package ajax;
import java.io.Serializable;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.validator.ValidatorException;
@ManagedBean(name="ajax")
@SessionScoped
public class UserBean implements Serializable {
private String name="";
private String password;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public void validateName(FacesContext fc,UIComponent c,Object value){
if(((String)value).contains("_")){
throw new ValidatorException(new FacesMessage("Name cannot contain underscores!"));
}
}
public void validatePassword(FacesContext fc,UIComponent c,Object value){
if(((String)value).length()<6){
throw new ValidatorException(new FacesMessage("Password at least six words!"));
}
}
}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<h:head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Insert title here</title>
</h:head>
<h:body>
<h:form>
<p>
<h:outputText value="Name"/>
<h:inputText id="name" value="#{ajax.name}" validator="#{ajax.validateName}">
<f:ajax event="blur" execute="@this" render="nameError"/>
</h:inputText>
<h:message for="name" id="nameError" style="color:red" /></p>
<h:outputText value="Password"/>
<h:inputSecret id="password" value="#{user.password}" validator="#{ajax.validatePassword}">
<f:ajax event="blur" render="passwordError"/>
</h:inputSecret>
<h:message for="password" id="passwordError" style="color:red" />
</h:form>
</h:body>
</html>
原文地址：http://blog.csdn.net/zhaoyayua/article/details/40375627
