implements RecordComparator : RecordComparator « javax.microedition.rms « Java by API





implements RecordComparator

 

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.midlet.MIDlet;
import javax.microedition.rms.RecordComparator;
import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordStore;

public class J2MESortExample extends MIDlet implements CommandListener {
  private Display display;

  private Alert alert;

  private Form form = new Form("Mixed RecordEnumeration", null);

  private Command exit = new Command("Exit", Command.SCREEN, 1);

  private Command start = new Command("Start", Command.SCREEN, 1);

  private RecordStore recordstore = null;

  private RecordEnumeration recordEnumeration = null;

  private Comparator comparator = null;

  public J2MESortExample() {
    display = Display.getDisplay(this);
    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);
        String outputData[] = { "M", "B", "A" };
        for (int x = 0; x < 3; x++) {
          byte[] byteOutputData = outputData[x].getBytes();
          recordstore.addRecord(byteOutputData, 0, byteOutputData.length);
        }
        StringBuffer buffer = new StringBuffer();
        Comparator comparator = new Comparator();
        recordEnumeration = recordstore.enumerateRecords(null, comparator, false);
        while (recordEnumeration.hasNextElement()) {
          buffer.append(new String(recordEnumeration.nextRecord()));
          buffer.append("\n");
        }
        alert = new Alert("Reading", buffer.toString(), null, AlertType.WARNING);
        alert.setTimeout(Alert.FOREVER);
        display.setCurrent(alert);
        recordstore.closeRecordStore();
        if (RecordStore.listRecordStores() != null) {
          RecordStore.deleteRecordStore("myRecordStore");
          recordEnumeration.destroy();
        }
      } catch (Exception error) {
        alert = new Alert("Error Removing", error.toString(), null, AlertType.WARNING);
        alert.setTimeout(Alert.FOREVER);
        display.setCurrent(alert);
      }
    }

  }
}

class Comparator implements RecordComparator {
  public int compare(byte[] record1, byte[] record2) {
    String string1 = new String(record1), string2 = new String(record2);
    int comparison = string1.compareTo(string2);
    if (comparison == 0)
      return RecordComparator.EQUIVALENT;
    else if (comparison < 0)
      return RecordComparator.PRECEDES;
    else
      return RecordComparator.FOLLOWS;
  }
}

   
  










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