Use custom parameter annotation to verify exception error

Table of contents

1. Valid dependency introduction:

2. Examples show:

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1. Valid dependency introduction:

 2. Examples show:

In the Zoyi code, I can find that there are many custom parameter annotations, and many of them are used to check whether a parameter is abnormal or not. We can try to give an example:

If the Xss in the code is a custom annotation module:

Xss: Responsible for setting scope and built-in properties.

@Retention(RetentionPolicy.RUNTIME)
@Target(value = { ElementType.METHOD, ElementType.FIELD, ElementType.CONSTRUCTOR, ElementType.PARAMETER })
@Constraint(validatedBy = { XssValidator.class })
public @interface Xss
{
    String message()

    default "不允许任何脚本运行";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};
}

XssValidator: Write the verification rule XssValidator class.

public class XssValidator implements ConstraintValidator<Xss, String>
{
    private static final String HTML_PATTERN = "<(\\S*?)[^>]*>.*?|<.*? />";

    @Override
    public boolean isValid(String value, ConstraintValidatorContext constraintValidatorContext)
    {
        if (StringUtils.isBlank(value))
        {
            return true;
        }
        return !containsHtml(value);
    }

    public static boolean containsHtml(String value)
    {
        Pattern pattern = Pattern.compile(HTML_PATTERN);
        Matcher matcher = pattern.matcher(value);
        return matcher.matches();
    }
}

Example display: use this annotation in the responsible entity class in the entity of the domain layer.

@Xss(message = "User nickname cannot contain script characters")