Java/JPA/One to Many Mapping — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Текущая версия на 10:22, 1 июня 2010
Содержание
- 1 One To Many based on List Collection
- 2 One To Many Bidirectional Mapping
- 3 One To Many MappedBy
- 4 One To Many Mapping with generated primary key
- 5 One To Many Mapping With MappedBy: To remove Mapping Table
- 6 One To Many Target Entity
- 7 One To Many Unidirectional Mapping
- 8 Query for One To Many Mapping
- 9 Use Collection In One To Many Mapping
One To Many based on List Collection
<source lang="java">
File: Department.java
import java.util.ArrayList; import java.util.Collection; import java.util.List; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.OrderBy; @Entity public class Department {
@Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int id; private String name; @OneToMany(mappedBy = "department") @OrderBy("name ASC") private List<Professor> employees; public Department() { employees = new ArrayList<Professor>(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public void addProfessor(Professor employee) { if (!getProfessors().contains(employee)) { getProfessors().add(employee); if (employee.getDepartment() != null) { employee.getDepartment().getProfessors().remove(employee); } employee.setDepartment(this); } } public Collection<Professor> getProfessors() { return employees; } public String toString() { return "Department id: " + getId() + ", name: " + getName(); }
}
File: Professor.java
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Professor {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; private long salary; @ManyToOne private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public long getSalary() { return salary; } public void setSalary(long salary) { this.salary = salary; } public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getDepartment(); }
}
File: ProfessorService.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.Query; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public Department createDepartment(String name) { Department dept = new Department(); dept.setName(name); em.persist(dept); return dept;
} public Collection<Department> findAllDepartments() {
Query query = em.createQuery("SELECT d FROM Department d"); return (Collection<Department>) query.getResultList();
} public Professor createProfessor(String name, long salary) {
Professor emp = new Professor(); emp.setName(name); emp.setSalary(salary); em.persist(emp); return emp;
} public Professor setProfessorDepartment(int empId, int deptId) {
Professor emp = em.find(Professor.class, empId); Department dept = em.find(Department.class, deptId); dept.addProfessor(emp); return emp;
} public Collection<Professor> findAllProfessors() {
Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList();
} }
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); Professor emp = service.createProfessor("empName", 100L); Department dept = service.createDepartment("deptName"); emp = service.setProfessorDepartment(emp.getId(),dept.getId()); System.out.println(emp.getDepartment() + " with Professors:"); System.out.println(emp.getDepartment().getProfessors()); Collection<Professor> emps = service.findAllProfessors(); if (emps.isEmpty()) { System.out.println("No Professors found "); } else { System.out.println("Found Professors:"); for (Professor emp1 : emps) { System.out.println(emp1); } } Collection<Department> depts = service.findAllDepartments(); if (depts.isEmpty()) { System.out.println("No Departments found "); } else { System.out.println("Found Departments:"); for (Department dept1 : depts) { System.out.println(dept1 + " with " + dept1.getProfessors().size() + " employees " + dept1.getProfessors()); } } util.checkData("select * from Professor"); util.checkData("select * from Department"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
One To Many Bidirectional Mapping
<source lang="java">
File: Department.java
import java.util.ArrayList; import java.util.Collection; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; @Entity public class Department {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @OneToMany(mappedBy="department") private Collection<Professor> employees; public Department() { employees = new ArrayList<Professor>(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public void addProfessor(Professor employee) { if (!getProfessors().contains(employee)) { getProfessors().add(employee); if (employee.getDepartment() != null) { employee.getDepartment().getProfessors().remove(employee); } employee.setDepartment(this); } } public Collection<Professor> getProfessors() { return employees; } public String toString() { return "Department id: " + getId() + ", name: " + getName(); }
}
File: Professor.java
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Professor {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; private long salary; @ManyToOne private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public long getSalary() { return salary; } public void setSalary(long salary) { this.salary = salary; } public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getDepartment(); }
}
File: ProfessorService.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.Query; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public Department createDepartment(String name) { Department dept = new Department(); dept.setName(name); em.persist(dept); return dept; } public Collection<Department> findAllDepartments() { Query query = em.createQuery("SELECT d FROM Department d"); return (Collection<Department>) query.getResultList(); } public Professor createProfessor(String name, long salary) { Professor emp = new Professor(); emp.setName(name); emp.setSalary(salary); em.persist(emp); return emp; } public Professor setProfessorDepartment(int empId, int deptId) { Professor emp = em.find(Professor.class, empId); Department dept = em.find(Department.class, deptId); dept.addProfessor(emp); return emp; } public Collection<Professor> findAllProfessors() { Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList(); }
