Search Example : Database Persistence « J2ME « Java






Search Example

Search Example
/*
J2ME: The Complete Reference

James Keogh

Publisher: McGraw-Hill

ISBN 0072227109

*/

// jad file (Please verify the jar size first)
/*
MIDlet-Name: SearchExample
MIDlet-Version: 1.0
MIDlet-Vendor: MyCompany
MIDlet-Jar-URL: SearchExample.jar
MIDlet-1: SearchExample, , SearchExample
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-1.0
MIDlet-JAR-SIZE: 100

*/
import javax.microedition.rms.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.*;

public class SearchExample extends MIDlet implements CommandListener
{
  private Display display;
  private Alert alert;
  private Form form; 
  private Command exit; 
  private Command start;
  private RecordStore recordstore = null;
  private RecordEnumeration recordEnumeration = null;
  private Filter filter = null;
  public SearchExample ()
  {
    display = Display.getDisplay(this);
    exit = new Command("Exit", Command.SCREEN, 1);
    start = new Command("Start", Command.SCREEN, 1);
    form = new Form("Mixed RecordEnumeration", null);
    form.addCommand(exit);
    form.addCommand(start);
    form.setCommandListener(this);
  }
  public void startApp()
  {
    display.setCurrent(form);
  }
  public void pauseApp()
  {
  }
  public void destroyApp( boolean unconditional )
  {
  }
  public void commandAction(Command command, Displayable displayable)
  {
    if (command == exit)
    {
      destroyApp(true);
      notifyDestroyed();
    }
    else if (command == start)
    {
      try
      {
        recordstore = RecordStore.openRecordStore(
                          "myRecordStore", true );
      }
      catch (Exception error)
      {
        alert = new Alert("Error Creating", 
                 error.toString(), null, AlertType.WARNING); 
        alert.setTimeout(Alert.FOREVER); 
        display.setCurrent(alert);
      }
      try
      {
        String outputData[] = {"Mary", "Bob", "Adam"};
        for (int x = 0 ; x < 3; x++)
        {
          byte[] byteOutputData = outputData[x].getBytes();
          recordstore.addRecord(byteOutputData, 0, 
                         byteOutputData.length);
        }
      }
      catch ( Exception error)
      {
        alert = new Alert("Error Writing", 
               error.toString(), null, AlertType.WARNING); 
        alert.setTimeout(Alert.FOREVER); 
        display.setCurrent(alert);
      }
      try
      {
        filter = new Filter("Bob");
        recordEnumeration = recordstore.enumerateRecords(
                     filter, null, false);
        if (recordEnumeration.numRecords() > 0)
        {
          String string = new String(recordEnumeration.nextRecord());
          alert = new Alert("Reading", string, 
                     null, AlertType.WARNING);
          alert.setTimeout(Alert.FOREVER); 
          display.setCurrent(alert); 
        }
      }
      catch (Exception error)
      {
       alert = new Alert("Error Reading", 
                error.toString(), null, AlertType.WARNING); 
       alert.setTimeout(Alert.FOREVER); 
       display.setCurrent(alert);
      }
      try
      {
       recordstore.closeRecordStore();
      }
      catch (Exception error)
      {
        alert = new Alert("Error Closing", 
                error.toString(), null, AlertType.WARNING); 
        alert.setTimeout(Alert.FOREVER); 
        display.setCurrent(alert);
      }
      if (RecordStore.listRecordStores() != null)
      {
        try
        {
         RecordStore.deleteRecordStore("myRecordStore");
         recordEnumeration.destroy();
         filter.filterClose();
        }
        catch (Exception error)
        {
         alert = new Alert("Error Removing", 
                  error.toString(), null, AlertType.WARNING); 
         alert.setTimeout(Alert.FOREVER); 
         display.setCurrent(alert);
        }
      }
    }
  }     
}
class Filter implements RecordFilter
{
  private String search = null;
  private ByteArrayInputStream inputstream = null;
  private DataInputStream datainputstream = null;
  public Filter(String search)
  {
    this.search = search.toLowerCase();
  }
  public boolean matches(byte[] suspect)
  {
    String string = new String(suspect).toLowerCase();
    if (string!= null && string.indexOf(search) != -1)
      return true;
    else
      return false;
  }
  public void filterClose()
  {
    try
    {
      if (inputstream != null)
      {
        inputstream.close();
      }
      if (datainputstream != null)
      {
        datainputstream.close();
      }
    }
    catch ( Exception error)
    {
    }
  }
}

           
       








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