Exception in thread "main" java.lang.NullPointerException
at yPray.services.TerminalTeamImpl.add(TerminalTeamImpl.java:25)
at yPray.Application.main(Application.java:13)

@Override
public void add(Team team) {
    Session session = HibernateUtil.getSessionFactory().openSession();
    Transaction tx = session.beginTransaction();
    session.save(team);
    tx.commit();
    session.close();
}

@Entity
@Table(name = "teams")
public class Team {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int idTeam;

@Column
private String teamTag;

@Column
private int score;

public Team(){}
public Team(String teamTag){
    this.teamTag = teamTag;
}
// getters and setter

@Service
public class TerminalTeamImpl implements TerminalTeam {

@Resource
private TeamDaoImpl teamDao;

@Override
public void add(Team team) {
    teamDao.add(team);
}

public class HibernateUtil {
private static SessionFactory sessionFactory;

private HibernateUtil(){}

public static SessionFactory getSessionFactory(){
    if (sessionFactory == null) {
        try{
            Configuration configuration = new Configuration().configure();
            configuration.addAnnotatedClass(Team.class);
            configuration.addAnnotatedClass(Player.class);
            StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties());
            sessionFactory = configuration.buildSessionFactory(builder.build());
        }catch (Exception e) {
            System.out.println("Exception!!! " + e);
        }
    }
    return sessionFactory;
 }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
    <property
name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property
name="hibernate.connection.url">jdbc:mysql://127.0.0.1:3306/test</property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.connection.password">password</property>
    <property name="hibernate.connection.pool_size">1</property>
    <property
name="hibernate.current_session_context_class">thread</property>
    <property name="hibernate.show_sql">true</property>
    <property
name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
</session-factory>
</hibernate-configuration>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>6</source>
                <target>6</target>
            </configuration>
        </plugin>
    </plugins>
</build>
<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.12</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.3.6.Final</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot</artifactId>
        <version>2.0.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.9.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>5.0.9.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>javax.annotation</groupId>
        <artifactId>javax.annotation-api</artifactId>
        <version>1.3.2</version>
    </dependency>
</dependencies>

public class Application {
public static void main(String[] args) {
    Team navi = new Team("Navi");
    TerminalTeamImpl team = new TerminalTeamImpl();
    team.add(navi);

 }
}