，名为AggregationService：

@Service
    public class AggregationService { 
        @Autowired
        private RestTemplate restTemplate;
    
        @HystrixCommand(fallbackMethod = "fallback")
        public Observable<User> getUserById(Long id) { 
            //创建一个被观察者
            return Observable.create(observer -> { 
               //创建用户为服务的/{id}端点
               User user = restTemplate.getForObject("http://users/{id}", User.class, id);
               observer.onNext(user);
               observer.onCompleted();
            });
        }
    
       @HystrixCommand(fallbackMethod = "fallback")
       public Observable<User> getMovieUserByUserId (Long id){ 
            return Observable.create(observer -> { 
               //请求电影微服务的/user/{id}端点
               User movieUser = restTemplate.getForObject("Http://movie/user/{id}",User.class, id);
               observer.onNext(movieUser);
               observer.onCompleted();
            });
       }
    
       public User fallback(Long id){ 
            User user = new User();
            user.setId(-1L);
            return user;
       }
    }

5.创建Controller，在Controller中聚合多个请求

@RestController
    public class AggregationController { 
        public static final Logger LOGGER = LoggerFactory.getLogger(ZuulApplication.class);
    
        @Autowired
        private AggregationService aggregationService;
    
        @GetMapping("/aggregate/{id}")
        public DeferredResult<HashMap<String, User>> aggregate(@PathVariable Long id){ 
            Observable<HashMap<String, User>> result = this.aggregateObservable(id);
            return this.toDeferredResult(result);
        }
    
        public Observable<HashMap<String, User>> aggregateObservable(Long id){ 
            //合并两个或者多个Observables发射出数据项，根据指定的函数变换他们
            return Observable.zip(
              this.aggregationService.getUserById(id),
              this.aggregationService.getMovieUserByUserId(id),
              (user, movieUser) -> { 
                  HashMap<String,User> map = Maps.newHashMap();
                  map.put("user", user);
                  map.put("movieUser", movieUser);
                  return map;
              }
            );
        }
        public DeferredResult<HashMap<String,User>> toDeferredResult(Observable<HashMap<String,User>>details){ 
            DeferredResult<HashMap<String,User>> result = new DeferredResult<>();
            //订阅
            details.subscribe(new Observer<HashMap<String,User>>() { 
                //@Override
                public void onCompleted(){ 
                    LOGGER.info("完成");
                }
    
                //@Override
                public void onError(Throwable throwable){ 
                    LOGGER.info("发生错误...", throwable);
                }
    
                //@Override
                public void onNext(HashMap<String,User>movieDetails){ 
                    result.setResult(movieDetails);
                }
            });
            return result;
        }
    }

# 测试一：微服务聚合测试 #

启动项目microservice-discovery-eureka。  
启动项目microservice-provider-user。  
启动项目microservice-consumer-movie。  
启动项目microservice-gateway-zuul-aggregation。  
访问http://localhost:8040/aggregate/1，可获得如下结果:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzQzOTQ5NA_size_16_color_FFFFFF_t_70]

# 测试二：Hystrix容错测试 #

1.在测试一的基础上，停止项目microservice-provider-user以及microservice-consumer-movie。  
2.访问http:localhost:8040/aggregate/1，可获得如下结果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzQzOTQ5NA_size_16_color_FFFFFF_t_70 1]  
说明fallback方法正常被触发，能够正常回退。

本文大部分内容转载自周立的《Spring Cloud与Docker微服务架构实战》

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzQzOTQ5NA_size_16_color_FFFFFF_t_70]: /images/20220418/0ba2b761f36a4732908011546b607701.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzQzOTQ5NA_size_16_color_FFFFFF_t_70 1]: /images/20220418/034b5ac00d754a0ca604c66be2fa8779.png