Using Visitor Field Validator
Description
The followings show a simple example using Webwork’s Field Validators
Step 1
Create the jsp page.
<s:fielderror cssClass="alert alert-error"/>
<s:form method="POST" action="submitVisitorValidatorsExamples" namespace="/validation">
    <s:textfield name="user.name" label="User Name"/>
    <s:textfield name="user.age" label="User Age"/>
    <s:textfield name="user.birthday" label="Birthday"/>
    <s:submit label="Submit" cssClass="btn btn-primary"/>
</s:form>
Step 2
Create the action class.
public class VisitorValidatorsExampleAction extends AbstractValidationActionSupport {
    private User user;
    @StrutsParameter(depth = 1)
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
}
Step 3
Create the validator.xml.
<validators>
    <field name="user">
        <field-validator type="visitor">
            <param name="context">userContext</param>
            <param name="appendPrefix">true</param>
            <message>User:</message>
        </field-validator>
    </field>
</validators>
