populatemusictable.java

来自「servletjsp一些应用程序」· Java 代码 · 共 55 行

package coreservlets.jdo;

import java.util.*;
import java.io.*;
import javax.jdo.*;

/** Populate database with music records by using JDO.
 *  <P>
 *  Taken from Core Servlets and JavaServer Pages 2nd Edition
 *  from Prentice Hall and Sun Microsystems Press,
 *  http://www.coreservlets.com/.
 *  &copy; 2003 Marty Hall and Larry Brown.
 *  May be freely used or adapted. 
 */
 
public class PopulateMusicTable {
  public static void main(String[] args) {
    // Create seven new music objects to place in the database.
    Music[] objects = {
      new Music(1, "Mozart", "No. 21 in C# minor", 7, 24.99F),
      new Music(2, "Beethoven", "No. 3 in C minor", 28, 10.99F),
      new Music(3, "Beethoven", "No. 5 Eb major", 33, 10.99F),
      new Music(4, "Rachmaninov", "No. 2 in C minor", 9, 18.99F),
      new Music(5, "Mozart", "No. 24 in C minor", 11, 21.99F),
      new Music(6, "Beethoven", "No. 4 in G", 33, 12.99F),
      new Music(7, "Liszt", "No. 1 in Eb major", 48, 10.99F)
    };
    
    // Load properties file with JDO information. The properties
    // file contains ORM Framework information specific to the 
    // vendor and information for connecting to the database.
    Properties properties = new Properties();
    try {
      FileInputStream fis =
        new FileInputStream("jdo.properties");
      properties.load(fis);
    } catch(IOException ioe) {
      System.err.println("Problem loading properties file: " +
                         ioe);
      return;
    }

    // Initialize manager for persistence framework.
    PersistenceManagerFactory pmf =
      JDOHelper.getPersistenceManagerFactory(properties);
    PersistenceManager pm = pmf.getPersistenceManager();

    // Write the new Music objects to the database.
    Transaction transaction = pm.currentTransaction();
    transaction.begin();
    pm.makePersistentAll(objects);
    transaction.commit();
    pm.close ();
  }
}