diff options
Diffstat (limited to 'sampleUses/src/main/java/CreditCardNumber.java')
-rw-r--r-- | sampleUses/src/main/java/CreditCardNumber.java | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/sampleUses/src/main/java/CreditCardNumber.java b/sampleUses/src/main/java/CreditCardNumber.java new file mode 100644 index 0000000..ef5f711 --- /dev/null +++ b/sampleUses/src/main/java/CreditCardNumber.java @@ -0,0 +1,27 @@ +import java.lang.annotation.Documented; +import java.lang.annotation.ElementType; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; + +import javax.annotation.MatchesPattern; +import javax.annotation.meta.TypeQualifier; +import javax.annotation.meta.TypeQualifierValidator; +import javax.annotation.meta.When; + +@Documented +@TypeQualifier +@MatchesPattern("[0-9]{16}") +@Retention(RetentionPolicy.RUNTIME) +public @interface CreditCardNumber { + class Checker implements TypeQualifierValidator<CreditCardNumber> { + + public When forConstantValue(CreditCardNumber annotation, Object v) { + if (!(v instanceof String)) + return When.NEVER; + String s = (String) v; + if (LuhnVerification.checkNumber(s)) + return When.ALWAYS; + return When.NEVER; + } + } +} |