Here is a reference for the most commonly used Java Servlet annotations:

1. @WebServlet: Used to define a servlet and map it to a URL pattern.

@WebServlet(name = "MyServlet", urlPatterns = { "/hello" })
public class MyServlet extends HttpServlet {
  // ...
}

2. @WebFilter: Used to define a filter and map it to a URL pattern.

@WebFilter(filterName = "MyFilter", urlPatterns = { "/*" })
public class MyFilter implements Filter {
  // ...
}

3. @WebListener: Used to define a listener for various events in the servlet container.

@WebListener
public class MyServletContextListener implements ServletContextListener {
  // ...
}

4. @WebInitParam: Used to define initialization parameters for a servlet or filter.

@WebServlet(name = "MyServlet", urlPatterns = { "/hello" }, initParams = {
  @WebInitParam(name = "foo", value = "bar")
})
public class MyServlet extends HttpServlet {
  // ...
}

5. @MultipartConfig: Used to configure a servlet to handle HTTP multipart requests.

@MultipartConfig(location = "/path/to/upload/directory", maxFileSize = 10 * 1024 * 1024, maxRequestSize = 50 * 1024 * 1024)
public class FileUploadServlet extends HttpServlet {
  // ...
}

6. @HttpMethodConstraint: Used to define constraints on the HTTP methods that a servlet or filter can handle.

@HttpMethodConstraint(value = "GET", rolesAllowed = { "admin" })
@WebServlet(name = "MyServlet", urlPatterns = { "/hello" })
public class MyServlet extends HttpServlet {
  // ...
}

7. @ServletSecurity: Used to define security constraints on a servlet.

@ServletSecurity(@HttpConstraint(rolesAllowed = {"admin"}))
@WebServlet(name = "MyServlet", urlPatterns = { "/hello" })
public class MyServlet extends HttpServlet {
  // ...
}

These annotations can help you configure your servlets, filters, and listeners in a more concise and readable way than with the traditional web.xml deployment descriptor. For more information, you can refer to the Java Servlet API documentation.