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POUsing CDI (Context & Dependency Injection) backing beans instead of Managed Beans
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  1. POUsing CDI (Context & Dependency Injection) backing beans instead of Managed Beans
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    copied!<p>I rode that is recommended to use CDI beans as backing beans instead of JSF managed beans.</p> <p>So i decided to create a little example, to understand how it works, for a <strong>@RequestScopedBean</strong>:</p> <p>-instead of using <strong>@ManagedBean("beanName")</strong> ,i use <strong>@Named("beanName")</strong> </p> <p>-instead of using <strong>javax.faces.bean.RequestScopped</strong> i use <strong>javax.enterprise.context.RequestScoped;</strong></p> <p>The demo program is very simple, i have a field and a submit button, when the user inputs something and the page is refreshed, the inputed value is not displayed anymore(It last while the request lasts right?). I think i did everything ok, but i get an exception that says:</p> <blockquote> <p>WARNING: StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception javax.el.PropertyNotFoundException: /index.xhtml @19,47 value="#{cdiBean.passedValue}": Target Unreachable, identifier 'cdiBean' resolved to null</p> </blockquote> <p>This is how my program looks like:</p> <p><strong>index.xhtml</strong></p> <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; &lt;html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core"&gt; &lt;h:head&gt; &lt;title&gt;RequestScope demo CDI(Component Dependency Injection)&lt;/title&gt; &lt;/h:head&gt; &lt;h:body&gt; &lt;h:form&gt; &lt;h3&gt;RequestScope demo CDI(Component Dependency Injection)&lt;/h3&gt; &lt;h:inputText value="#{cdiBean.passedValue}"/&gt; &lt;br/&gt; &lt;h:commandButton value="submit" action="index"/&gt; &lt;/h:form&gt; &lt;/h:body&gt; &lt;/html&gt; </code></pre> <p><strong>DemoBB.java</strong></p> <pre><code>package backingbeans; import javax.enterprise.context.RequestScoped; import javax.inject.Named; @Named("cdiBean")//The Named anotation indicates that this is a CDI bean @RequestScoped//If we use CDI beans the @RequestScoped annotation must come from: javax.enterprise.context.RequestScoped; public class DemoBB { //This value will be saved on the session only until the server responds to the request private String passedValue; public String getPassedValue() { return passedValue; } public void setPassedValue(String passedValue) { this.passedValue = passedValue; } } </code></pre> <p>-Where is my mistake?</p> <p>-What is the advantage of using this approach? I still don't understand that.</p>
 

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