File: Customer.java
import java.io.Serializable;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.DiscriminatorColumn;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import javax.persistence.JoinColumn;
import javax.persistence.MappedSuperclass;
import javax.persistence.OneToOne;
import javax.persistence.Table;
import javax.persistence.Version;
@Entity
@Table(name = "ADDRESS")
class Address implements Serializable {
protected String city;
@Id
protected Long id;
@Version
protected Long version;
@Column(name = "ZIP_CODE")
protected Long zipCode;
public Address() {
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public void setId(Long id) {
this.id = id;
}
public Long getId() {
return id;
}
public Long getZipCode() {
return zipCode;
}
public void setZipCode(Long zipCode) {
this.zipCode = zipCode;
}
}
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "TYPE")
class Employee extends Person implements Serializable {
protected String email;
protected String dept;
public Employee() {
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getDept() {
return dept;
}
public void setDept(String dept) {
this.dept = dept;
}
}
@MappedSuperclass
abstract class Person implements Serializable {
@OneToOne(cascade = { CascadeType.ALL })
@JoinColumn(name = "HOME_ADDRESS", referencedColumnName = "ID")
private Address homeAddress;
@Id
@Column(nullable = false)
@GeneratedValue(generator = "PersonIdGenerator")
private Long id;
@Version
private Long version;
public Person() {
}
public Address getHomeAddress() {
return homeAddress;
}
public void setHomeAddress(Address homeAddress) {
this.homeAddress = homeAddress;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
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();
Customer cus = new Customer();
cus.setFirstName("asdf");
em.persist(cus);
em.getTransaction().commit();
em.close();
emf.close();
Helper.checkData();
}
}
File: persistence.xml
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence" version="1.0">