抛出异常的最佳做法,如果db中没有找到条目？
// CONTROLLER
public ActionResult Edit(int categoryId,int id)
{
Product target = Products.GetById(id);
if (target == null) throw new HttpException(404,"Product not found");
return View("Edit",target);
}
// REPOSITORY
public Product GetById(int id)
{
return context.Products.FirstOrDefault(x => x.productId == id);
}
要么
// CONTROLLER
public ActionResult Edit(int categoryId,int id)
{
return View("Edit",Products.GetById(id));
}
// REPOSITORY
public Product GetById(int id)
{
Product target = context.Products.FirstOrDefault(x => x.productId == id);
if (target == null) throw new HttpException(404,"Product not found with given id");
return target;
}
解决方法
不要从存储库中引发HttpException异常,这是抽象层次错误.如果您不想让您的存储库返回null,请执行以下操作：
// CONTROLLER
public ActionResult Edit(int categoryId,int id)
{
try {
Product target = Products.GetById(id);
}
catch(ProductRepositoryException e) {
throw new HttpException(404,"Product not found")
}
return View("Edit",target);
}
// REPOSITORY
public Product GetById(int id)
{
Product target = context.Products.FirstOrDefault(x => x.productId == id);
if (target == null) throw new ProductRepositoryException();
return target;
}
您的存储库不应该知道有关HTTP的任何信息,但您的控制器可以了解存储库.所以您从存储库中抛出存储库异常,并将其转换为控制器中的HTTP异常.
