Struts2 Validation

Validasi di struts2 ternyata cukup mudah ya :D. baru ngerti enaknya pake struts :). ada dua jenis tipe validasi di struts 2. cara pertama yaitu pake XML dan kedua pake annotation.

Untuk validasi Struts2 memakai XML cukup membuat XML dengan nama yang sama dengan java class yang akan di validasi di tambahkan dengan "-validation". misalnya jika nama java class nya "Login" maka nama XML validasi nya "Login-validation.xml". terus tinggal kita isi XML validasinya sesuai dengan field atau properties dari java class nya. misalnya seperti ini. kita punya sebuah class namanya Login dg field/propeties username dan password dg masing2 bertipe String. maka XML validasinya akan seperti ini..

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC 
"-//OpenSymphony Group//XWork Validator 1.0.2//EN" 
"http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

<validators>
    <field name="username">
        <field-validator type="requiredstring">
            <message>Username is required</message>
        </field-validator>
    </field>
    <field name="password">
        <field-validator type="requiredstring">
            <message>Password is required</message>
        </field-validator>
    </field>
</validators>

Seharusnya begini saja sudah cukup :). nanti saat user nginputkan nilai null atau gak ada isinya. akan muncul pesan error :).

Untuk Validasi Struts 2 pake Annotation Lihat aja ini :)

Annotation	Description
ConversionErrorFieldValidator Annotation	Checks if there are any conversion errors for a field.
DateRangeFieldValidator Annotation	Checks that a date field has a value within a specified range.
DoubleRangeFieldValidator Annotation	Checks that a double field has a value within a specified range.
EmailValidator Annotation	Checks that a field is a valid e-mail address.
ExpressionValidator Annotation	Validates an expression.
FieldExpressionValidator Annotation	Uses an OGNL expression to perform its validator.
IntRangeFieldValidator Annotation	Checks that a numeric field has a value within a specified range.
RegexFieldValidator Annotation	Validates a regular expression for a field.
RequiredFieldValidator Annotation	Checks that a field is non-null.
RequiredStringValidator Annotation	Checks that a String field is not empty.
StringLengthFieldValidator Annotation	Checks that a String field is of the right length.
StringRegexValidator Annotation	Invokes a regular expression to validate a String field.
UrlValidator Annotation	Checks that a field is a valid URL.
Validation Annotation	Marker annotation for validation at Type level.
Validations Annotation	Used to group validation annotations.
VisitorFieldValidator Annotation	Invokes the validation for a property's object type.
CustomValidator Annotation	Use this annotation for your custom validator types.

Source : http://struts.apache.org/2.0.11.2/docs/annotations.html