Date Mapped To Timestamp By Default : Calendar Date « JPA « Java Tutorial

1. Java Tutorial
2. JPA
3. Calendar Date

File: Student.java

import java.util.Date;

import javax.persistence.Basic;
import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Student {
  @Id
  private long id = System.currentTimeMillis();

  @Basic
  private String name;

  @Basic
  private Date dateOfBirth = new Date();

  public Date getDateOfBirth() {
    return dateOfBirth;
  }

  public void setDateOfBirth(Date dateOfBirth) {
    this.dateOfBirth = dateOfBirth;
  }

  public long getId() {
    return id;
  }

  public void setId(long id) {
    this.id = id;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }
  
  
}

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 {
    EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAService");
    EntityManager em = emf.createEntityManager();
    em.getTransaction().begin();
    
    
    em.persist(new Student());
    em.flush();
    em.persist(new Student());
    em.flush();

    
    
    em.getTransaction().commit();
    Helper.checkData();
    em.close();
    emf.close();
  }
}

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.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>

22.23.Calendar Date
	22.23.1.	Mark Java Calendar With Temporal Type Date
	22.23.2.	Temporal Type TIMESTAMP
	22.23.3.	Temporal Type DATE
	22.23.4.	Map Java Date To Timestamp
	22.23.5.	Map Java Date To Time
	22.23.6.	Map Java Date To Date
	22.23.7.	Map Java Calendar To Timestamp
	22.23.8.	Java Calendar Mapped To Date
	22.23.9.	Date Mapped To Timestamp By Default