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- JSF Tutorial
- JSF - Home
- JSF - Overview
- JSF - Environment Setup
- JSF - Architecture
- JSF - Life Cycle
- JSF - First Application
- JSF - Managed Beans
- JSF - Page Navigation
- JSF - Basic Tags
- JSF - Facelet Tags
- JSF - Convertor Tags
- JSF - Validator Tags
- JSF - DataTable
- JSF - Composite Components
- JSF - Ajax
- JSF - Event Handling
- JSF - JDBC Integration
- JSF - Spring Integration
- JSF - Expression Language
- JSF - Internationalization
- JSF Useful Resources
- JSF - Quick Guide
- JSF - Useful Resources
- JSF - Discussion
JSF - Custom Converter
We can create our own Custom convertor in JSF.
Defining a custom converter in JSF is a three-step process.
Step | Description |
---|---|
1 | Create a converter class by implementing javax.faces.convert.Converter interface. |
2 | Implement getAsObject() and getAsString() methods of above interface. |
3 | Use Annotation @FacesConvertor to assign a unique id to the custom convertor. |
Step 1: Create a Converter Class : UrlConverter.java
public class UrlConverter implements Converter { ... }
Step 2: Implement Converter Interface Methods : UrlConverter.java
Create a simple class to store data: UrlData. This class will store a URL string.
public class UrlData { private String url; public UrlData(String url) { this.url = url; } ... }
Use UrlData in getAsObject method.
public class UrlConverter implements Converter { @Override public Object getAsObject(FacesContext facesContext, UIComponent component, String value) { ... UrlData urlData = new UrlData(url.toString()); return urlData; } @Override public String getAsString(FacesContext facesContext, UIComponent component, Object value) { return value.toString(); } }
Step 3: Annotate to Register the Convertor : UrlConverter.java
@FacesConverter("com.tutorialspoint.test.UrlConverter") public class UrlConverter implements Converter { }
Use the Convertor in JSF Page
<h:inputText id = "urlInput" value = "#{userData.data}" label = "URL" > <f:converter converterId = "com.tutorialspoint.test.UrlConverter" /> </h:inputText>
Example Application
Let us create a test JSF application to test the above tag.
Step | Description |
---|---|
1 | Create a project with a name helloworld under a package com.tutorialspoint.test as explained in the JSF - First Application chapter. |
2 | Create UrlData.java under package com.tutorialspoint.test as explained below. |
3 | Create UrlConvertor.java as a converter under package com.tutorialspoint.test as explained below. |
4 | Create UserData.java as a managed bean under package com.tutorialspoint.test as explained below. |
5 | Modify home.xhtml as explained below. Keep rest of the files unchanged. |
6 | Create result.xhtml in the webapps directory as explained below. |
7 | Compile and run the application to make sure the business logic is working as per the requirements. |
8 | Finally, build the application in the form of war file and deploy it in Apache Tomcat Webserver. |
9 | Launch your web application using appropriate URL as explained below in the last step. |
UrlData.java
package com.tutorialspoint.test; public class UrlData { private String url; public UrlData(String url) { this.url = url; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public String toString() { return url; } }
UrlConvertor.java
package com.tutorialspoint.test; 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.tutorialspoint.test.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); } UrlData urlData = new UrlData(url.toString()); return urlData; } @Override public String getAsString(FacesContext facesContext, UIComponent component, Object value) { return value.toString(); } }
UserData.java
package com.tutorialspoint.test; import java.io.Serializable; import javax.faces.bean.ManagedBean; import javax.faces.bean.SessionScoped; @ManagedBean(name = "userData", eager = true) @SessionScoped public class UserData implements Serializable { private static final long serialVersionUID = 1L; public UrlData data; public UrlData getData() { return data; } public void setData(UrlData data) { this.data = data; } }
home.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"> <h:head> <title>JSF tutorial</title> </h:head> <h:body> <h2>Custom Converter Example</h2> <h:form> <h:inputText id = "urlInput" value = "#{userData.data}" label = "URL" > <f:converter converterId = "com.tutorialspoint.test.UrlConverter" /> </h:inputText> <h:commandButton value = "submit" action = "result"/> <h:message for = "urlInput" style = "color:red" /> </h:form> </h:body> </html>
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:f = "http://java.sun.com/jsf/core" xmlns:h = "http://java.sun.com/jsf/html" xmlns:ui = "http://java.sun.com/jsf/facelets"> <h:body> <h2>Result</h2> <hr /> #{userData.data} </h:body> </html>
Once you are ready with all the changes done, let us compile and run the application as we did in JSF - First Application chapter. If everything is fine with your application, this will produce the following result.
![JSF custom converter](/jsf/images/jsf_customconverter_result.jpg)
Enter any invalid value and press Submit button. See the following error message.
![JSF custom converter1](/jsf/images/jsf_customconverter_result1.jpg)
Enter any valid value and press Submit button. See the following result.
![JSF custom converter2](/jsf/images/jsf_customconverter_result2.jpg)
jsf_convertor_tags.htm
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