jsf custom converter example

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JSF Custom Converter Example:

Let us discuss how to create custom converter in JSF with example.

Steps to create custom converter in JSF:

1. First create a converter class by implementing javax.faces.convert.Converter interface
2. Override getAsObject() and getAsString() methods of above interface.
3. Assign a unique converter ID to the custom convertor by using @FacesConverter annotation.
4. Use custom converter class to JSF component via f:converter tag.

Example:

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 custom converter example.</title> 
	</h:head>
    <h:body> 
      <h3>JSF custom converter example.</h3>
      <h:form>
        <h:inputText id="urlId" value="#{test.urlDetail}" 
            label="Enter URL: " >
            <f:converter converterId=
                     "com.w3schools.business.URLConverter" />
         </h:inputText>	
         <br/><br/>	 
         <h:commandButton value="Submit" action="welcome"/>
         <h:message for="urlId" style="color:red" />
      </h:form>
    </h:body>
 
</html>

Test.java

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
 
/**
 * Managed bean.
 * @author w3schools
 */
@ManagedBean(name="test")
@SessionScoped
public class Test {
	private URLDetail urlDetail;
 
	public URLDetail getUrlDetail() {
		return urlDetail;
	}
 
	public void setUrlDetail(URLDetail urlDetail) {
		this.urlDetail = urlDetail;
	}
 
}

URLConverter.java

import java.net.URI;
import java.net.URISyntaxException;
 
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.ConverterException;
import javax.faces.convert.FacesConverter;
 
@FacesConverter("com.w3schools.business.URLConverter")
public class URLConverter implements Converter {
 
	@Override
	public Object getAsObject(FacesContext facesContext, 
			UIComponent component, String value) {
		StringBuilder url = new StringBuilder();
 
		if (!value.startsWith("http://", 0)) {
			url.append("http://");
		}
		url.append(value);
 
		try {
			new URI(url.toString());
		} catch (URISyntaxException e) {
			FacesMessage msg = 
				new FacesMessage("Error converting URL",
					"Invalid URL format");
			msg.setSeverity(FacesMessage.SEVERITY_ERROR);
			throw new ConverterException(msg);
		}
 
		URLDetail urlData = new URLDetail(url.toString());
		return urlData;
	}
 
	@Override
	public String getAsString(FacesContext facesContext, 
			UIComponent component, Object value) {
		return value.toString();
	}
 
}

URLDetail.java

public class URLDetail {
	private String url;
 
    public URLDetail(String url){
      this.url = url;
    }
 
    public String getUrl() {
	return url;
    }
 
    public void setUrl(String url) {
	this.url = url;
    }
 
    public String toString(){
      return url;
   }	
}

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 custom converter example.</title>
	</h:head>
    <h:body> 
      <h3>JSF custom converter example.</h3>
      <h:outputText label="URL: " 
                        value="#{test.urlDetail.url}" />
    </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">
 
</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-mapping>
        <servlet-name>faces</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
 
</web-app>

URL:

http://localhost:7001/JSFExample31/faces/test.xhtml

Output:

JSF example31-1
 
Enter any website name.
JSF example31-2
 
Click Submit button.
JSF example31-3
 
Download this example.