面向对象设计：如何基于职责原则合理放置新函数

public class Order 
{
   private OrderStatus status; // 订单状态
   // ... 其他订单属性

   public ProcessingResult Place() { 
       // 执行下订单的逻辑，例如：
       // 验证订单、扣除库存、生成支付请求等
       if (isValid()) {
           this.status = OrderStatus.PLACED;
           System.out.println("订单已成功放置。");
           return new ProcessingResult(true, "订单放置成功");
       } else {
           System.err.println("订单验证失败。");
           return new ProcessingResult(false, "订单验证失败");
       }
   }

   private boolean isValid() {
       // 订单验证逻辑
       return true; // 简化示例
   }
}

public class ProcessingResult {
    private boolean success;
    private String message;

    public ProcessingResult(boolean success, String message) {
        this.success = success;
        this.message = message;
    }
    // ... getter methods
}

public class Parameters {
    private String name;
    private int value;

    public Parameters(String name, int value) {
        this.name = name;
        this.value = value;
    }
    // ... getter methods
}

public class B {
    private String internalName;
    private int internalValue;

    private B(String internalName, int internalValue) {
        this.internalName = internalName;
        this.internalValue = internalValue;
    }

    public static B Create(Parameters parameters) {
        // 根据参数创建B的实例
        if (parameters.getValue() > 0) {
            return new B(parameters.getName() + "_processed", parameters.getValue() * 2);
        } else {
            throw new IllegalArgumentException("Invalid parameters for B creation.");
        }
    }
    // ... getter methods
}

public class FooUseCaseParameters {
    private String inputData;
    // ... getter methods
}

public class FooUseCaseResult {
    private String outputData;
    // ... getter methods
}

public class FooUseCase {
    // 可能依赖于其他服务或仓储
    // private SomeService someService; 

    public FooUseCaseResult Execute(FooUseCaseParameters parameters) {
        System.out.println("执行用例：" + parameters.getInputData());
        // 1. 验证参数
        // 2. 调用领域服务或仓储获取/修改数据
        // 3. 组合结果
        String processedData = parameters.getInputData().toUpperCase() + "_PROCESSED";
        return new FooUseCaseResult(processedData);
    }
}