Friday, July 16, 2010

J2ME - Read and write using RMS

This is sample application to read and write record using RMS in J2ME mobie application


import javax.microedition.rms.*;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;

public class ReadWrite extends MIDlet
{
private RecordStore rs = null;
static final String REC_STORE = "db_1";

public ReadWrite()
{
openRecStore(); // Create the record store

// Write a few records and read them back
writeRecord("J2ME and MIDP");
writeRecord("Wireless Technology");
readRecords();

closeRecStore(); // Close record store
deleteRecStore(); // Remove the record store
}

public void destroyApp( boolean unconditional )
{
}

public void startApp()
{
// There is no user interface, go ahead and shutdown
destroyApp(false);
notifyDestroyed();
}

public void pauseApp()
{
}

public void openRecStore()
{
try
{
// The second parameter indicates that the record store
// should be created if it does not exist
rs = RecordStore.openRecordStore(REC_STORE, true );
}
catch (Exception e)
{
db(e.toString());
}
}

public void closeRecStore()
{
try
{
rs.closeRecordStore();
}
catch (Exception e)
{
db(e.toString());
}
}

public void deleteRecStore()
{
if (RecordStore.listRecordStores() != null)
{
try
{
RecordStore.deleteRecordStore(REC_STORE);
}
catch (Exception e)
{
db(e.toString());
}
}
}

public void writeRecord(String str)
{
byte[] rec = str.getBytes();

try
{
rs.addRecord(rec, 0, rec.length);
}
catch (Exception e)
{
db(e.toString());
}
}

public void readRecords()
{
try
{
// Intentionally make this too small to test code below
byte[] recData = new byte[5];
int len;

for (int i = 1; i <= rs.getNumRecords(); i++) { if (rs.getRecordSize(i) > recData.length)
recData = new byte[rs.getRecordSize(i)];

len = rs.getRecord(i, recData, 0);
System.out.println("Record #" + i + ": " + new String(recData, 0, len));
System.out.println("------------------------------");
}
}
catch (Exception e)
{
db(e.toString());
}
}

private void db(String str)
{
System.err.println("Msg: " + str);
}
}

Author : Anuj Patel

Blog : http://goldenpackagebyanuj.blogspot.in/

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