}
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); Professor emp = service.createProfessor("empName",100); Department dept = service.createDepartment("deptName"); emp = service.setProfessorDepartment(emp.getId(),dept.getId()); System.out.println(emp.getDepartment() + " with Professors:"); System.out.println(emp.getDepartment().getProfessors()); Collection<Professor> emps = service.findAllProfessors(); if (emps.isEmpty()) { System.out.println("No Professors found "); } else { System.out.println("Found Professors:"); for (Professor emp1 : emps) { System.out.println(emp1); } } Collection<Department> depts = service.findAllDepartments(); if (depts.isEmpty()) { System.out.println("No Departments found "); } else { System.out.println("Found Departments:"); for (Department dept1 : depts) { System.out.println(dept1 + " with " + dept1.getProfessors().size() + " employees"); } }
util.checkData("select * from Professor"); util.checkData("select * from Department"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
One To Many MappedBy
<source lang="java">
File: Department.java
import java.util.ArrayList; import java.util.Collection; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; @Entity public class Department {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @OneToMany(mappedBy="department") private Collection<Professor> employees; public Department() { employees = new ArrayList<Professor>(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public void addProfessor(Professor employee) { if (!getProfessors().contains(employee)) { getProfessors().add(employee); if (employee.getDepartment() != null) { employee.getDepartment().getProfessors().remove(employee); } employee.setDepartment(this); } } public Collection<Professor> getProfessors() { return employees; } public String toString() { return "Department id: " + getId() + ", name: " + getName(); }
}
File: Professor.java
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Professor {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; private long salary; @ManyToOne private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public long getSalary() { return salary; } public void setSalary(long salary) { this.salary = salary; } public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getDepartment(); }
}
File: ProfessorService.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.Query; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public Department createDepartment(String name) { Department dept = new Department(); dept.setName(name); em.persist(dept); return dept; } public Collection<Department> findAllDepartments() { Query query = em.createQuery("SELECT d FROM Department d"); return (Collection<Department>) query.getResultList(); } public Professor createProfessor(String name, long salary) { Professor emp = new Professor(); emp.setName(name); emp.setSalary(salary); em.persist(emp); return emp; } public Professor setProfessorDepartment(int empId, int deptId) { Professor emp = em.find(Professor.class, empId); Department dept = em.find(Department.class, deptId); dept.addProfessor(emp); return emp; } public Collection<Professor> findAllProfessors() { Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList(); }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); Professor emp = service.createProfessor("empName",100); Department dept = service.createDepartment("deptName"); emp = service.setProfessorDepartment(emp.getId(),dept.getId()); System.out.println(emp.getDepartment() + " with Professors:"); System.out.println(emp.getDepartment().getProfessors()); Collection<Professor> emps = service.findAllProfessors(); if (emps.isEmpty()) { System.out.println("No Professors found "); } else { System.out.println("Found Professors:"); for (Professor emp1 : emps) { System.out.println(emp1); } } Collection<Department> depts = service.findAllDepartments(); if (depts.isEmpty()) { System.out.println("No Departments found "); } else { System.out.println("Found Departments:"); for (Department dept1 : depts) { System.out.println(dept1 + " with " + dept1.getProfessors().size() + " employees"); } }
util.checkData("select * from Professor"); util.checkData("select * from Department"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
One To Many Mapping with generated primary key
<source lang="java">
File: Department.java
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; @Entity public class Department {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public String toString() { return "Department id: " + getId() + ", name: " + getName(); }
}
File: Professor.java
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Professor {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; private long salary; @ManyToOne private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public long getSalary() { return salary; } public void setSalary(long salary) { this.salary = salary; } public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getDepartment(); }
}
File: ProfessorService.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.Query; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public Professor createProfessor(String name, long salary) { Professor emp = new Professor(); emp.setName(name); emp.setSalary(salary); em.persist(emp); return emp; } public Professor setProfessorDepartment(int empId, int deptId) { Professor emp = em.find(Professor.class, empId); Department dept = em.find(Department.class, deptId); emp.setDepartment(dept); return emp; } public Collection<Professor> findAllProfessors() { Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList(); } public Department createDepartment(String name) { Department dept = new Department(); dept.setName(name); em.persist(dept); return dept; } public Collection<Department> findAllDepartments() { Query query = em.createQuery("SELECT d FROM Department d"); return (Collection<Department>) query.getResultList(); }
