Jsf param html tag

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JSF f:param tag is used to pass parameters to JSF UI Component.
Note:
1. If f:param component is used with h:outputFormat then it specifies the placeholder.
2. If f:param component is used with other component then it specifies the request parameter.

Attributes of f:param tag.

Attribute Description
id Identifier for a component
binding Reference to the component that can be used in a backing bean
name An optional name for parameter component
value The value stored in component

Example:

Test.java

import java.util.Map;
 
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;
 
/**
 * Managed bean.
 * @author w3schools
 */
@ManagedBean(name="test")
@SessionScoped
public class Test {
	private String userName;	
 
	public String getUserName() {
		return userName;
	}
 
	public void setUserName(String userName) {
		this.userName = userName;
	}
 
	public String displayParam() {
		FacesContext fc = FacesContext.getCurrentInstance();
	    Map<String,String> params = 
	    fc.getExternalContext().getRequestParameterMap();
	    userName =  params.get("userName");  
		return "success";
	}
}

test.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:head>
		<title>JSF param example.</title> 
	</h:head>
    <h:body> 
      <h3>JSF param example.</h3>
      <h:form>
	     <h:outputFormat value="Hello {0}.">
	        <f:param value="World" />
	     </h:outputFormat>
	     <br/><br/>
         <h:commandButton id="submit" 
            value="Display Param" action="#{test.displayParam}">
            <f:param name="userName" value="Jai" />
      	 </h:commandButton>
      </h:form>
    </h:body>
 
</html>

welcome.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:head>
		<title>JSF param example.</title>
	</h:head>
    <h:body> 
      <h3>#{test.userName}</h3>
    </h:body>
 
</html>

faces-config.xml

<?xml version="1.0" encoding="windows-1252"?>
<faces-config version="2.0" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xi="http://www.w3.org/2001/XInclude" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd">
 
<navigation-rule>
   <from-view-id>test.xhtml</from-view-id>
   <navigation-case>
      <from-outcome>success</from-outcome>
      <to-view-id>welcome.xhtml</to-view-id>
   </navigation-case>   
</navigation-rule>
 
</faces-config>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 
    	xmlns="http://java.sun.com/xml/ns/javaee" 
    	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
 
    <servlet>
        <servlet-name>faces</servlet-name>
        <servlet-class>
          javax.faces.webapp.FacesServlet
        </servlet-class>
    </servlet>
 
	<servlet-mapping>
        <servlet-name>faces</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
 
</web-app>

URL:

http://localhost:7001/JSFExample22/faces/test.xhtml

Output:

JSF example22-1
Click on Display Param button.
JSF example22-2
 
Download this example.