HibernateUtil.java

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

/**
 * Created by Ариорх on 27.05.2017.
 */
public class HibernateUtil {
    private static SessionFactory sessionFactory = null;

    static {
        Configuration cfg = new Configuration().configure();
        StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder()
                .applySettings(cfg.getProperties());
        sessionFactory = cfg.buildSessionFactory(builder.build());
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

Main.java

import org.hibernate.SessionFactory;

/**
 * Created by Ариорх on 27.05.2017.
 */
public class Main {
    public static void main(String[] args) {
        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
    }
}

main_resources_hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/test</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <property name="hbm2ddl.auto">update</property>
        <mapping class="models.User"/>
        <mapping class="models.Role"/>
        <mapping class="models.Order"/>
        <mapping class="models.Product"/>
        <mapping class="models.ProductCategory"/>


    </session-factory>
</hibernate-configuration>

Model.java

package models;

import javax.persistence.*;
import java.io.Serializable;


@MappedSuperclass
public abstract class Model implements Serializable {


    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "Id")

    private long id;

    public Model() {
    }

    public Model(long id) {
        this.id = id;
    }

    public long getId() {
        return id;
    }

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

Order.java

package models;

import javax.persistence.*;
import java.math.BigDecimal;

/**
 * Created by Ариорх on 28.05.2017.
 */
@Entity
@Table
public class Order extends Model {
    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "user_id", referencedColumnName = "id")
    private User user;
    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "product_id", referencedColumnName = "id")
    private Product product;
    @Column
    private int count;
    @Column
    private BigDecimal price;
    @Column
    private Boolean status;

    public Order() {
    }

    public Order(long id) {
        super(id);
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public Product getProduct() {
        return product;
    }

    public void setProduct(Product product) {
        this.product = product;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public Boolean getStatus() {
        return status;
    }

    public void setStatus(Boolean status) {
        this.status = status;
    }
}

Product.java

package models;

import javax.persistence.*;
import java.math.BigDecimal;

/**
 * Created by Ариорх on 28.05.2017.
 */
@Entity
@Table(name = "product")
public class Product extends Model {
    @Column
    private String title;
    @Column
    private BigDecimal price;
    @Column
    private String description;

    @ManyToOne (fetch = FetchType.LAZY)
    @JoinColumn(name = "product_category_id", referencedColumnName = "id")
    private ProductCategory productCategory;


    public Product() {
    }

    public Product(long id) {
        super(id);
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public ProductCategory getProductCategory() {
        return productCategory;
    }

    public void setProductCategory(ProductCategory productCategory) {
        this.productCategory = productCategory;
    }
}

ProductCategory.java

package models;

import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;

/**
 * Created by Ариорх on 28.05.2017.
 */
@Entity
@Table(name = "product_category")
public class ProductCategory extends Model {
    @Column
    private String title;
    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "parent_product_category", referencedColumnName = "id")
    private ProductCategory parentProductCategory;
    @OneToMany(mappedBy = "productCategory")
    private Set<Product> products = new HashSet<Product>();

    public ProductCategory() {
    }

    public ProductCategory(long id) {
        super(id);
    }

    @OneToMany(mappedBy = "productCategory")
    public Set<Product> getProducts() {
        return products;
    }

    public void setProducts(Set<Product> products) {
        this.products = products;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public ProductCategory getParentProductCategory() {
        return parentProductCategory;
    }

    public void setParentProductCategory(ProductCategory parentProductCategory) {
        this.parentProductCategory = parentProductCategory;
    }
}

Role.java

package models;

import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;

/**
 * Created by Ариорх on 27.05.2017.
 */
@Entity
@Table(name = "Role")
public class Role extends Model {

    @Column(name = "Title")
    private String title;
    @ManyToMany(mappedBy = "roles")
    private Set<User> users = new HashSet<User>();

    public Role() {
        super();
    }

    public Role(long id) {
        super(id);
    }

    public Set<User> getUsers() {
        return users;
    }

    public void setUsers(Set<User> users) {
        this.users = users;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

User.java

package models;

import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;

/**
 * Created by Ариорх on 27.05.2017.
 */
@Entity
@Table(name = "user")
public class User extends Model {
    @Column
    private int age;
    @Column
    private String firstName;
    @Column
    private String lastName;

    @ManyToMany
    @JoinTable(name = "user_role", joinColumns = {@JoinColumn(name = "user_id")},
            inverseJoinColumns = {@JoinColumn(name = "role_id")})
    private Set<Role> roles = new HashSet<Role>();

    public User() {
        super();
    }

    public User(long id) {
        super(id);
    }

    public Set<Role> getRoles() {
        return roles;
    }

    public void setRoles(Set<Role> roles) {
        this.roles = roles;
    }

    public int getAge() {
        return age;
    }

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

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

}