User.java

public class User {

    private String name;
    private int age;

    public User(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @NotNull
    @Override
    public String toString() {
        return this.getClass().getName() +
                "(name=" + getName() + ", " +
                "age=" + getAge() + ")";
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }

        if (!User.class.isAssignableFrom(obj.getClass())) {
            return false;
        }

        final User other = (User) obj;
        if ((this.name == null) ?
                (other.name != null) :
                !this.name.equals(other.name)) {
            return false;
        }
        return this.age == other.age;
    }

    @Override
    public int hashCode() {
        int hash = 3;
        hash = 53 * hash + (this.name != null ? this.name.hashCode() : 0);
        hash = 53 * hash + this.age;
        return hash;
    }
}