Converter Application
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Tag description: JSF <f:converter> Tag is register a Converter instance on UIcomponent associate with the enclosing parent tag.
Interface Converter, describing a Java class that can perform String-to-Object or Object-to-String conversions between model data objects and a String representation of those objects that is suitable for rendering.
Code
<f:converter>
Example :
Step 1: Welcome page of Example
<%--
Name= welcomeJSF
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib prefix="f" uri="http://java.sun.com/jsf/core"%>
<%@taglib prefix="h" uri="http://java.sun.com/jsf/html"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%--
This file is an entry point for JavaServer Faces application.
--%>
<f:view>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>r4r.co.in</title>
</head>
<body>
<h1><h:outputText value="Tag <f:converter> Example"/></h1>
<h:form id="converter">
<%--Display Error message --%>
<h:messages for="converter:name" globalOnly="true" style="color:red" />
<h:panelGrid columns="2" cellpadding="2" cellspacing="2" >
<h:outputLabel value="Website name" />
<h:inputText id="name" value="#{converter.name}" required="true" size="30">
<f:converter converterId="ConverterClass" />
</h:inputText>
<h:commandButton action="#{converter.submit()}" value="Submit" />
</h:panelGrid>
<br><br>
<%-- Display result --%>
<h:panelGrid rendered="#{converter.flag != false}" >
Website url: <h:outputText value="#{converter.name}"/>
</h:panelGrid>
</h:form>
</body>
</html>
</f:view>
Step 2: Faces-config.xml file for mapping resource
<?xml version='1.0' encoding='UTF-8'?> <!-- =========== FULL CONFIGURATION FILE ========= --> <faces-config version="2.0" 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-facesconfig_2_0.xsd"> <managed-bean> <managed-bean-name>converterBean</managed-bean-name> <managed-bean-class>r4r.JSF2.converterBean</managed-bean-class> <managed-bean-scope>request</managed-bean-scope> </managed-bean> <!-- == Add Converter class invoked by converterId in JSP == --> <converter> <converter-id>ConverterClass</converter-id> <converter-class>r4r.JSF2.ConverterClass</converter-class> </converter> </faces-config>
Step 3: ManagedBean class for provide logic in program
/*
* Save as a converterBean.java
*/
package r4r.JSF2;
import javax.faces.bean.ManagedBean;
/* --Bean name -- */
@ManagedBean(name = "converter")
public class converterBean {
private String name;
private boolean flag = false;
/* -- Getter/Setter -- */
public boolean isFlag() {
return flag;
}
public void setFlag(boolean flag) {
this.flag = flag;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
/* -- submit method -- */
public String submit() {
flag = true;
return "submit";
}
}
Step 4: Converter class
/*
* Save as a ConverterClass.java
* Class is implements Converter interface that can perform
* Object-to-String and String-to-Object conversions
*/
package r4r.JSF2;
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.FacesConverter;
import org.hibernate.validator.constraints.impl.URLValidator;
@FacesConverter
public class ConverterClass implements Converter {
@Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
/* -- define string -- */
String HTTP = "http://www.";
String COM = ".com";
StringBuilder url = new StringBuilder();
/* -- Check input String start with http in front, if not then add it -- */
if (!value.startsWith(HTTP, 0)) {
url.append(HTTP);
}
/* -- Check input String contain .com in last, if not then add it -- */
if (value.indexOf(".com") == -1) {
url.append(value).append(COM);
}
//use common URL validator to validate URL
URLValidator uRLValidator = new URLValidator();
/*-- Check the URL validation --*/
if (uRLValidator.isValid(url.toString(), null)) {
FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_ERROR,
"URL conversion error!", "enter URL format is invalid");
context.addMessage(null, message);
}
/* -- Create a new NewURL url class which extends object-- */
NewURL newURL = new NewURL(url.toString());
return newURL;
}
@Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return value.toString();
}
}
step 5: NewURL class
/*
* Save as a NewURL.java
* Class in used to set/get the NewURL property .
*/
package r4r.JSF2;
public class NewURL {
private String NewFullURL;
NewURL(String NewFullURL) {
this.NewFullURL = NewFullURL;
}
/* -- Getter/Setter -- */
public String getNewFullURL() {
return NewFullURL;
}
public void setNewFullURL(String NewFullURL) {
this.NewFullURL = NewFullURL;
}
@Override
public String toString() {
return NewFullURL.toString();
}
}
Output:
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