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Create simple custom Converter implementation class in JSF

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Custom Converter Class Implementation

This article explains the simple Converter class implementation. Converter class is used for converting any given input to the desired output format or with any business logic to the input values.

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This example also includes the PhaseListener to identify in which JSF lifecycle phase the convertion happens.

JSP File (index.jsp)

<%@taglib prefix="f" uri="http://java.sun.com/jsf/core"%>
<%@taglib prefix="h" uri="http://java.sun.com/jsf/html"%>
<html>
    <body>
        <f:view>
            <h:form>
                <h:inputText value="#{jsfBean.field}">
                    <f:converter converterId="customConverter"/>
                </h:inputText>
                <h:commandButton action="#{jsfBean.submit}" value="Submit">
                    <f:phaseListener binding="#{jsfBean.phaseListenerImpl}" type="javabeat.jsf.PhaseListenerImpl"/>
                </h:commandButton>
            </h:form>
        </f:view>
    </body>
</html>

JavaBean (JavaBeatJsfBean.java)

package javabeat.jsf;

import javax.faces.event.ActionEvent;

/**
 * source : www.javabeat.net
 */
public class JavaBeatJsfBean {

    private String field;
    private CustomConverter customConverter;
    private PhaseListenerImpl phaseListenerImpl;

    public PhaseListenerImpl getPhaseListenerImpl() {
        return phaseListenerImpl;
    }

    public void setPhaseListenerImpl(PhaseListenerImpl phaseListenerImpl) {
        this.phaseListenerImpl = phaseListenerImpl;
    }

    public CustomConverter getCustomConverter() {
        return customConverter;
    }

    public void setCustomConverter(CustomConverter customConverter) {
        this.customConverter = customConverter;
    }

    public String getField() {
        return field;
    }

    public void setField(String field) {
        this.field = field;
    }

    public String submit() {
        System.out.println(this.field);
        return "success";
    }
}

CustomConverter.java

 package javabeat.jsf;

import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
/**
 * source : www.javabeat.net
 */
public class CustomConverter implements Converter{

 /**
 * This method used for getting the input and process and convert.
 */
 public Object getAsObject(FacesContext arg0, UIComponent arg1, String value) {
 System.out.println("Input from the user : "+value);
 System.out.println("Use custom convert logic and process the input");
 return "converted Value";
 }

 /**
 * This method used for return the converted value to the user.
 */
 public String getAsString(FacesContext arg0, UIComponent arg1, Object value) {
 System.out.println("Value to be displayed to the user"+value);
 String output = (String)value;
 return output;
 }
}

PhaseListenerImpl.java

package javabeat.jsf;

import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
/**
 * source : www.javabeat.net
 */
public class PhaseListenerImpl implements PhaseListener{
 public void afterPhase(PhaseEvent event) {
 System.out.println("After Executing " + event.getPhaseId());
 }
 public void beforePhase(PhaseEvent event) {
 System.out.println("Before Executing " + event.getPhaseId());
 }
 public PhaseId getPhaseId() {
 return PhaseId.ANY_PHASE;
 }
}

faces-config.xml

<?xml version='1.0' encoding='UTF-8'?>
<faces-config version="1.2"
    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_1_2.xsd">
    <managed-bean>
        <managed-bean-name>jsfBean</managed-bean-name>
        <managed-bean-class>javabeat.jsf.JavaBeatJsfBean</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
    </managed-bean>
    <converter>
        <description>A Converter</description>
        <converter-id>customConverter</converter-id>
        <converter-class>
        javabeat.jsf.CustomConverter
        </converter-class>
    </converter>
</faces-config>

Output in the command prompt

Before Executing RENDER_RESPONSE 6
After Executing RENDER_RESPONSE 6
Before Executing APPLY_REQUEST_VALUES 2
After Executing APPLY_REQUEST_VALUES 2
Before Executing PROCESS_VALIDATIONS 3
Input from the user : input Value
Use custom convert logic and process the input
After Executing PROCESS_VALIDATIONS 3
Before Executing UPDATE_MODEL_VALUES 4
After Executing UPDATE_MODEL_VALUES 4
Before Executing INVOKE_APPLICATION 5
converted Value
After Executing INVOKE_APPLICATION 5
Before Executing RENDER_RESPONSE 6
Value to be displayed to the userconverted Value
After Executing RENDER_RESPONSE 6

About Krishna Srinivasan

He is Founder and Chief Editor of JavaBeat. He has more than 8+ years of experience on developing Web applications. He writes about Spring, DOJO, JSF, Hibernate and many other emerging technologies in this blog.