<!DOCTYPE validators PUBLIC 
         "-//OpenSymphony Group//XWork Validator 1.0.2//EN" 
         "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
 <validators>
   <!-- Field Validators for email field -->
   <field name="email">
       <field-validator type="required" short-circuit="true">
           <message>You must enter a value for email.</message>
       </field-validator>
       <field-validator type="email" short-circuit="true">
           <message>Not a valid e-mail.</message>
       </field-validator>
   </field>
   <!-- Field Validators for email2 field -->
   <field name="email2">
      <field-validator type="required">
           <message>You must enter a value for email2.</message>
       </field-validator>
      <field-validator type="email">
           <message>Not a valid e-mail2.</message>
       </field-validator>
   </field>
   <!-- Plain Validator 1 -->
   <validator type="expression">
       <param name="expression">email.equals(email2)</param>
       <message>Email not the same as email2</message>
   </validator>
   <!-- Plain Validator 2 -->
   <validator type="expression" short-circuit="true">
       <param name="expression">email.startsWith('mark')</param>
       <message>Email does not start with mark</message>
   </validator>
 </validators>
 

 
 @Validation()
 public class SimpleAnnotationAction extends ActionSupport {
 
     @RequiredFieldValidator(type = ValidatorType.FIELD, message = "You must enter a value for bar.")
     @IntRangeFieldValidator(type = ValidatorType.FIELD, min = "6", 
      max = "10", message = "bar must be between ${min} and ${max}, current value is ${bar}.")
     public void setBar(int bar) {
         this.bar = bar;
     }
 
     public int getBar() {
         return bar;
     }
 
     @Validations(
             requiredFields =
                     {@RequiredFieldValidator(type = ValidatorType.SIMPLE, 
 fieldName = "customfield", message = "You must enter a value for field.")},
             requiredStrings =
                     {@RequiredStringValidator(type = ValidatorType.SIMPLE,
  fieldName = "stringisrequired", message = "You must enter a value for string.")},
             emails =
                     { @EmailValidator(type = ValidatorType.SIMPLE, 
 fieldName = "emailaddress", message = "You must enter a value for email.")},
             urls =
                     { @UrlValidator(type = ValidatorType.SIMPLE, 
 fieldName = "hreflocation", message = "You must enter a value for email.")},
             stringLengthFields =
                     {@StringLengthFieldValidator(type = ValidatorType.SIMPLE, trim = true, minLength="10" , 
 maxLength = "12", fieldName = "needstringlength", message = "You must enter a stringlength.")},
             intRangeFields =
                     { @IntRangeFieldValidator(type = ValidatorType.SIMPLE, 
 fieldName = "intfield", min = "6", max = "10", message = "bar must be between ${min} and ${max}, current value is ${bar}.")},
             dateRangeFields =
                     {@DateRangeFieldValidator(type = ValidatorType.SIMPLE, 
 fieldName = "datefield", min = "-1", max = "99", message = "bar must be between ${min} and ${max}, current value is ${bar}.")},
             expressions = {
                 @ExpressionValidator(expression = "foo > 1", 
 message = "Foo must be greater than Bar 1. Foo = ${foo}, Bar = ${bar}."),
                 @ExpressionValidator(expression = "foo > 2", 
 message = "Foo must be greater than Bar 2. Foo = ${foo}, Bar = ${bar}."),
                 @ExpressionValidator(expression = "foo > 3", 
 message = "Foo must be greater than Bar 3. Foo = ${foo}, Bar = ${bar}."),
                 @ExpressionValidator(expression = "foo > 4",
  message = "Foo must be greater than Bar 4. Foo = ${foo}, Bar = ${bar}."),
                 @ExpressionValidator(expression = "foo > 5",
  message = "Foo must be greater than Bar 5. Foo = ${foo}, Bar = ${bar}.")
     }
     )
     public String execute() throws Exception {
         return SUCCESS;
     }
 }
 

 
 public class HelloWorldValidator extends ValidationFilter {
 
     private static final String FIELD_REQUIRED_ERROR = "Field required!";
     private static final String INVALID_USERNAME_LENGTH = "Username length invalid!";
     private static final String INVALID_AGE = "Invalid age!";
     private static final String INVALID_PASSWORD_LENGTH = "Invalide password length!";
     private static final String PASSWORD_DOES_NOT_MATCH = "Passwords do not match!";
 
     public void initValidator() {
         
         add("username", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
         add("username", new StringRule(6, 30), INVALID_USERNAME_LENGTH);
         
         add("age", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
         add("age", new IntegerRule(18, 50), INVALID_AGE);
         
         add("password", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
         add("password", new StringRule(4, 20), INVALID_PASSWORD_LENGTH);
         add("password", new EqualRule("password", "passconf"), PASSWORD_DOES_NOT_MATCH);
         
         add("passconf", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
     }
 
 }
 

 
 ###############################################
 # Messages for the filter HelloWorldValidator #
 ###############################################
  
 required = Required field cannot be left blank
 2 = Your username must be between %min% and %max% characters long.
 3 = You must be %min% years old or older.
 4 = Your password must be between %min% and %max% characters long.
 5 = Passwords do not match.
 
 

 public class HelloWorldValidator extends ValidationFilter {
 
     private static final String FIELD_REQUIRED_ERROR = "required"; // to illustrate that this can be a string too
     private static final int INVALID_USERNAME_LENGTH = 2;
     private static final int INVALID_AGE = 3;
     private static final int INVALID_PASSWORD_LENGTH = 4;
     private static final int PASSWORD_DOES_NOT_MATCH = 5;
 
     public void initValidator() {
         
         add("username", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
         add("username", new StringRule(6, 30), INVALID_USERNAME_LENGTH);
         
         add("age", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
         add("age", new IntegerRule(18, 50), INVALID_AGE);
         
         add("password", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
         add("password", new StringRule(4, 20), INVALID_PASSWORD_LENGTH);
         add("password", new EqualRule("password", "passconf"), PASSWORD_DOES_NOT_MATCH);
         
         add("passconf", new RequiredFieldRule(), FIELD_REQUIRED_ERROR);
     }
 
 }
 

 /**
  * Observação bem grande na documentação, para te ajudar: 
  *  
  *  To allow Struts to recognize that a conversion error has occurred,
  *   the converter class need to throw XWorkException or preferably 
  * TypeConversionException.
 */
 public class MyConverter extends StrutsTypeConverter {
 
     public Object convertFromString(Map context, String[] values, Class toClass) {
        .....
     }
 
     public String convertToString(Map context, Object o) {
        .....
     }
  }
 

 
 public class MyConverter extends BasicConverter {
 	
 	public Object convert(Object value) throws ConversionException {
         
                // ...       
         }
 }
 
 // ou ainda para converter baseado no locale
 
 public class MyConverter extends LocaleConverter {
 	
 	public Object convert(Object value, Locale loc) throws ConversionException {
         
                // ...       
         }
 }
 

 import com.opensymphony.xwork2.ActionInvocation;
 import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
 
 public class SimpleInterceptor extends AbstractInterceptor {
 
     public String intercept(ActionInvocation invocation) throws Exception {
        MyAction action = (MyAction)invocation.getAction();
        action.setDate(new Date());
        return invocation.invoke();
     }
 }
 

 public class SimpleFilter implements Filter {
 
     public String filter(InvocationChain chain) throws Exception {
        Action action = chain.getAction();
        Input input = action.getInput();
 
        input.setValue("someDate", new Date());
 
        return chain.invoke();
     }
 
     public void destroy() { }
 }