编写自定义约束时,可以通过一个验证器实现验证多个注释。例如,我有几个注释规定了不同的@size注释,但我希望它们都指向同一个验证器类,它进行一些全局检查,即所有必须匹配某个正则表达式。据我所知,实现采用一种注释类型。
一个注释
@Target( { METHOD, FIELD, ANNOTATION_TYPE, TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = {UCNValidator.class})
@Documented
@Size(min = 9, max = 9, message = "{exactlength}")
public @interface UCN {
String message() default "{invalidFormat}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String fieldName() default "ucn";
}
验证器
public class UCNValidator implements ConstraintValidator<UCN, String>
{
private String pattern = "[a-zA-Z].*";
private String fieldName;
@Override
public void initialize( UCN constraintAnnotation )
{
this.fieldName = constraintAnnotation.fieldName();
}
@Override
public boolean isValid( String value, ConstraintValidatorContext constraintValidatorContext )
{
if ( value != null )
{
if ( !value.matches(pattern) )
{
//do some stuff
return false;
}
}
return true;
}