Manual validation on specific fields in Struts 2

For example I have an Action class called UsersAction where I have some methods like: login, logout, register, and so on.

And I have written validate() method as follows:

@Override
public void validate() {
    if ("".equals(username)) {
        addFieldError("username", getText("username.required"));
    }
    if ("".equals(email)) {
        addFieldError("email", getText("email.required"));
    } else if (!Utils.isValidEmail(email)) {
        addFieldError("email", getText("invalid.email.address"));
    }
    if ("".equals(phone)) {
        addFieldError("phone", getText("phone.required"));
    }
    if ("".equals(password)) {
        addFieldError("password", getText("password.required"));
    }
}

The problem is that this solution works only when register action is called.

Anyway, it wont work on login or logout, because it will check if the fields aren't null or email is correct, and always will give an error.

Okay, the solution for logout was to add @SkipValidation annotation above it, but I don't know how to tell to it that login have only 2 fields username and password, and it's not necessary to check email and phone too. I don't want to write an Action class for each action in part, because the purpose of Struts 2 is not this.

Create validateMethodName methods, where methodName is the name of the method, e.g.,

validateLogin() { ... }

Otherwise provide some form of contextual information to your validate method.