Custom validator error messages with Struts 2 xml validation

Question

I am running into a wall on how to create custom error messages in struts 2.

I iterate through a list of email addresses and validate using a custom validator. That validator will return true if any email addresses within the list are invalid.

Here is my custom validator:

public class EmailListValidator extends FieldValidatorSupport {
    @Override
    public void validate(Object obj) throws ValidationException {
        String fieldName = getFieldName();
        String fieldValue = (String) getFieldValue(fieldName, obj);
        if (fieldValue == null) return;
        fieldValue = fieldValue.trim();
        //
        if (errorCheck(fieldValue).length() > 1) {
            addFieldError(fieldName, obj);
        }       
    }

    private String errorCheck(String permList) {

        if (permList.equals("")) {
            return "";
        }

        String emailList = permList.toLowerCase();
        String []emails = emailList.split(";");

        emailList = "";

        for (int i=0; i<emails.length; i++) {
            if (emails[i].matches(EMAIL_PATTERN_STRING)) {
                //Do Nothing (Email is valid - or at least appears as such)
            } else {
                emailList += emails[i] + "; ";
            }
        }

        return emailList;
    }
}

As stated, in this case there either is an error or there isn't; if there is an error, it displays a very general error message.

<field name="reqEmail">

    <field-validator type="emaillist">
        <message key="validation.reqEmail.valid" />
    </field-validator>

</field>

How do I make it so the error message will state which exact email addresses were invalid?

How do I do so while still being able to refer to the message key, so the application can remain multilingual?

Answer 1

Create field (e.g. invalidEmails) with getter and setter in your EmailListValidator and assign invalid emails to it. In validation xml file you can access this property by using ${...} notation.

<field name="reqEmail">
  <field-validator type="emaillist">
    <message>${getText("validation.reqEmail.valid")}: ${invalidEmails}</message>
  </field-validator>
</field>