"@Bean methods are valid only when declared within a @Configuration annotated class" error

Question

I am trying to make a Hello World app using Spring MVC and JavaConfigs instead of XML files. I read that you can declare a bean using @Bean if the class is annotated with @Configuration. I have a class annotated with @Configuration and a method inside annotated with @Bean.

I'm getting an error message within IntelliJ 12 (red underline error):

@Bean methods are valid only when declared within a @Configuration annotated class

And the following error message on Tomcat 7.0.37 startup:

SEVERE: Context initialization failed
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: file [S:\dropbox\Shared Folders\Majerus Eric (BBY)\SpringMVCBarebones\target\SpringMVCBarebones\WEB-INF\classes\com\springapp\mvc\WebAppConfig.class]; nested exception is java.lang.annotation.AnnotationFormatError: Invalid default: public abstract org.springframework.beans.factory.annotation.Autowire org.springframework.config.java.annotation.Bean.autowire()

WebAppConfig

package com.springapp.mvc;

import org.springframework.config.java.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
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;

@EnableWebMvc
@ComponentScan("com.springapp.mvc")
@Configuration
public class WebAppConfig extends WebMvcConfigurerAdapter {

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

    @Bean
    public InternalResourceViewResolver getInternalResourceViewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/pages/");
        resolver.setSuffix(".jsp");
        return resolver;
    }
}

WebAppInitializer

package com.springapp.mvc;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;


import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;

public class WebAppInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext container) throws ServletException {

        // Create the 'root' Spring application context.
        AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();

        // Manage the lifecycle of the root application context.
        container.addListener(new ContextLoaderListener(rootContext));

        // Create the dispatcher servlet's Spring application context
        AnnotationConfigWebApplicationContext dispatcherContext = new AnnotationConfigWebApplicationContext();
        dispatcherContext.register(WebAppConfig.class);

        ServletRegistration.Dynamic dispatcher = container.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));
        dispatcher.setLoadOnStartup(1);
        dispatcher.addMapping("/");
    }
}

As an example, I used this tutorial: Migrate Spring MVC servlet.xml to Java Config and also Spring documentation on WebAppInitializer.

My git repo is hosted on Bitbucket here.

Answer 1

Taking a look at your pom, you have spring-javaconfig added. spring-javaconfig has been merged into spring 3.X so you should not need it. Remove it and it should run fine.