Spring configuration for webapps without spring MVC - spring

Question

I'm trying to configure my multi-module project for using Spring without Spring MVC.
Here is the project hierarchy :
brewspberry-rpm-parent
---- brewspberry-api (containing webservices)
---- brewspberry-core (containing services and DAOs)
---- brewspberry-webapp (containing web pages, servlets, ...)
brewspberry-core is a maven dependency of webapp.
What I try to do is being able to autowire core beans in webapp. I use Java-based configuration.
Here is my Spring webapp initializer :
public class SpringWebappInitializer extends
AbstractAnnotationConfigDispatcherServletInitializer implements
WebApplicationInitializer {
public void onStartup(ServletContext servletContext)
throws ServletException {
AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
rootContext.setServletContext(servletContext);
// rootContext.setConfigLocation("net.brewspberry.util");
rootContext.register(SpringCoreConfiguration.class);
//servletContext.addListener(new ContextLoaderListener(rootContext));
getWebAppContext(servletContext);
}
private void getWebAppContext(ServletContext servletContext) {
// now the config for the Dispatcher servlet
AnnotationConfigWebApplicationContext mvcContext = new AnnotationConfigWebApplicationContext();
// mvcContext.setConfigLocation("net.brewspberry.util.config");
mvcContext.register(SpringWebappConfiguration.class);
ServletRegistration.Dynamic dispatcher = servletContext.addServlet(
"DispatcherServlet", new DispatcherServlet(mvcContext));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("*.do");
}
#Override
protected Filter[] getServletFilters() {
return null; // new Filter[] { new AuthentificationFilter() };
}
#Override
protected Class<?>[] getRootConfigClasses() {
// TODO Auto-generated method stub
return null;
}
#Override
protected Class<?>[] getServletConfigClasses() {
// TODO Auto-generated method stub
return null;
}
#Override
protected String[] getServletMappings() {
// TODO Auto-generated method stub
return null;
}
}
The configuration class is :
#Configuration
#EnableWebMvc
#ComponentScan({ "net.brewspberry" })
public class SpringWebappConfiguration extends WebMvcConfigurerAdapter {
#Override
public void configureDefaultServletHandling(
DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
}
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("forward:/login.jsp");
}
#Bean(name = "viewResolver")
public InternalResourceViewResolver getViewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
}
I would like that servlets could inject services from Brewspberry-core module.
I tried a solution from a previous post in SO that consisted in creating an Abstract Servlet containing this :
#Override
public void init(ServletConfig arg0) throws ServletException {
// Autowire beans in webapp
final AutowireCapableBeanFactory autowireCapableBeanFactory = WebApplicationContextUtils
.getWebApplicationContext(servletContext)
.getAutowireCapableBeanFactory();
autowireCapableBeanFactory.autowireBean(this);
}
I tried several things but still I get a NullPointerException when getting servletContext :
from arg0.getServletContext()
by autowiring it
I precise that core configuration works in tests. The issue I got is with webapp to core configuration
Update
By removing overriden onStartup method and adding both config classes to getRootConfigClasses(), servletContext is created :
#Override
protected Class<?>[] getRootConfigClasses() {
return new Class<?>[]{SpringCoreConfiguration.class, SpringWebappConfiguration.class};
}

Answer 1

You are extending AbstractAnnotationConfigDispatcherServletInitializer but are trying very hard not to use the way it should be used.
Replace your class with the following
public class SpringWebappInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
#Override
protected Class<?>[] getRootConfigClasses() {
return new Class[] {SpringCoreConfiguration.class};
}
#Override
protected Class<?>[] getServletConfigClasses() {
return new Class[] {SpringWebappConfiguration.class};
}
#Override
protected String[] getServletMappings() {
return new String[] {"*.do"};
}
}
That will register all that is needed (including the proper servlet mapping) and will make the code for the servlet you already have work.
The main issue is the fact that you have overridden the onStartup method basicaly destroying all the features of the AbstractAnnotationConfigDispatcherServletInitializer. That already creates a ContextLoaderListener and a DispatcherServlet for you.