Custom validator

Before writing code, learn about a new annotation@Validator. Its function is to declare a class as a validator, and its parameters need to be bound to the annotations corresponding to the custom validator. This The role of annotations is the same as @VRequried and other annotations. Developers can configure verification rules through this annotation;

In this example, we create a simple custom validator to Verify whether the email address entered by the current user already exists;

• Create a custom validator annotation:

  @Target({ElementType.FIELD, ElementType.PARAMETER})
  @Retention(RetentionPolicy.RUNTIME)
  @Documented
  public @interface VEmailCanUse {
  
      /**
       * @return 自定义验证消息
       */
      String msg() default "";
  }

• Implement the IValidator interface and declare the @Validator annotation:

  @Validator(VEmailCanUse.class)
  public class EmailCanUseValidator implements IValidator {
  
      public ValidateResult validate(ValidateContext context) {
          ValidateResult _result = null;
          if (context.getParamValue() != null) {
              // 假定邮箱地址已存在
              VEmailCanUse _anno = (VEmailCanUse) context.getAnnotation();
              _result = new ValidateResult(context.getParamName(), StringUtils.defaultIfBlank(_anno.msg(), "邮箱地址已存在"));
          }
          return _result;
      }
  }

• Test code:

  public class VEmailCanUseBean {
  
      @VRequried
      @VEmail
      @VEmailCanUse
      private String email;
  
      //
      // 此处省略了Get/Set方法
      //
  }
  
  public static void main(String[] args) throws Exception {
      YMP.get().init();
      try {
          Map<String, Object> _params = new HashMap<String, Object>();
          _params.put("ext.email", "demo@163.com");
  
          Map<String, ValidateResult> _results = Validations.get().validate(VEmailCanUseBean.class, _params);
          //
          for (Map.Entry<String, ValidateResult> _entry : _results.entrySet()) {
              System.out.println(_entry.getKey() + " : " + _entry.getValue().getMsg());
          }
      } finally {
          YMP.get().destroy();
      }
  }

• Execution result:

  ext.email : 邮箱地址已存在