在Spring MVC中打印Hello World时出错

Question

I am making simple hello world in spring using MVC taking help from this site http://viralpatel.net/blogs/spring-3-mvc-create-hello-world-application-spring-3-mvc/

But I am getting error .

Here is my file : web.xml

   <?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    id="WebApp_ID" version="2.5">
    <display-name>Spring3MVC</display-name>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

    <servlet>
        <servlet-name>spring</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>*</url-pattern>
</servlet-mapping>
</web-app>

spring-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:mvc="http://www.springframework.org/schema/mvc" 
    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
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">


    <context:component-scan
        base-package="net.viralpatel.spring3.controller" />
        <mvc:annotation-driven />
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

controller

@Controller
public class HelloWorldController {

    @RequestMapping("/hello")
    public ModelAndView helloWorld() {

        String message = "Hello World, Spring 3.0!";
        System.out.println(message);
        return new ModelAndView("hello", "message", message);
    }

}

I download the code with above url and run

http:// * ** :8080/Spring3MVC/hello** http:// * ** :8080/Spring3MVC/index** http:// * ** :8080/Spring3MVC/hello.jsp** in all i am getting this error

getting error he requested resource (/Spring3MVC) is not available.

Answer 1

First, you're making a request to

/Spring3MVC

(assuming /Spring3MVC is your context path), whil your @Controller handler method is mapped to

/Spring3MVC/hello

Second, your @Controller isn't being registered. For that to happen, you need to add

<mvc:annotation-driven />

to your spring-servlet.xml context configuration while also adding the mvc namespace to your namespace declarations.

Start by reading the documentation , however long it is.

Answer 2

Your dispatcher servlet is mapping all * urls, and your endpoint uses /hello url, so try: http://***:8080/Spring3MVC/hello or http://***:8080/hello depending on your application server context settings

Also please add <mvc:annotation-driven /> to your context configuration to "turn-on" @Contoller annotation