JSF Tutorial - JSF Messages Tag

The h:messages tag shows all the messages at one place corresponding to UI elements.

The following JSF tag

<h:messages style="color:red;margin:8px;" />

If username entered is more than 20 characters and password entered is less than 5 characters.

<ul style="color:red;margin:8px;">
   <li>  UserName: Validation Error: 
   Length is greater than allowable maximum of '20' </li>
   <li>  Password: Validation Error: 
   Length is less than allowable minimum of '5' </li>
</ul>

Tag Attributes

Attribute	Description
id	id for the tag
binding	Reference to the component used in a backing bean
rendered	A boolean value; false would suppress rendering
styleClass	Cascading stylesheet (CSS) class name
for	The component ID whose message is displayed
errorClass	CSS class applied to error messages
errorStyle	CSS style applied to error messages
fatalClass	CSS class applied to fatal messages
fatalStyle	CSS style applied to fatal messages
globalOnly	Instruction to display only global messages. Default: false
infoClass	CSS class applied to information messages
infoStyle	CSS style applied to information messages
layout	Specification for message layout: table or list
showDetail	A boolean that determines whether message details are shown. Defaults are false for h:messages, true for h:message
showSummary	A boolean that determines whether message summaries are shown. Defaults are true for h:messages, false for h:message
tooltip	A boolean to set whether message details are rendered in a tooltip; the tooltip is only rendered if showDetail and showSummary are true
warnClass	CSS class for warning messages
warnStyle	CSS style for warning messages
style	Inline style information
title	A title used for accessibility. Browsers typically create tooltips for the title's value

Example

The following code is from demo.xhtml.

<?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:ui="http://java.sun.com/jsf/facelets"
      >
     
    <h:body>
    <h:form>
      <h:messages style="color:red;margin:8px;" />
      <br />
      <h:panelGrid columns="3">
        Enter your 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" />

        Enter your age :
        <h:inputText id="age" value="#{user.age}" 
          size="20" required="true"
          label="Age" >
          <f:validateLongRange for="age" minimum="1" maximum="200" />
        </h:inputText>
 
        <h:message for="age" style="color:red" />
        
      </h:panelGrid>
    
      <h:commandButton value="Submit" action="result" />
    
    </h:form>
    
    </h:body>
</html>

The following code is from UserBean.java.

package com.java2s.common;


import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
 
@ManagedBean(name="user")
@SessionScoped
public class UserBean implements Serializable{
  
  private static final long serialVersionUID = 1L;
  
  public String username;
  public int age;
  
  public String getUsername() {
    return username;
  }
  public void setUsername(String username) {
    this.username = username;
  }
  public int getAge() {
    return age;
  }
  public void setAge(int age) {
    this.age = age;
  }
  
}

The following code is from result.xhtml.

<?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"
      >
     
    <h:body>
    
    Username : #{user.username}
    
    <br />
    
    Age : #{user.age}
    
    </h:body>
</html>

Download Message_Tag.zip

To RUN

Copy the generated WAR file from the target folder to Tomcat deployment folder and run Tomcat-Install-folder/bin/startup.bat.

After Tomcat finish starting, type the following URL in the browser address bar.

http://localhost:8080/simple-webapp/demo.xhtml