Using Server Push to make objects available beforehand

One of the most important new features of Servlet 4.0 is the HTTP/2.0 support. It brings another cool and reliable feature—the Server Push.

This recipe will show you how to use Server Push in a filter and push the resources needed in every request that we want.

Getting ready

We should first add the dependencies needed:

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.0-b07</version>
            <scope>provided</scope>
        </dependency> 
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>

How to do it...

1. We first create UserServlet that calls user.jsp:

@WebServlet(name = "UserServlet...