说到AOP编程，可能大部分人是即熟悉又显得陌生。
AOP的作用就是横切关注点，然后将分离后的关注点以面的形式来呈现，这是概念性的说法，举个列子来说明吧。
比如说有个API接口处理场景是提交订单，在我们提交订单的时候，首先客户端要对用户提交的数据进行合法性验证，验证通过后，数据发送到服务端，因客户端一切操作都是不可信的，必然服务端在录入订单信息之前也需要对数据合法性进行验证。
针对上述问题我们可以这样子来编码
首先定义订单表单参数实体对象：
1 /// <summary>
2 /// Post表单参数
3 /// </summary>
4 public class FromOrderInfo
5 {
6 /// <summary>
7 /// 商品名称
8 /// </summary>
9 public string ShopName { get; set; }
10 /// <summary>
11 /// 手机号
12 /// </summary>
13 [ValidateMobile(ErrorMessage = "请输入正确格式的手机号")]//自定义验证规则
14 public string Mobile { get; set; }
15 /// <summary>
16 /// Address
17 /// </summary>
18 [ValidateMaxLength(20,ErrorMessage = "Address字符超过指定长度")]
19 public string Address { get; set; }
20 }
自定义验证如下：
1 /// <summary>
2 /// 验证字符长度是否超过指定长度
3 /// </summary>
4 public class ValidateMaxLengthAttribute : ValidationAttribute
5 {
6 private readonly int MaxLength;
7
8 public ValidateMaxLengthAttribute(int maxLength)
9 : base("{0}的字符太多了!")
10 {
11 MaxLength = maxLength;
12 }
13
14 protected override ValidationResult IsValid(object value, ValidationContext validationContext)
15 {
16 if (value != null)
17 {
18 string content = value.ToString();
19 int leng = StringTool.GetStringLength(content);
20 if (leng > MaxLength)
21 {
22 string errorMessage = FormatErrorMessage(validationContext.DisplayName);
23 return new ValidationResult(errorMessage);
24 }
25 }
26 return ValidationResult.Success;
27 }
28 }
29
30 /// <summary>
31 /// 验证手机号
32 /// </summary>
33 public class ValidateMobileAttribute : ValidationAttribute
34 {
35 public ValidateMobileAttribute()
36 : base("{0}应输入11位手机号!")
37 {
38 }
39 protected override ValidationResult IsValid(object value, ValidationContext validationContext)
40 {
41 if (value != null)
42 {
43 string content = value.ToString();
44 if (!RegexTool.IsMobile(content))
45 {
46 string errorMessage = FormatErrorMessage(validationContext.DisplayName);
47 return new ValidationResult(errorMessage);
48 }
49 }
50 return ValidationResult.Success;
51 }
52 }
订单API接口：
1 [CHKFormInput(typeof(FromOrderInfo))]
2 public HttpResponseMessage TestOrder([FromBody] FromInfo info)
3 {
4 var challengeMessage = new System.Net.Http.HttpResponseMessage(System.Net.HttpStatusCode.OK);
5
6 challengeMessage = new ResponseMessage<string>("json").Response("下单成功");
7 return challengeMessage;
8
9 }
10
11 /// <summary>
12 /// Post表单参数
13 /// </summary>
14 public class FromInfo
15 {
16 /// <summary>
17 /// Json数据对象
18 /// </summary>
19 public string JsonFormat { get; set; }
20 }
定义过滤器：
1 /// <summary>
2 /// 验证表单参数
3 /// </summary>
4 public class CHKFormInput : ActionFilterAttribute
5 {
6 private Type _type;
7 /// <summary>
8 /// 构造函数
9 /// </summary>
10 /// <param name="type">表单参数验证对象</param>
11 public CHKFormInput(Type type = null)
12 {
13 if (type != null)
14 {
15 this._type = type;
16 }
17 }
18 public override void OnActionExecuting(HttpActionContext actionContext)//执行action动作所需执行的操作
19 {
20 #region 检查表单参数是否合法
21 var challengeMessage = new System.Net.Http.HttpResponseMessage(System.Net.HttpStatusCode.OK);
22 ErrorResponse errorMsgConvertjson = new ErrorResponse();//返回错误信息string errorMsg = string.Empty;
23 try
24 {
25 if (actionContext == null)
26 {
27 throw new System.Web.Http.HttpResponseException(challengeMessage);
28 }
29 if (ProjectRequest.IsPost())//验证是否POST请求
30 {
31 var task = actionContext.Request.Content.ReadAsStreamAsync();
32 var content = string.Empty;
33 using (System.IO.Stream sm = task.Result)
34 {
35 if (sm != null)
36 {
37 sm.Seek(0, SeekOrigin.Begin);
38 int len = (int)sm.Length;
39 byte[] inputByts = new byte[len];
40 sm.Read(inputByts, 0, len);
41 sm.Close();
42 content = Encoding.UTF8.GetString(inputByts);
43 }
44 }
45 var m = JsonTool.JsonToEntity<FromInfo>(content);
46 var Json = Serializer.Deserialize(m.JsonFormat, _type);
47 new TryValidateModelTool().TryValidateModel(Json, ref errorMsg);
48 if(!string.IsNullOrEmpty(errorMsg))
49 {
50 errorMsgConvertjson.Message = errorMsg;
51 errorMsgConvertjson.State = CallBackServer.InputError;
52 challengeMessage = new ResponseMessage<ErrorResponse>("json").Response(errorMsgConvertjson);
53 actionContext.Response = challengeMessage;
54 }
55
56 }
57
58 }
59 catch (Exception ex)
60 {
61 }
62 finally
63 {
64 }
65 base.OnActionExecuting(actionContext);
66 #endregion
67 }
68 }
实体对像属性验证类：
1 /// <summary>
2 /// 利用特性验证实体对象参数合法性
3 /// </summary>
4 public class TryValidateModelTool : ApiController
5 {
6 /// <summary>
7 /// 利用特性验证实体对象参数合法性
8 /// </summary>
9 /// <param name="model">对象</param>
10 /// <param name="errorMsg">错误信息</param>
11 /// <returns></returns>
12 public bool TryValidateModel(object model, ref string errorMsg)
13 {
14 return TryValidateModel(model, null /* prefix */, ref errorMsg);
15 }
16
17
18
19
20 /// <summary>
21 /// 利用特性验证实体对象参数合法性
22 /// </summary>
23 /// <param name="model">对象</param>
24 /// <param name="errorMsg">错误信息</param>
25 /// <returns></returns>
26 public bool TryValidateModel(object model, string prefix, ref string errorMsg)
27 {
28 if (model == null)
29 {
30 throw new ArgumentNullException("model");
31 }
32
33 ModelMetadata metadata = ModelMetadataProviders.Current.GetMetadataForType(() => model, model.GetType());
34 var t = new ModelBindingExecutionContext(new HttpContextWrapper(HttpContext.Current), new System.Web.ModelBinding.ModelStateDictionary());
35 List<string> errorMsgList = new List<string>();
36 foreach (ModelValidationResult validationResult in ModelValidator.GetModelValidator(metadata, t).Validate(null))
37 {
38 ModelState.AddModelError(validationResult.MemberName, validationResult.Message);
39 errorMsgList.Add(validationResult.Message);
40 }
41 errorMsg = string.Join(",", errorMsgList);
42 return ModelState.IsValid;
43 }
44 }
至此整个AOP过滤器编码全部完成，在用户提交表单之前，API接口会首先进入CHKFormInput 过滤器验证参数合法性，如验证失败，将不进入提交订单的API接口
感谢您的阅读！
时间： 2024-11-08 08:14:53