Building reactive applications using asynchronous servlets

Servlets are probably one of most well-known Java EE technologies (perhaps even the most known). Actually, servlets existed even before J2EE became a real specification.

This recipe will show you how to use servlets asynchronously.

Getting ready

Let's first add our Java EE 8 dependency:

    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-api</artifactId>
        <version>8.0</version>
        <scope>provided</scope>
    </dependency>

How to do it...

1. First, we create a User POJO:

public class User implements Serializable{

    private Long id;
    private String name;

    public User(long id, String name){
        this.id = id;
        this.name = name;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName...