How to use custom annotations to verify restful request parameters

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Custom annotations for verification of restful request parameters

When developing with springmvc, we usually add annotations such as @ NotNull () to the method parameter entity class in controller, and then add

@ Vilad annotation, so that when there is a request, it will automatically check whether the parameter is legal according to our annotation, avoiding our manual verification.

However, sometimes the self-contained verification annotations can not meet our business verification needs, so it is necessary for us to customize the verification annotations and customize us according to the business requirements.

Your own verification notes.

Let's look at an example:

1. First, we use @ interface to define an annotation @ Target ({METHOD, FIELD, ANNOTATION_TYPE}) @ Retention (RUNTIME) @ Constraint (validatedBy = ByteLengthValidator.class) / / specify the annotation verification implementation class using @ Constraint. This is a restricted annotation and can only use the specified implementation class @ Documentedpublic @ interface ByteLength {int min () default 0; int max () default 2147483647; String charsetName () default "GBK". String message () default "can only be between {min} and {max}"; Class [] groups () default {}; Class