Using transactions with asynchronous tasks

Using asynchronous tasks could be already a challenge: what if you need to add some spice and add a transaction to it?

Usually, a transaction means something like code blocking. Isn't it awkward to combine two opposing concepts? Well, it's not! They can work together nicely, as this recipe will show you.

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. Let's first create a User POJO:

public class User {

    private Long id;
    private String name;

    public Long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name...