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- 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
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- JSF - Discussion
JSF - Custom Validator
We can create our own Custom validator in JSF.
Defining a custom validator in JSF is a three-step process.
Step | Description |
---|---|
1 | Create a validator class by implementing javax.faces.validator.Validator interface. |
2 | Implement validate() method of the above interface. |
3 | Use Annotation @FacesValidator to assign a unique ID to the custom validator. |
Step 1: Create a Validator Class : UrlValidator.java
public class UrlValidator implements Validator { ... }
Step 2: Implement Validator Interface Methods : UrlValidator.java
public class UrlValidator implements Validator { @Override public void validate(FacesContext facesContext, UIComponent component, String value) throws ValidatorException { ... } }
Step 3: Annotate to Register the Validator : UrlValidator.java
@FacesValidator("com.tutorialspoint.test.UrlValidator") public class UrlValidator implements Validator { }
Use the validator in JSF page
<h:inputText id="urlInput" value="#{userData.data}" label="URL" > <f:validator validatorId="com.tutorialspoint.test.UrlValidator" /> </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 UrlValidator.java as a converter under package com.tutorialspoint.test as explained below. |
3 | Create UserData.java as a managed bean under package com.tutorialspoint.test as explained below. |
4 | Modify home.xhtml as explained below. Keep rest of the files unchanged. |
5 | Create result.xhtml in the webapps directory as explained below. |
6 | Compile and run the application to make sure business logic is working as per the requirements. |
7 | Finally, build the application in the form of war file and deploy it in Apache Tomcat Webserver. |
8 | Launch your web application using appropriate URL as explained below in the last step. |
UrlValidator.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.validator.FacesValidator; import javax.faces.validator.Validator; import javax.faces.validator.ValidatorException; @FacesValidator("com.tutorialspoint.test.UrlValidator") public class UrlValidator implements Validator { @Override public void validate(FacesContext facesContext, UIComponent component, Object value) throws ValidatorException { StringBuilder url = new StringBuilder(); String urlValue = value.toString(); if(!urlValue.startsWith("http://", 0)) { url.append("http://"); } url.append(urlValue); try { new URI(url.toString()); } catch (URISyntaxException e) { FacesMessage msg = new FacesMessage("URL validation failed","Invalid URL format"); msg.setSeverity(FacesMessage.SEVERITY_ERROR); throw new ValidatorException(msg); } } }
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 String data; public String getData() { return data; } public void setData(String 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 Validator Example</h2> <h:form> <h:inputText id = "urlInput" value = "#{userData.data}" label = "URL" > <f:validator validatorId = "com.tutorialspoint.test.UrlValidator" /> </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 validator](/jsf/images/jsf_customvalidator_result.jpg)
Enter any invalid value and press Submit button. See the following error message.
![JSF custom validator1](/jsf/images/jsf_customvalidator_result1.jpg)
Enter any valid value and press Submit button. Following will be the ouput.
![JSF custom validator2](/jsf/images/jsf_customvalidator_result2.jpg)
jsf_validation_tags.htm
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