How to inject Spring beans into Servlets

This can be achieved in 3 simple steps:

1. Implement HttpRequestHandler

First of all, your servlet class must implement the org.springframework.web.HttpRequestHandler interface and provide an implementation for the handleRequest() method just like you would override doPost().

2. Declare the servlet as a Spring Bean

You can do this by either adding the @Component("myServlet") annotation to the class, or declaring a bean with a name myServlet in applicationContext.xml.

@Component("myServlet")
public class MyServlet implements HttpRequestHandler {
...

3. Declare in web.xml a servlet named exactly as the Spring Bean

The last step is to declare a new servlet in web.xml that will have the same name as the previously declared Spring bean, in our case myServlet. The servlet class must be org.springframework.web.context.support.HttpRequestHandlerServlet.

<servlet>
    <display-name>MyServlet</display-name>
    <servlet-name>myServlet</servlet-name>
    <servlet-class>
        org.springframework.web.context.support.HttpRequestHandlerServlet
    </servlet-class>
</servlet>
 
<servlet-mapping>
    <servlet-name>myServlet</servlet-name>
    <url-pattern>/myurl</url-pattern>
</servlet-mapping>

Now you are ready to inject any spring bean in your servlet class.

@Component("myServlet")
public class MyServlet implements HttpRequestHandler {
        
        @Autowired
        private MyService myService;