}
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); Professor emp = service.createProfessor("empName", 100); Department dept = service.createDepartment("deptName"); Collection<Professor> emps = service.findAllProfessors(); for (Professor emp1 : emps) { System.out.println(emp1); } Collection<Department> depts = service.findAllDepartments(); for (Department dept1 : depts) { System.out.println(dept1); } util.checkData("select * from Professor"); util.checkData("select * from Department"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
One To Many Mapping With MappedBy: To remove Mapping Table
<source lang="java">
File: Student.java import javax.persistence.CascadeType; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Student {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @ManyToOne (cascade=CascadeType.ALL) private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; }
public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "\n\nID:" + id + "\nName:" + name + "\n\n" + department; }
}
File: Department.java
import java.util.Set; import javax.persistence.CascadeType; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; @Entity public class Department {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @OneToMany(mappedBy="department",cascade=CascadeType.ALL) private Set<Student> students; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public Set<Student> getStudents() { return students; } public void setStudent(Set<Student> students) { this.students = students; } public String toString() { return "Department id: " + getId() + ", name: " + getName()+"Student:"+ students; }
}
File: Main.java import java.util.List; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; import javax.persistence.Query; public class Main {
static EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAService"); static EntityManager em = emf.createEntityManager(); public static void main(String[] a) throws Exception { em.getTransaction().begin(); Student student = new Student(); student.setName("Joe"); em.persist(student); Student student1 = new Student(); student1.setName("Joe"); em.persist(student1); Department dept = new Department(); dept.setName("dept name"); student.setDepartment(dept); student1.setDepartment(dept); em.flush();
Query query = em.createQuery("SELECT e FROM Student e"); List<Student> list = (List<Student>) query.getResultList(); System.out.println(list.get(0).getDepartment()); query = em.createQuery("SELECT d FROM Department d"); List<Department> dList = (List<Department>) query.getResultList(); System.out.println(dList.get(0).getStudents()); em.getTransaction().rumit(); em.close(); emf.close(); Helper.checkData(); }
}
File: Helper.java import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Helper {
public static void checkData() throws Exception { Class.forName("org.hsqldb.jdbcDriver"); Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial", "sa", ""); Statement st = conn.createStatement(); ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" }); while (mrs.next()) { String tableName = mrs.getString(3); System.out.println("\n\n\n\nTable Name: "+ tableName); ResultSet rs = st.executeQuery("select * from " + tableName); ResultSetMetaData metadata = rs.getMetaData(); while (rs.next()) { System.out.println(" Row:"); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.println(" Column Name: "+ metadata.getColumnLabel(i + 1)+ ", "); System.out.println(" Column Type: "+ metadata.getColumnTypeName(i + 1)+ ": "); Object value = rs.getObject(i + 1); System.out.println(" Column Value: "+value+"\n"); } } } }
}
File: persistence.xml <persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
One To Many Target Entity
<source lang="java">
File: Department.java
import java.util.ArrayList; import java.util.Collection; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; @Entity public class Department {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @OneToMany(targetEntity=Professor.class, mappedBy="department") private Collection employees; public Department() { employees = new ArrayList<Professor>(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public void addProfessor(Professor employee) { if (!getProfessors().contains(employee)) { getProfessors().add(employee); if (employee.getDepartment() != null) { employee.getDepartment().getProfessors().remove(employee); } employee.setDepartment(this); } } public Collection getProfessors() { return employees; } public String toString() { return "Department id: " + getId() + ", name: " + getName(); }
}
File: Professor.java
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Professor {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; private long salary; @ManyToOne private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public long getSalary() { return salary; } public void setSalary(long salary) { this.salary = salary; } public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getDepartment(); }
}
File: ProfessorService.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.Query; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public Department createDepartment(String name) { Department dept = new Department(); dept.setName(name); em.persist(dept); return dept; } public Collection<Department> findAllDepartments() { Query query = em.createQuery("SELECT d FROM Department d"); return (Collection<Department>) query.getResultList(); } public Professor createProfessor(String name, long salary) { Professor emp = new Professor(); emp.setName(name); emp.setSalary(salary); em.persist(emp); return emp; } public Professor setProfessorDepartment(int empId, int deptId) { Professor emp = em.find(Professor.class, empId); Department dept = em.find(Department.class, deptId); dept.addProfessor(emp); return emp; } public Collection<Professor> findAllProfessors() { Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList(); }
