apply plugin: 'eclipse'

apply plugin: 'war'
apply from: 'https://raw.github.com/akhikhl/gretty/master/pluginScripts/gretty.plugin'

gretty {
    port = 8080
    servletContainer = 'jetty9'
}

repositories {
    mavenCentral()
}

dependencies {
    compile group: "com.sun.faces", name: "jsf-api", version: "2.2.8"
    compile group: "com.sun.faces", name: "jsf-impl", version: "2.2.8"
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app
    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-app_3_0.xsd"
    version="3.0">

    <display-name>JavaServerFaces</display-name>

    <!-- Change to "Production" when you are ready to deploy -->
    <context-param>
        <param-name>javax.faces.PROJECT_STAGE</param-name>
        <param-value>Development</param-value>
    </context-param>

    <!-- JSF mapping -->
    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!-- Map these files with JSF -->
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>*.jsf</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>*.faces</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>*.xhtml</url-pattern>
    </servlet-mapping>

</web-app>

<faces-config
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd"
    version="2.2">
</faces-config>

Caused by: java.lang.IllegalStateException: Could not find backup for factory javax.faces.context.FacesContextFactory.
        at javax.faces.FactoryFinderInstance.getFactory(FactoryFinderInstance.java:500) ~[na:na]
        at javax.faces.FactoryFinder.getFactory(FactoryFinder.java:287) ~[na:na]
        at javax.faces.webapp.FacesServlet.init(FacesServlet.java:350) ~[na:na]
        at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:612) ~[jetty-servlet-9.2.10.v20150310.jar:9.2.10.v20150310]
        ... 46 common frames omitted