In this example we
will see how to do custom validation in struts. To perform custom validation we
extend the UserForm from org.apache.struts.validator.ValidatorForm. The
UserForm contains two fields one for the phone number and the other for the
mobile number. Lets take the senario where either phone number or mobile number
is mandatory. If the validation takes into account only one field at a time
then Struts Validation Framework does an excellent job. What if we need to
consider more than one form field to validate data. In this case we go for
custom validation.
The UserForm class
contains the following code.
01.public class UserForm extends org.apache.struts.validator.ValidatorForm {
02.
03.private String phoneNumber;
04.private String mobileNumber;
05.
06.public String getPhoneNumber() {
07.return phoneNumber;
08.}
09.
10.public void setPhoneNumber(String
phoneNumber) {
11.this.phoneNumber = phoneNumber;
12.}
13.
14.public String getMobileNumber() {
15.return mobileNumber;
16.}
17.
18.public void setMobileNumber(String
mobileNumber) {
19.this.mobileNumber = mobileNumber;
20.}
21.
22.public UserForm() {
23.super();
24.}
25.
26.public ActionErrors validate(ActionMapping mapping, HttpServletRequest
request) {
27.ActionErrors errors = super.validate(mapping, request);
28.if ((getPhoneNumber() == null ||
getPhoneNumber().length() < 1) &&
29.(getMobileNumber() == null || getMobileNumber().length() < 1)) {
30.errors.add("phoneNumber", newActionMessage("error.phoneNumber.required"));
31.}
32.return errors;
33.}
34.}
We will override
the validate method in the UserForm to perform custom validation. First we call
the super class validate method inorder to save any errors returned by the
ValidatorForm. Then we check whether the mobile number or phone number is
present. If both are not present then we create a new ActionError and add the
errors to it. After performing all the validations we will save the errors if
any and return the ActionError object. If any errors are present the user will
be forwarded to the input page ( in our case it's the user.jsp page).
The following
message should be configured in the ApplicationResource.properties file. If
either phone number or mobile number is not entered by the user then the
following error message will be displayed.
1.error.phoneNumber.required = Either Phone number of
Mobile number is required.
On runing this
sample custom validation example the following page is displayed. The user
needs to enter either phone number or mobile number to enter successfully.