}
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); Professor emp = service.createProfessor("empName",100); Department dept = service.createDepartment("deptName"); emp = service.setProfessorDepartment(emp.getId(),dept.getId()); System.out.println(emp.getDepartment() + " with Professors:"); System.out.println(emp.getDepartment().getProfessors()); Collection<Professor> emps = service.findAllProfessors(); if (emps.isEmpty()) { System.out.println("No Professors found "); } else { System.out.println("Found Professors:"); for (Professor emp1 : emps) { System.out.println(emp1); } } Collection<Department> depts = service.findAllDepartments(); if (depts.isEmpty()) { System.out.println("No Departments found "); } else { System.out.println("Found Departments:"); for (Department dept1 : depts) { System.out.println(dept1 + " with " + dept1.getProfessors().size() + " employees"); } }
util.checkData("select * from Professor"); util.checkData("select * from Department"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
One To Many Unidirectional Mapping
<source lang="java">
File: Phone.java
import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; @Entity public class Phone {
@Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int id; @Column(name = "NUM") private String number; private String type; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getNumber() { return number; } public void setNumber(String phoneNo) { this.number = phoneNo; } public String getType() { return type; } public void setType(String phoneType) { this.type = phoneType; } public String toString() { return "Phone id: " + getId() + ", no: " + getNumber() + ", type: " + getType(); }
}
File: Professor.java
import java.util.ArrayList; import java.util.Collection; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.OneToMany; @Entity public class Professor {
@Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int id; private String name; private long salary; @OneToMany @JoinTable(name = "EMP_PHONE", joinColumns = @JoinColumn(name = "EMP_ID"), inverseJoinColumns = @JoinColumn(name = "PHONE_ID")) private Collection<Phone> phones; public Professor() { phones = new ArrayList<Phone>(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public long getSalary() { return salary; } public void setSalary(long salary) { this.salary = salary; } public void addPhone(Phone phone) { if (!getPhones().contains(phone)) { getPhones().add(phone); } } public Collection<Phone> getPhones() { return phones; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getPhones().size() + " phones"; }
}
File: ProfessorService.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.Query; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public Professor createProfessor(String name, long salary) { Professor emp = new Professor(); emp.setName(name); emp.setSalary(salary); em.persist(emp); return emp; } public Professor addProfessorPhone(int empId, int phoneId) { Professor emp = em.find(Professor.class, empId); Phone phone = em.find(Phone.class, phoneId); emp.addPhone(phone); return emp; } public Collection<Professor> findAllProfessors() { Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList(); } public Phone createPhone(String num, String type) { Phone phone = new Phone(); phone.setNumber(num); phone.setType(type); em.persist(phone); return phone; } public Collection<Phone> findAllPhones() { Query query = em.createQuery("SELECT p FROM Phone p"); return (Collection<Phone>) query.getResultList(); }
}
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); Professor emp = service.createProfessor("empName",100); Phone phone = service.createPhone("1111111111","phoneType"); emp = service.addProfessorPhone(emp.getId(),phone.getId()); Collection<Professor> emps = service.findAllProfessors(); if (emps.isEmpty()) { System.out.println("No Professors found "); } else { System.out.println("Found Professors:"); for (Professor emp1 : emps) { System.out.println(emp1); } } Collection<Phone> phones = service.findAllPhones(); if (phones.isEmpty()) { System.out.println("No Phones found "); } else { System.out.println("Found Phones:"); for (Phone phone1 : phones) { System.out.println(phone1); } }
util.checkData("select * from Professor"); util.checkData("select * from Phone"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
Query for One To Many Mapping
<source lang="java">
File: Department.java
import java.util.ArrayList; import java.util.Collection; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.OneToMany; @Entity public class Department {
@Id private int id; private String name; @OneToMany(mappedBy="department") private Collection<Professor> employees; public Department() { employees = new ArrayList<Professor>(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Collection<Professor> getProfessors() { return employees; } public String toString() { return "Department no: " + getId() + ", name: " + getName(); }
}
File: Professor.java
import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Professor {
@Id private int id; private String name; private long salary; @ManyToOne private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; }
public long getSalary() { return salary; } public Department getDepartment() { return department; } public void setDepartment(Department dept) { this.department = dept; } public String toString() { return "Professor " + getId() + ": name: " + getName() + ", salary: " + getSalary(); }
