JSF - First steps - Bean doesnt work_问答_开发者

Im moving first steps into JSF framework. I so make these jsp/bean :

index.jsp :

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">
   <%@ taglib prefix="f" uri="http://java.sun.com/jsf/core" %>
   <%@ taglib prefix="h" uri="http://java.sun.com/jsf/html" %>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Home</title>
    </head>
    <body>
        <f:view>
            <h:form>
                <h:outputText value="Inserisci il tuo nome" />
                <h:inputText value="#{utente.nome}" />
                <h:commandButton value="Cliccami" action="avanti" />
            </h:form>
        </f:view>
     </body>
</html>

pagina1.jsp :

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">
    <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
    <%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Login Page</title>
    </head>
    <body>
        <f:view>
            <h:form id="LoginApplication">
                <h:panelGrid id="lpg" columns="2">
                    <h:outputText value="Benvenuto nella tua prima pagina JSP " />
                    <h:outputText value="#{utente.nome}" />
                <开发者_运维百科;/h:panelGrid>
            </h:form>
        </f:view>
     </body>
</html>

user.java

package myPack;

public class user{
    private String nome;
    public user(){}

    public String getNome(){
        return nome;
    }
    public void setNome(String nome) {
        this.nome=nome;
    }
}

faces.config.xml

<?xml version='1.0' encoding='UTF-8'?>

<!DOCTYPE faces-config PUBLIC
  "-//Sun Microsystems, Inc.//DTD JavaServer Faces Config 1.1//EN"
  "http://java.sun.com/dtd/web-facesconfig_1_1.dtd">

<!-- =========== FULL CONFIGURATION FILE ================================== -->

<faces-config>
    <navigation-rule>
        <from-view-id>/index.jsp</from-view-id>
        <navigation-case>
            <from-outcome>avanti</from-outcome>
            <to-view-id>/pagina1.jsp</to-view-id>
        </navigation-case>
    </navigation-rule>

    <managed-bean>
        <managed-bean-name>utente</managed-bean-name>
        <managed-bean-class>myPack.user</managed-bean-class>

        <managed-bean-scope>request</managed-bean-scope>
    </managed-bean>
</faces-config>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <context-param>
        <param-name>javax.faces.CONFIG_FILES</param-name>
        <param-value>/WEB-INF/faces-config.xml</param-value>
    </context-param>

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

    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>

    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>

    <welcome-file-list>
        <welcome-file>faces/index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

and i have these problems : 1 - on the input text i see the #{utente.nome} printed before click on the button (why? at the moment i don't have nothing on the bean). 2 - when i send it to the server, nothing happen, and the string "#{utente.nome}" will printed. Why?

This can happen when the web.xml is not properly configured as at least Servlet 2.4. The EL expressions (those #{} things) won't be evaluated then. Since you're using the vintage JSF 1.1, I bet that you're using a vintage servletcontainer as well. Ensure that it supports Servlet 2.4 and ensure that the web.xml is declared at least as:

<web-app 
    xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
    version="2.4">

Or if you're using a Servlet 2.5 compatible container, then ensure that web.xml is declared as follows:

<web-app 
    xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd"
    version="2.5">

(and consider upgrading JSF to 1.2 or, better, 2.0)

You also need to ensure that you don't have any servletcontainer specific libraries like servlet-api.jar, j2ee.jar, javaee.jar, jsp-api.jar, etc..etc.. wandering around in webapp's /WEB-INF/lib folder or even worse, in the JRE/lib/ext folder. The /WEB-INF/lib folder should contain only the JSF libraries (and any other libraries specific to the webapp itself). The JRE/lib/ext folder should be kept untouched.