Can you change an annotation message at run time?
I'm trying to include a dynamic message in my annotation that changes the main body of the text based on the values that are found in the other variables that are passed to it. I set a default message, but when a certain indicator is set, I want to display a different message. Is this possible?
Here's my annotation -
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch
{
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String first();
String second();
String third() default "";
String match() default "true";
String message() default "{error.theseValuesDontMatch}";
/**
* Defines several <code>@FieldMatch</code> annotations on the same element
*
* @see FieldMatch
*/
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Documented @interface List
{
FieldMatch[] value();
}
}
Here's the validator class used by the annotation -
public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object>
{
private String firstFieldName;
private String secondFieldName;
private String thirdFieldName;
private String match;
private String message;
@Override
public void initialize(FieldMatch constraintAnnotation)
{
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
thirdFieldName = constraintAnnotation.third();
match = constraintAnnotation.match();
if(match != null && !Boolean.getBoolean(match)){
message = "error.theseValuesMustNotMatch";
}
}
@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context)
{
try
{
final Object firstObj = BeanUtils.getProperty(value, firstFieldName);
final Object secondObj = BeanUtils.getProperty(value, secondFieldName);
final Object thirdObj = BeanUtils.getProperty(value, thirdFieldName);
final String same = BeanUtils.getProperty(value, match);
boolean valid = false;
if(same != null && Boolean.getBoolean(same)){
if("".equals(thirdObj)){
valid = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj) ;
}
else{
valid = firstObj != null && firstObj.equals(secondObj) && firstObj.equals(thirdObj) ;
}
}
else{
if("".equals(thirdObj)){
valid = firstObj == null && secondObj == null || firstObj != null && !firstObj.equals(secondObj) ;
}
else{
valid = firstObj != null && !(firstObj.equals(secondObj) && firstObj.equals(thirdObj)) ;
}
}
return valid ;
}
catch (final Exception ignore)
{
// ignore
}
return true;
}
}
The piece I'm most interested开发者_Python百科 in is the code that reads -
if(match != null && !Boolean.getBoolean(match)){
message = "password.error.theseValuesMustNotMatch";
}
Here's how I was able to do this -
@Override
public void initialize(FieldMatch constraintAnnotation)
{
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
thirdFieldName = constraintAnnotation.third();
match = constraintAnnotation.match();
//set a message variable on initialization
if("true".equals(match)){
message = constraintAnnotation.message();
}
else{
message = "{password.error.threeQuestionsSameAnswer}";}
}
@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context)
{
Object firstObj = null;
Object secondObj = null;
Object thirdObj = null;
//disable existing violation message
context.disableDefaultConstraintViolation();
//build new violation message and add it
context.buildConstraintViolationWithTemplate(message).addConstraintViolation();
etc.........
}
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