Apache Struts 2 Documentation > Home > Guides > Core Developers Guide > Annotations > Validation Annotation
#editReport()

This annotation has been deprecated since 2.1 as its previous purpose, to define classes that support annotation validations, is no longer necessary.

Usage

The Validation annotation must be applied at Type level.

Parameters

Parameter Required Default Notes
validations yes  

Examples

An Annotated Interface

  • Mark the interface with @Validation()
  • Apply standard or custom annoations at method level
@Validation()
public interface AnnotationDataAware {

    void setBarObj(Bar b);

    Bar getBarObj();

    @RequiredFieldValidator(message = "You must enter a value for data.")
    @RequiredStringValidator(message = "You must enter a value for data.")
    void setData(String data);

    String getData();
}

An Annotated Class

@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;
    }
}

When multiple methods are used to map different actions on the same class, and one of them is annotated with @Validations, those validators will be triggered for all the actions, unless they are annotated with @SkipValidation or validateAnnotatedMethodOnly is set to true in the "validation" interceptor, like:
<interceptor-ref name="validation">
    <param name="validateAnnotatedMethodOnly">true</param>
    <param name="excludeMethods">input,back,cancel,browse</param>
</interceptor-ref>