Java by API/javax.persistence/Embedded
javax.persistence.Embedded
<source lang="java">
File: Address.java
import javax.persistence.Column; import javax.persistence.Embeddable; @Embeddable public class Address {
private String street; private String city; private String state; @Column(name="ZIP_CODE") private String zip; public String getStreet() { return street; } public void setStreet(String address) { this.street = address; } public String getCity() { return city; } public void setCity(String city) { this.city = city; } public String getState() { return state; } public void setState(String state) { this.state = state; } public String getZip() { return zip; } public void setZip(String zip) { this.zip = zip; } public String toString() { return "Address street: " + getStreet() + ", city: " + getCity() + ", state: " + getState() + ", zip: " + getZip(); }
}
File: Company.java
import javax.persistence.Embedded; import javax.persistence.Entity; import javax.persistence.Id; @Entity public class Company {
@Id private String name; @Embedded private Address address; public String getName() { return name; } public void setName(String name) { this.name = name; } public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } public String toString() { return "Company name: " + getName() + " at " + getAddress(); }
}
File: Professor.java
import javax.persistence.Embedded; import javax.persistence.Entity; import javax.persistence.Id; @Entity public class Professor {
@Id private int id; private String name; private long salary; @Embedded private Address address; 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 Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } public String toString() { return "Professor id: " + getId() + " name: " + getName() + " with " + getAddress(); }
}
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 createProfessorAndAddress(int id, String name, long salary, String street, String city, String state, String zip) { Professor emp = new Professor(); emp.setId(id); emp.setName(name); emp.setSalary(salary); Address addr = new Address(); addr.setStreet(street); addr.setCity(city); addr.setState(state); addr.setZip(zip); emp.setAddress(addr); em.persist(emp); return emp; } public Company createCompanyAndAddress(String name, String street, String city, String state, String zip) { Company c = new Company(); c.setName(name); Address addr = new Address(); addr.setStreet(street); addr.setCity(city); addr.setState(state); addr.setZip(zip); c.setAddress(addr); em.persist(c); return c; } public Collection<Professor> findAllProfessors() { Query query = em.createQuery("SELECT e FROM Professor e"); return (Collection<Professor>) query.getResultList(); } public Collection<Company> findAllCompanies() { Query query = em.createQuery("SELECT e FROM Company e"); return (Collection<Company>) 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 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.createProfessorAndAddress(1, "name", 100, "street", "city", "state", "zip"); service.createCompanyAndAddress("Name", "Street", "City", "State", "Zip"); System.out.println("Professors and Addresses:"); for (Professor emp : service.findAllProfessors()) { System.out.println(emp); } for (Company c : service.findAllCompanies()) { System.out.println(c); } util.checkData("select * from Professor"); util.checkData("select * from Company"); 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>