（轉）
下面是一個email驗證器的示例: ?
EmailValidator.java:
import?javax.faces.application.FacesMessage;
import?javax.faces.component.UIComponent;
import?javax.faces.context.FacesContext;
import?javax.faces.validator.Validator;
import?javax.faces.validator.ValidatorException;
?
public?class?EmailValidator?implements?Validator?{
?
????private?String?errorMessage?=?null;
?
????public?void?setErrorMessage(String?errorMessage)?{?this.errorMessage?=?errorMessage;?}
?
????public?void?validate(FacesContext?context,?UIComponent?component,?Object?value)?{
????????if?(null?==?value)?{
????????????return;
????????}
?
????????String?email?=?(String)?value;
?
????????if?(-1?==?email.indexOf('@',?1)?||?-1?==?email.indexOf('.'))?{
????????????if?(errorMessage?!=?null)?{
????????????????throw?new?ValidatorException(new?FacesMessage(Tags.eval(errorMessage)));
????????????}?else?{
????????????????//?use?default?validator?message
????????????????throw?new?ValidatorException(null);
????????????}
????????}
????}
}
|
Tags.java:
import?javax.faces.application.Application;
import?javax.faces.component.UIComponent;
import?javax.faces.component.UIInput;
import?javax.faces.context.FacesContext;
import?javax.faces.el.MethodBinding;
import?javax.faces.el.ValueBinding;
import?javax.faces.event.ValueChangeEvent;
import?javax.faces.webapp.ConverterTag;
import?javax.faces.webapp.UIComponentTag;
?
public?class?Tags?{
???//?Converter?Tags?and?Validator?Tags?helper?methods
????public?static?String?eval(String?expression)?{
????????if?(expression?!=?null?&&?UIComponentTag.isValueReference(expression))?{
????????????FacesContext?context?=?FacesContext.getCurrentInstance();
????????????Application?app?=?context.getApplication();
????????????ValueBinding?vb?=?app.createValueBinding(expression);
????????????return?""?+?vb.getValue(context);
????????}?else?{
????????????return?expression;
????????}
????}
} |
?
?
?
EmailValidatorTag.java:
import?javax.faces.component.UIComponent;
import?javax.faces.validator.Validator;
import?javax.faces.webapp.ValidatorTag;
import?javax.servlet.jsp.JspException;
?
public?class?EmailValidatorTag?extends?ValidatorTag?{
?
????private?String?errorMessage?=?null;
?
????public?EmailValidatorTag()?{
????????setValidatorId("Email");
????}
?
????public?void?setErrorMessage(String?errorMessage)?{?this.errorMessage?=?errorMessage;?}
?
????public?Validator?createValidator()?throws?JspException?{
????????EmailValidator?validator?=?(EmailValidator)?super.createValidator();
????????validator.setErrorMessage(errorMessage);
?
????????return?validator;
????}
?
????public?void?release()?{
????????errorMessage?=?null;
????}
} |
?
?
faces-config.xml:
<validator>
<validator-id>Email</validator-id>
<validator-class>EmailValidator</validator-class>
</validator>
mytags.tld:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE taglib PUBLIC
"-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
"http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>1.2</jspversion>
<shortname>mytags</shortname>
<uri>mytags</uri>
<tag>
<name>validateEmail</name>
<tagclass>EmailValidatorTag</tagclass>
<attribute>
<name>errorMessage</name>
<description>message if a validation error occurs</description>
</attribute>
</tag>
</taglib>
?
mypage.jsp:
<h:inputText id="email" required="true">
<mytags:validateEmail errorMessage="#{bean.message}"/>
</h:inputText>