JSF 2 validateLength example
“f:validateLength” is a JSF string length validator tag, which is used to check the length of a string. For example,
<h:inputText id="username" value="#{user.username}">
<f:validateLength minimum="5" maximum="10" />
</h:inputText>
When this form is submitted, the validator will make sure the “username” text field contains a minimum length of 5, maximum length of 10.
“f:validateLength” example
A JSF 2.0 example to show the use of “f:validateLength” tag to validate the length of a “username” text field, when the validator failed, display the error message via “h:message” tag.
1. Managed Bean
A dummy managed bean to hold the “username” property only.
package com.mkyong;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
@ManagedBean(name="user")
@SessionScoped
public class UserBean implements Serializable{
String username;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}
2. JSF Page
JSF XHTML page, show the use of “f:validateLength” tag to make sure the form’s input “username” contains a minimum length of 5, maximum length of 10.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.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"
xmlns:c="http://java.sun.com/jsp/jstl/core"
>
<h:body>
<h1>JSF 2 validateLength example</h1>
<h:form>
<h:panelGrid columns="3">
Enter UserName :
<h:inputText id="username" value="#{user.username}"
size="20" required="true"
label="UserName" >
<f:validateLength minimum="5" maximum="10" />
</h:inputText>
<h:message for="username" style="color:red" />
</h:panelGrid>
<h:commandButton value="Submit" action="result" />
</h:form>
</h:body>
</html>
3. Demo
Minimum length validation failed.
Maximum length validation failed.
Download Source Code
Download It – JSF-2-ValidateLength-Example.zip (9KB)
Reference
About Author
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how to restrict the unicode , suppose i am entering chineese/russian character in this field.
Greetings. The tag h: inputText can change the description of the output error using reguiredMesage. It is possible to change the description of any errors in the tag f: validateLengtn?
thank you