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Write Read Example

/* J2ME: The Complete Reference James Keogh Publisher: McGraw-Hill ISBN 0072227109 */ //jad file (please verify the jar size) /* MIDlet-Name: WriteReadExample MIDlet-Version: 1.0 MIDlet-Vendor: MyCompany MIDlet-Jar-URL: WriteReadExample.jar MIDlet-1: WriteReadExample, , WriteReadExample 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 WriteReadExample extends MIDlet implements CommandListener {   private Display display;   private Alert alert;   private Form form;    private Command exit;    private Command start;   private RecordStore recordstore = null;   public WriteReadExample()   {     display = Display.getDisplay(this);     exit = new Command("Exit", Command.SCREEN, 1);     start = new Command("Start", Command.SCREEN, 1);     form = new Form("Record");     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 = "First Record";         byte[] byteOutputData = outputData.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       {         byte[] byteInputData = new byte[1];          int length = 0;         for (int x = 1; x <= recordstore.getNumRecords(); x++)         {           if (recordstore.getRecordSize(x) > byteInputData.length)           {             byteInputData = new byte[recordstore.getRecordSize(x)];           }           length = recordstore.getRecord(x, byteInputData, 0);         }           alert = new Alert("Reading", new String(byteInputData, 0,                            length), 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");         }         catch (Exception error)         {          alert = new Alert("Error Removing", error.toString(),                          null, AlertType.WARNING);           alert.setTimeout(Alert.FOREVER);           display.setCurrent(alert);         }       }           }   } }