This example apply following technologies:
- Eclipse Oxygen 4.7
- MySQL 10.1.29-MariaDB (from xampp-win32-7.2.0-0-VC15-installer)
- JDK 1.8
- Hibernate 3.6.3
Nội dung chính
Hibernate 3 XML Mapping Project Structure
Create Hibernate 3 XML Mapping - MySQL Example
1. Create project "hibernate3-xml-example"
You can refer to tutorial how to create maven project in Eclipse?.
Update pom.xml file:
<dependencies> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>3.6.3.Final</version> </dependency> <dependency> <groupId>javassist</groupId> <artifactId>javassist</artifactId> <version>3.12.1.GA</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.20</version> </dependency> </dependencies>
2. Create table testdb.Employee
create table testdb.EMPLOYEE ( id INT NOT NULL auto_increment, first_name VARCHAR(20) default NULL, last_name VARCHAR(20) default NULL, salary INT default NULL, PRIMARY KEY (id) );
3. Create entity class
Create Employee.java as a POJO class.
File: Employee.java
package com.realtut.entity; public class Employee implements java.io.Serializable { private Integer id; private String firstName; private String lastName; private Integer salary; public Employee() { } public Employee(String firstName, String lastName, Integer salary) { this.firstName = firstName; this.lastName = lastName; this.salary = salary; } public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } public String getFirstName() { return this.firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return this.lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public Integer getSalary() { return this.salary; } public void setSalary(Integer salary) { this.salary = salary; } }
4. Create XML mapping file
File: Employee.hbm.xml
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.realtut.entity.Employee" table="employee" catalog="testdb"> <id name="id" type="java.lang.Integer"> <column name="id" /> <generator class="identity" /> </id> <property name="firstName" type="string"> <column name="first_name" length="20" /> </property> <property name="lastName" type="string"> <column name="last_name" length="20" /> </property> <property name="salary" type="java.lang.Integer"> <column name="salary" /> </property> </class> </hibernate-mapping>
5. Create hibernate configuration file
File: hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-configuration SYSTEM "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.dialect"> org.hibernate.dialect.MySQLDialect </property> <property name="hibernate.connection.driver_class"> com.mysql.jdbc.Driver </property> <!-- Database information --> <property name="hibernate.connection.url"> jdbc:mysql://localhost/testdb </property> <property name="hibernate.connection.username"> root </property> <property name="hibernate.connection.password"> 1234567890 </property> <!-- List mapping XML files --> <mapping resource="Employee.hbm.xml" /> </session-factory> </hibernate-configuration>
6. Create application class
Finally, we will create the application class to run by the main() method. There are some methods to perform CRUD operations (create, retrive, update, delete).
File: ManageEmployee.java
package com.realtut; import java.util.Iterator; import java.util.List; import org.hibernate.HibernateException; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import com.realtut.entity.Employee; public class ManageEmployee { private static SessionFactory factory; public static void main(String[] args) { try { factory = new Configuration().configure().buildSessionFactory(); } catch (Throwable ex) { ex.printStackTrace(); } ManageEmployee manageEmployee = new ManageEmployee(); // Add few employee records in database Integer empID1 = manageEmployee.addEmployee("David", "Bishop", 1000); Integer empID2 = manageEmployee.addEmployee("Chris", "Ali", 5000); Integer empID3 = manageEmployee.addEmployee("John", "Vector", 10000); // List down all the employees System.out.println("List down all the employees:"); manageEmployee.listEmployees(); // Update employee's records manageEmployee.updateEmployee(empID1, 5000); // Delete an employee from the database manageEmployee.deleteEmployee(empID2); // List down new list of the employees System.out.println("List down new list of the employees:"); manageEmployee.listEmployees(); } // Method to CREATE an employee in the database public Integer addEmployee(String fname, String lname, int salary) { Session session = factory.openSession(); Transaction tx = null; Integer employeeID = null; try { tx = session.beginTransaction(); Employee employee = new Employee(fname, lname, salary); employeeID = (Integer) session.save(employee); tx.commit(); } catch (HibernateException e) { if (tx != null) tx.rollback(); e.printStackTrace(); } finally { session.close(); } return employeeID; } // Method to READ all the employees public void listEmployees() { Session session = factory.openSession(); Transaction tx = null; try { tx = session.beginTransaction(); List employees = session.createQuery("FROM Employee").list(); for (Iterator iterator = employees.iterator(); iterator.hasNext();) { Employee employee = (Employee) iterator.next(); System.out.print("First Name: " + employee.getFirstName()); System.out.print(" Last Name: " + employee.getLastName()); System.out.println(" Salary: " + employee.getSalary()); } tx.commit(); } catch (HibernateException e) { if (tx != null) tx.rollback(); e.printStackTrace(); } finally { session.close(); } } // Method to UPDATE salary for an employee public void updateEmployee(Integer EmployeeID, int salary) { Session session = factory.openSession(); Transaction tx = null; try { tx = session.beginTransaction(); Employee employee = (Employee) session.get(Employee.class, EmployeeID); employee.setSalary(salary); session.update(employee); tx.commit(); } catch (HibernateException e) { if (tx != null) tx.rollback(); e.printStackTrace(); } finally { session.close(); } } // Method to DELETE an employee from the records public void deleteEmployee(Integer EmployeeID) { Session session = factory.openSession(); Transaction tx = null; try { tx = session.beginTransaction(); Employee employee = (Employee) session.get(Employee.class, EmployeeID); session.delete(employee); tx.commit(); } catch (HibernateException e) { if (tx != null) tx.rollback(); e.printStackTrace(); } finally { session.close(); } } }
Output:
List down all the employees: First Name: David Last Name: Bishop Salary: 1000 First Name: Chris Last Name: Ali Salary: 5000 First Name: John Last Name: Vector Salary: 10000 List down new list of the employees: First Name: David Last Name: Bishop Salary: 5000 First Name: John Last Name: Vector Salary: 10000