}
File: ProfessorService.java import java.util.List; import javax.persistence.EntityManager; public class ProfessorService {
protected EntityManager em; public ProfessorService(EntityManager em) { this.em = em; } public List findAll() { return em.createQuery("SELECT e FROM Professor e").getResultList(); }
}
File: JPAUtil.java import java.io.Reader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class JPAUtil {
Statement st; public JPAUtil() throws Exception{ Class.forName("org.hsqldb.jdbcDriver"); System.out.println("Driver Loaded."); String url = "jdbc:hsqldb:data/tutorial"; Connection conn = DriverManager.getConnection(url, "sa", ""); System.out.println("Got Connection."); st = conn.createStatement(); } public void executeSQLCommand(String sql) throws Exception { st.executeUpdate(sql); } public void checkData(String sql) throws Exception { ResultSet rs = st.executeQuery(sql); ResultSetMetaData metadata = rs.getMetaData(); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.print("\t"+ metadata.getColumnLabel(i + 1)); } System.out.println("\n----------------------------------"); while (rs.next()) { for (int i = 0; i < metadata.getColumnCount(); i++) { Object value = rs.getObject(i + 1); if (value == null) { System.out.print("\t "); } else { System.out.print("\t"+value.toString().trim()); } } System.out.println(""); } }
}
File: Main.java import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public class Main {
public static void main(String[] a) throws Exception { JPAUtil util = new JPAUtil(); EntityManagerFactory emf = Persistence.createEntityManagerFactory("ProfessorService"); EntityManager em = emf.createEntityManager(); ProfessorService service = new ProfessorService(em); em.getTransaction().begin(); service.findAll(); util.checkData("select * from Professor"); util.checkData("select * from Department"); em.getTransaction().rumit(); em.close(); emf.close(); }
}
File: persistence.xml
<persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>
Use Collection In One To Many Mapping
<source lang="java">
File: Department.java
import java.util.Collection; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; @Entity public class Department {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @OneToMany(mappedBy="department") private Collection<Student> students; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String deptName) { this.name = deptName; } public Collection<Student> getStudents() { return students; } public void setStudent(Collection<Student> students) { this.students = students; } public String toString() { return "Department id: " + getId() + ", name: " + getName(); }
}
File: Student.java import javax.persistence.CascadeType; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.ManyToOne; @Entity public class Student {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; private String name; @ManyToOne (cascade=CascadeType.ALL) private Department department; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; }
public Department getDepartment() { return department; } public void setDepartment(Department department) { this.department = department; } public String toString() { return "\n\nID:" + id + "\nName:" + name + "\n\n" + department; }
}
File: Helper.java import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Helper {
public static void checkData() throws Exception { Class.forName("org.hsqldb.jdbcDriver"); Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial", "sa", ""); Statement st = conn.createStatement(); ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" }); while (mrs.next()) { String tableName = mrs.getString(3); System.out.println("\n\n\n\nTable Name: "+ tableName); ResultSet rs = st.executeQuery("select * from " + tableName); ResultSetMetaData metadata = rs.getMetaData(); while (rs.next()) { System.out.println(" Row:"); for (int i = 0; i < metadata.getColumnCount(); i++) { System.out.println(" Column Name: "+ metadata.getColumnLabel(i + 1)+ ", "); System.out.println(" Column Type: "+ metadata.getColumnTypeName(i + 1)+ ": "); Object value = rs.getObject(i + 1); System.out.println(" Column Value: "+value+"\n"); } } } }
}
File: Main.java import java.util.List; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; import javax.persistence.Query; public class Main {
static EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAService"); static EntityManager em = emf.createEntityManager(); public static void main(String[] a) throws Exception { em.getTransaction().begin(); Student student = new Student(); student.setName("Joe"); em.persist(student); Student student1 = new Student(); student1.setName("Joe"); em.persist(student1); Department dept = new Department(); dept.setName("dept name"); student.setDepartment(dept); student1.setDepartment(dept); em.flush();
Query query = em.createQuery("SELECT e FROM Student e"); List<Student> list = (List<Student>) query.getResultList(); System.out.println(list); query = em.createQuery("SELECT d FROM Department d"); List<Department> dList = (List<Department>) query.getResultList(); System.out.println(dList); em.getTransaction().rumit(); em.close(); emf.close(); Helper.checkData(); }
}
File: persistence.xml <persistence xmlns="http://java.sun.ru/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.ru/xml/ns/persistence http://java.sun.ru/xml/ns/persistence/persistence" version="1.0"> <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL"> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/> <property name="hibernate.hbm2ddl.auto" value="update"/> <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/> <property name="hibernate.connection.username" value="sa"/> <property name="hibernate.connection.password" value=""/> <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/> </properties> </persistence-unit>
</persistence>
</source>