@Entity
@Table(name = "employees")
public class Employee {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "name")
private String name;
// getters and setters
}
public List<Employee> getAllEmployees() {
EntityManagerFactory emf = Persistence.createEntityManagerFactory("my-persistence-unit");
EntityManager em = emf.createEntityManager();
TypedQuery<Employee> query = em.createQuery("SELECT e FROM Employee e", Employee.class);
return query.getResultList();
}
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_2.xsd"
version="2.2">
<persistence-unit name="my-persistence-unit" transaction-type="RESOURCE_LOCAL">
<provider>org.jpox.PersistenceProviderImpl</provider>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/mydb"/>
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.jdbc.password" value="password"/>
</properties>
</persistence-unit>
</persistence>
public class EmployeeMapper {
public List<Employee> getAllEmployees() {
SqlSessionFactory sessionFactory = getSqlSessionFactory();
try (SqlSession session = sessionFactory.openSession()) {
EmployeeMapper mapper = session.getMapper(EmployeeMapper.class);
return mapper.getAllEmployees();
}
}
@Select("SELECT * FROM employees")
List<Employee> getAllEmployees();
private SqlSessionFactory getSqlSessionFactory() {
String resource = "mybatis-config.xml";
try (InputStream inputStream = Resources.getResourceAsStream(resource)) {
return new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
throw new RuntimeException("Error initializing MyBatis.", e);
}
}
}
<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mydb"/>
<property name="username" value="root"/>
<property name="password" value="password"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper class="com.example.EmployeeMapper"/>
</mappers>
</configuration>
