Spring Cloud 深度解析：构建高可用微服务架构实践指南

<!-- 引入Spring Cloud Alibaba依赖 -->  
<dependencyManagement>  <dependencies>  <dependency>  <groupId>com.alibaba.cloud</groupId>  <artifactId>spring-cloud-alibaba-dependencies</artifactId>  <version>2022.0.0.0</version>  <type>pom</type>  <scope>import</scope>  </dependency>  </dependencies>  
</dependencyManagement>  <dependencies>  <!-- Nacos服务发现与配置中心 -->  <dependency>  <groupId>com.alibaba.cloud</groupId>  <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>  </dependency>  <dependency>  <groupId>com.alibaba.cloud</groupId>  <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>  </dependency>  <!-- Sentinel流量防护 -->  <dependency>  <groupId>com.alibaba.cloud</groupId>  <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>  </dependency>  
</dependencies>  

@SpringBootApplication  
@EnableDiscoveryClient // 启用服务发现  
public class ProductServiceApplication {  public static void main(String[] args) {  SpringApplication.run(ProductServiceApplication.class, args);  }  
}  

@RestController  
@RequestMapping("/orders")  
public class OrderController {  @Autowired  private DiscoveryClient discoveryClient;  @GetMapping("/services")  public List<String> getServices() {  return discoveryClient.getServices(); // 获取所有注册服务名  }  
}  

@FeignClient(name = "product-service", path = "/products") // 指定服务名与路径  
public interface ProductClient {  @GetMapping("/{id}")  Product getProduct(@PathVariable("id") Long id); // 声明远程方法  
}  

@RestController  
@RequestMapping("/orders")  
public class OrderController {  @Autowired  private ProductClient productClient;  @GetMapping("/{id}")  public Order getOrder(@PathVariable Long id) {  Order order = orderService.getOrder(id);  // 调用商品服务获取商品信息  Product product = productClient.getProduct(order.getProductId());  order.setProduct(product);  return order;  }  
}  

@GetMapping("/product/{id}")  
@SentinelResource(  value = "getProduct",          // 资源名  blockHandler = "handleBlock",   // 流控处理方法  fallback = "getProductFallback" // 降级处理方法  
)  
public Product getProduct(@PathVariable Long id) {  return productService.getProduct(id);  
}  // 流控处理（BlockException）  
public Product handleBlock(Long id, BlockException ex) {  return new Product(id, "系统繁忙，请稍后再试", 0.0);  
}  // 异常降级（Throwable）  
public Product getProductFallback(Long id, Throwable e) {  return new Product(id, "降级商品", 0.0);  
}  // 初始化流控规则（QPS阈值10）  
@PostConstruct  
public void initFlowRules() {  FlowRule rule = new FlowRule();  rule.setResource("getProduct");  rule.setGrade(RuleConstant.FLOW_GRADE_QPS);  rule.setCount(10);  FlowRuleManager.loadRules(Collections.singletonList(rule));  
}  

# application.yml  
spring:  cloud:  gateway:  routes:  - id: product_route          # 路由ID  uri: lb://product-service   # 负载均衡到服务实例  predicates:  - Path=/product/**        # 匹配路径规则  filters:  - StripPrefix=1           # 去除路径前缀  

@Component  
public class AuthFilter implements GlobalFilter, Ordered {  @Override  public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {  String token = exchange.getRequest().getHeaders().getFirst("Authorization");  if (StringUtils.isEmpty(token)) {  exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED); // 401未认证  return exchange.getResponse().setComplete();  }  if (!isValidToken(token)) {  exchange.getResponse().setStatusCode(HttpStatus.FORBIDDEN); // 403权限拒绝  return exchange.getResponse().setComplete();  }  return chain.filter(exchange); // 放行请求  }  private boolean isValidToken(String token) {  // 实现Token验证逻辑（如JWT解析）  return true;  }  @Override  public int getOrder() {  return Ordered.HIGHEST_PRECEDENCE; // 最高优先级  }  
}  

# bootstrap.yml（配置优先级高于application.yml）  
spring:  application:  name: order-service       # 应用名（与Nacos配置分组关联）  profiles:  active: dev              # 激活开发环境配置  cloud:  nacos:  config:  server-addr: 127.0.0.1:8848   # Nacos服务器地址  file-extension: yaml          # 配置文件格式  namespace: 9e8e3e7a-...       # 环境隔离命名空间  group: DEV_GROUP              # 配置分组  

@RestController  
@RefreshScope // 开启配置热更新  
public class ConfigController {  @Value("${app.config.title:默认标题}")  private String title;  @GetMapping("/config")  public String getConfig() {  return title; // 修改Nacos配置后自动刷新  }  
}  

@RestController  
public class OrderController {  @Autowired  private OrderService orderService;  @PostMapping("/create")  @GlobalTransactional // 声明全局事务  public String createOrder(@RequestBody OrderDTO orderDTO) {  // 1. 创建订单  orderService.createOrder(orderDTO);  // 2. 扣减库存（远程调用）  storageFeignService.deduct(orderDTO.getProductId(), orderDTO.getCount());  // 3. 扣减账户余额（远程调用）  accountFeignService.debit(orderDTO.getUserId(), orderDTO.getMoney());  return "success";  }  
}  

# file.conf  
service {  vgroupMapping.default_tx_group = "default" # 事务分组  
}  store {  mode = "db"  db {  datasource = "druid"  url = "jdbc:mysql://127.0.0.1:3306/seata" # Seata事务日志数据库  user = "root"  password = "123456"  }  
}  

# Feign超时配置（连接超时5s，读取超时10s）  
feign:  client:  config:  default:  connectTimeout: 5000  readTimeout: 10000  # Ribbon超时配置  
ribbon:  ReadTimeout: 10000  ConnectTimeout: 5000  

mvn -Pnative spring-boot:build-image  

@HttpExchange(url = "/products", accept = "application/json")  
public interface ProductClient {  @GetExchange("/{id}")  Product getProduct(@PathVariable Long id);  
}  

@ReactiveFeignClient(name = "product-service")  
public interface ReactiveProductClient {  @GetMapping("/{id}")  Mono<Product> getProduct(@PathVariable Long id);  
}