title: Spring Boot cannot find controller's mapping
body: <p><strong>DataController</strong> </p>
  
  <pre><code>package go.controller;
  @Controller
  public class DataController {
  
      @RequestMapping(value = "/", method = RequestMethod.GET)
      public String start(){
          return "index";
      }
  </code></pre>
  
  <p><strong>WebMvcConfig</strong> </p>
  
  <pre><code>package go.config;
  public class WebMvcConfig extends WebMvcConfigurerAdapter {
      @Override
      public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){
          configurer.enable();
      }
      @Bean
      public InternalResourceViewResolver viewResolver(){
          InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
          viewResolver.setPrefix("WEB-INF/pages");
          viewResolver.setSuffix(".jsp");
          return viewResolver;
      }
  
  }
  </code></pre>
  
  <p><strong>StaticResourceConfiguration</strong></p>
  
  <pre><code>package go.config;
  public class StaticResourceConfiguration extends WebMvcConfigurerAdapter {
      @Override
      public void addResourceHandlers(ResourceHandlerRegistry registry) {
          registry.addResourceHandler("/**").addResourceLocations("/**");
      }
  }
  </code></pre>
  
  <p>And I have <code>index.jsp</code> in <code>src/main/webapp/WEB-INF/pages/</code></p>
  
  <p>Why Spring Boot shows <code>404 Not found</code>?</p>