J2ME Java Tutorial

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
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.RecordEnumeration;
import javax.microedition.rms.RecordFilter;
import javax.microedition.rms.RecordStore;
public class J2MESearchMixedRecordDataTypeExample extends MIDlet implements CommandListener {
  private Display display;
  private Alert alert;
  private Form form = new Form("Mixed RecordEnumeration");
  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 Filter filter = null;
  public J2MESearchMixedRecordDataTypeExample() {
    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);
        byte[] outputRecord;
        String outputString[] = { "A", "B", "M" };
        int outputInteger[] = { 15, 10, 5 };
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        DataOutputStream outputDataStream = new DataOutputStream(outputStream);
        for (int x = 0; x < 3; x++) {
          outputDataStream.writeUTF(outputString[x]);
          outputDataStream.writeInt(outputInteger[x]);
          outputDataStream.flush();
          outputRecord = outputStream.toByteArray();
          recordstore.addRecord(outputRecord, 0, outputRecord.length);
          outputStream.reset();
        }
        outputStream.close();
        outputDataStream.close();
        String inputString;
        byte[] byteInputData = new byte[300];
        ByteArrayInputStream inputStream = new ByteArrayInputStream(byteInputData);
        DataInputStream inputDataStream = new DataInputStream(inputStream);
        if (recordstore.getNumRecords() > 0) {
          filter = new Filter("Mary");
          recordEnumeration = recordstore.enumerateRecords(filter, null, false);
          while (recordEnumeration.hasNextElement()) {
            recordstore.getRecord(recordEnumeration.nextRecordId(), byteInputData, 0);
            inputString = inputDataStream.readUTF() + " " + inputDataStream.readInt();
            alert = new Alert("Reading", inputString, null, AlertType.WARNING);
            alert.setTimeout(Alert.FOREVER);
            display.setCurrent(alert);
          }
        }
        inputStream.close();
        recordstore.closeRecordStore();
        if (RecordStore.listRecordStores() != null) {
          RecordStore.deleteRecordStore("myRecordStore");
          filter.filterClose();
          recordEnumeration.destroy();
        }
      } 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 searchcriteria) {
    search = searchcriteria;
  }
  public boolean matches(byte[] suspect) {
    String string = null;
    try {
      inputstream = new ByteArrayInputStream(suspect);
      datainputstream = new DataInputStream(inputstream);
      string = datainputstream.readUTF();
    } catch (Exception error) {
      return false;
    }
    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) {
    }
  }
}