Spring and ServletContextListener - spring

Question

I read some articles and posts here about
#Autowired
ServletContext context;
Of my realization of ServletContextListener to #Controller. But I got a long exception when run it:
org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'trendsoftCtrl':
Unsatisfied dependency expressed through field 'context':
No qualifying bean of type [javax.servlet.ServletContext] found for dependency [javax.servlet.ServletContext]:
expected at least 1 bean which qualifies as autowire candidate for this dependency.
Dependency annotations:
{#org.springframework.beans.factory.annotation.Autowired(required=true)};
nested exception is
org.springframework.beans.factory.NoSuchBeanDefinitionException:
No qualifying bean of type [javax.servlet.ServletContext] found for dependency [javax.servlet.ServletContext]:
expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations:
{#org.springframework.beans.factory.annotation.Autowired(required=true)}
Here are my classes.
#WebListener
public class TRSCListner implements ServletContextListener {
#Override
public void contextInitialized(ServletContextEvent event) {
ServletContext context = event.getServletContext();
String beanFileName = context.getInitParameter("springBeans");
GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
ctx.load(beanFileName);
ctx.refresh();
NewsDao newsDao = ctx.getBean("newsDao", NewsDao.class);
context.setAttribute("appContext", ctx);
context.setAttribute("dao", newsDao);
}
#Override
public void contextDestroyed(ServletContextEvent event) {
ServletContext context = event.getServletContext();
GenericXmlApplicationContext ctx = (GenericXmlApplicationContext) context.getAttribute("appContext");
ctx.close();
}
}
And another
#Controller
public class TrendsoftCtrl {
#Autowired
ServletContext context;
#RequestMapping ("/welcome")
public ModelAndView helloWorld() {
NewsDao newsDao = (NewsDao) context.getAttribute("dao");
List<News> news = newsDao.getAll();
StringBuilder message = new StringBuilder();
for (News n : news) {
message.append(n.getCategory().getName() + "<br>");
message.append(n.getName() + "<br>");
message.append(n.getData() + "<br><br>");
}
return new ModelAndView("welcome", "news", message.toString());
}
public ServletContext getContext() {
return context;
}
public void setContext(ServletContext context) {
this.context = context;
}
}

Answer 1

By default, the #Autowired will perform the dependency checking to make sure the property has been wired properly. When Spring can’t find a matching bean to wire, it will throw an exception. To fix it, you can disable this checking feature by setting the “required” attribute of #Autowired to false.
#Autowired(required=false)
Even if Spring can’t find a matching bean, it will leave the person property unset.