SpringMVC Controller doesn't work

Question

I am learning SpringMVC and try to build a HelloWorld webapp.
I build this project with eclipse using the code from Sping in Action 4th Edition ,
but when I test it on my browser by visiting http://localhost:8080/homepage
I got 404 error.


And the most weired thing is, if I test the controller using MockMvc (method provided by Spring in Action , it will pass the test.
SO I am wondering where did I do wrong?

The structure of my project:

SpittrWebAppInitializer.java:

package spittr.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class SpittrWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        // TODO Auto-generated method stub
        return new Class<?>[] {RootConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        // TODO Auto-generated method stub
        return new Class<?>[] {WebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        // TODO Auto-generated method stub
        return new String[]{"/"};
    }

}

WebConfig.java

package spittr.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan("spitter.web")
public class WebConfig extends WebMvcConfigurerAdapter {

    @Bean
    public ViewResolver viewRseolver(){
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){
        configurer.enable();
    }

}

RootConfig.java

package spittr.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;

@Configuration
@ComponentScan(basePackages={"spitter"},excludeFilters={@Filter(type=FilterType.ANNOTATION,value=EnableWebMvc.class)})
public class RootConfig {

}

HomeController.java

package spittr.web;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping({"/","/homepage"})
public class HomeController {

    @RequestMapping(method=RequestMethod.GET)
    public String home(){
        return "home";
    }

}

Answer 1

@ComponentScan("spitter.web")

Your package name is spittr.web

@ComponentScan(basePackages={"spitter"}

Same here

ADDED EXPLANATION:

@ComponentScan is looking for @Component (including @Repository, @Service and @Controller) annotated classes on the provided package and all its subpackages in order to add them to the Spring Context. While the provided packages don't exist, Spring doesn't find your controller so it doesn't create it.

It works when you test it because you are using it explicitly on your tests.