[Spring] Problema con controller annotation

[fermat]

ciao!

sto cercando di usare i controller con le annotations.
questo il controller:

@Controller
@RequestMapping("/")
public class IndexController {

    @RequestMapping(method = RequestMethod.GET)
    public ModelAndView helloWorld(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView model = new ModelAndView("index");
        model.addObject("msg", "hello world");
        return model;
    }

}

questo il dispatcher-servlet.xml

<?xml version='1.0' encoding='UTF-8' ?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
    
    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver" >
        <property name="prefix">
            <value>/WEB-INF/jsp/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

</beans>

e infine l'applicationContext.xml:

<?xml version='1.0' encoding='UTF-8' ?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
    
    <context:component-scan base-package="com.mp" />

</beans>

nel web.xml ho messo così:

<listener>
        <!--<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>-->
        <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
    </listener>

ma ottengo sempre un HTTP Status 400.
da cosa può dipendere??

[fermat]

ho fatto un pò d'ordine diciamo.
questo il controller:

@Controller
public class IndexController {

    @RequestMapping(value = "/", method = RequestMethod.GET)
    public String home(Locale locale, Model model) {
        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
        String formattedDate = dateFormat.format(date);
        model.addAttribute("serverTime", formattedDate);
        return "index";
    }

}

questo il web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" 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-app_3_1.xsd">
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>redirect.jsp</welcome-file>
    </welcome-file-list>
</web-app>

e questo il dispatcher-servlet.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
   http://www.springframework.org/schema/beans     
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/context 
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:component-scan base-package="com.mp" />

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/" />
        <property name="suffix" value=".html" />
    </bean>

</beans>

la pagina index.jsp si trova dentro /WEB-INF/views
questo l'indirizzo a cui vado: http://localhost:8080/spring/index.html
ottengo questo errore:

HTTP Status 404 -type Status report
message 
description The requested resource is not available.
Apache Tomcat/8.0.9

la cosa strana è che non indica neanche la pagina che non trova!
problema di "contesto"??

[fermat]

ok modificando il controller così funziona:

@Controller
public class IndexController {

    @RequestMapping(value = "/index", method = RequestMethod.GET)
    public String index(Locale locale, Model model) {
        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
        String formattedDate = dateFormat.format(date);
        model.addAttribute("serverTime", formattedDate);
        return "index";
    }

}

mi sorge però una domanda.
il metodo deve ritornare una stringa che equivale al nome del file senza estensione.
ma che relazione c'è tra il nome del metodo e il valore di value passato come parametro a RequestMapping??