Mark Abstract Entity With Mapped Superclass : Clob Blob « JPA « Java Tutorial

1. Java Tutorial
2. JPA
3. Clob Blob

File: Employee.java

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.DiscriminatorColumn;
import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.MappedSuperclass;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;

@Entity
@Table(name = "EMP")
@Inheritance
@DiscriminatorColumn(name = "EMP_TYPE")
public abstract class Employee {
  @Id
  private int id;

  private String name;

  @Temporal(TemporalType.DATE)
  @Column(name = "S_DATE")
  private Date startDate;

  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 Date getStartDate() {
    return startDate;
  }

  public void setStartDate(Date startDate) {
    this.startDate = startDate;
  }

  public String toString() {
    return "Employee id: " + getId() + " name: " + getName();
  }
}

@MappedSuperclass
abstract class AbstractEmployee extends Employee {
  private int vacation;

  public int getVacation() {
    return vacation;
  }

  public void setVacation(int vacation) {
    this.vacation = vacation;
  }
}

@Entity
@DiscriminatorValue("FTEmp")
class FullTimeEmployee extends AbstractEmployee {
  private long salary;

  private long pension;

  public long getPension() {
    return pension;
  }

  public void setPension(long pension) {
    this.pension = pension;
  }

  public long getSalary() {
    return salary;
  }

  public void setSalary(long salary) {
    this.salary = salary;
  }

  public String toString() {
    return "FullTimeEmployee id: " + getId() + " name: " + getName();
  }
}

@Entity(name = "PTEmp")
@DiscriminatorValue("PTEmp")
class PartTimeEmployee extends AbstractEmployee {
  @Column(name = "H_RATE")
  private float hourlyRate;

  public float getHourlyRate() {
    return hourlyRate;
  }

  public void setHourlyRate(float hourlyRate) {
    this.hourlyRate = hourlyRate;
  }

  public String toString() {
    return "PartTimeEmployee id: " + getId() + " name: " + getName();
  }
}

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 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();

    PartTimeEmployee emp = new PartTimeEmployee();
    emp.setId(1);
    emp.setName("Tom");
    emp.setStartDate(new java.util.Date());
    emp.setHourlyRate(12);
    em.persist(emp);
    
    FullTimeEmployee emp1 = new FullTimeEmployee();
    emp1.setId(2);
    emp1.setName("Tom");
    emp1.setStartDate(new java.util.Date());
    emp1.setSalary(123);
    
    em.persist(emp1);


    em.getTransaction().commit();
    em.close();
    emf.close();

    Helper.checkData();
  }
}

File: persistence.xml

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/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>

22.24.Clob Blob
	22.24.1.	Mark String As Lob
	22.24.2.	Mark Byte Array Field As Lob
	22.24.3.	Mark Abstract Entity With Mapped Superclass
	22.24.4.	Map Serializable Entity To Lob
	22.24.5.	Java Byte Array Lob Mapped To Long VarBinary