【设计模式】JAVA Design Patterns——Aggregator Microservices（聚合器微服务模式）

public class Product {
  private String title;
  private int productInventories;
  // getters and setters ->
  ...
}

@RestController
public class Aggregator {
 
  @Resource
  private ProductInformationClient informationClient;
 
  @Resource
  private ProductInventoryClient inventoryClient;
 
  @RequestMapping(path = "/product", method = RequestMethod.GET)
  public Product getProduct() {
 
    var product = new Product();
    var productTitle = informationClient.getProductTitle();
    var productInventory = inventoryClient.getProductInventories();
 
    //Fallback to error message
    product.setTitle(requireNonNullElse(productTitle, "Error: Fetching Product Title Failed"));
 
    //Fallback to default error inventory
    product.setProductInventories(requireNonNullElse(productInventory, -1));
 
    return product;
  }
}

@RestController
public class InformationController {
  @RequestMapping(value = "/information", method = RequestMethod.GET)
  public String getProductTitle() {
    return "The Product Title.";
  }
}

curl http://localhost:端口号/product
{"title":"The Product Title.","productInventories":5}