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>