1package javax.annotation; 2 3import java.lang.annotation.Documented; 4import java.lang.annotation.Retention; 5import java.lang.annotation.RetentionPolicy; 6import java.util.regex.Pattern; 7import java.util.regex.PatternSyntaxException; 8 9import javax.annotation.meta.TypeQualifierNickname; 10import javax.annotation.meta.TypeQualifierValidator; 11import javax.annotation.meta.When; 12 13/** 14 * This qualifier is used to denote String values that should be a Regular 15 * expression. 16 * 17 */ 18@Documented 19@Syntax("RegEx") 20@TypeQualifierNickname 21@Retention(RetentionPolicy.RUNTIME) 22public @interface RegEx { 23 When when() default When.ALWAYS; 24 25 static class Checker implements TypeQualifierValidator<RegEx> { 26 27 public When forConstantValue(RegEx annotation, Object value) { 28 if (!(value instanceof String)) 29 return When.NEVER; 30 31 try { 32 Pattern.compile((String) value); 33 } catch (PatternSyntaxException e) { 34 return When.NEVER; 35 } 36 return When.ALWAYS; 37 38 } 39 40 } 41 42} 43