Injecting Spring @Resource into a Servlet

Question

I have the following piece of code, which I modeled on this answer:

public class DeployerServlet extends HttpServlet {
    @Resource
    Engine engine;

    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this, config.getServletContext());
    }

    // ...
}

But the servlet is not even correctly instantiated. When creating an instance, Tomcat tries to look up the name com.example.DeployerServlet/engine in JNDI which results in an exception,

SEVERE: Allocate exception for servlet Deploy Servlet
javax.naming.NameNotFoundException: Name com.example.DeployerServlet is not bound in this Context

So, what is the recommended way to inject a Spring bean into a servlet?

It depends. Do you mind if you get dependencies to spring classes in your servlet? — mael, Aug 05 '13 at 14:38
I am already fine with `SpringBeanAutowiringSupport` in my servlet, so I guess no problem. But it would be nice to have the declarative `@Resource` instead of a direct `applicationContext.getBean()` call. — Saintali, Aug 05 '13 at 14:41
Because the Container is responsible for initializing the Servlet, you're forced to use the `SpringBeanAutowiringSupport` to achieve what you want. The Servlet is not managed by Spring. — Sotirios Delimanolis, Aug 05 '13 at 14:45
@SotiriosDelimanolis I get that, but the problem is, Tomcat interprets the `@Resource` as a JNDI lookup, and throws an exception before I have a chance to call `SpringBeanAutowiringSupport`. — Saintali, Aug 05 '13 at 14:49
Thanks, `@Autowired` worked! It's a shame that you cannot use the standard `@Resource` here. — Saintali, Aug 05 '13 at 15:00
Added an answer with a reference to JavaEE docs that should explain the behavior. — Sotirios Delimanolis, Aug 05 '13 at 15:24

score 1 · Accepted Answer · answered Aug 05 '13 at 15:22

1

The @Resource annotation is a JavaEE element. It's used to declare a reference to a resource. Although Spring can use it the same way it does with @Inject and @Autowired, in this case the servlet Container acts first. Just replace your @Resource with @Autowired.

answered Aug 05 '13 at 15:22

Sotirios Delimanolis

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Note there is slight difference between `@Autowired` and `@Resource`: the later binds beans by name first, then falls back to binding by type; the former binds exclusively by type, using name (as supplied by `@Qualifier` annotation) as a hint only (http://static.springsource.org/spring/docs/3.0.0.M3/reference/html/ch04s11.html). – Jerzyna Aug 19 '13 at 14:38

score -1 · Answer 2 · answered Aug 05 '13 at 14:35

-1

Seems to be your build is not properly done. clean your project and rebuild. Your issue will solve

answered Aug 05 '13 at 14:35

Ruchira Gayan Ranaweera

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I use Maven and have been getting this error consistently across multiple builds. Also I do not see how this could be a build problem, as obviously there is no such JNDI name. – Saintali Aug 05 '13 at 14:47

Injecting Spring @Resource into a Servlet

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