Trong ứng dụng này tôi sẽ giải thích làm thế nào để đọc và ghi dữ liệu sử dụng RecordStore lớp.Trong lớp RecordStore các phương pháp sau:
*.addRecord(byte[] data, int offset, int numBytes)
*.addRecordListener(RecordListener listener)
*.closeRecordStore()
*.deleteRecord(int recordId)
*.deleteRecordStore(String recordStoreName)
*.enumerateRecords(RecordFilter filter, RecordComparator comparator, boolean keepUpdated)
*.getLastModified()
*.getName()
*.getNextRecordID()
*.getNumRecords()
*.getRecord(int recordId)
*.getRecord(int recordId, byte[] buffer, int offset)
*.getRecordSize(int recordId)
*.getSize()
*.getSizeAvailable()
*.getVersion()
*.listRecordStores()
*.openRecordStore(String recordStoreName, boolean createIfNecessary)
*.removeRecordListener(RecordListener listener)
*.setRecord(int recordId, byte[] newData, int offset, int numBytes)
ReadWriteRMS.java
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import javax.microedition.rms.*;
public class ReadWriteRMS extends MIDlet{
RecordStore rs =null;
static final String REC_STORE ="ReadWriteRMS";
public void startApp(){
openRecStore();
writeRecord("Code J2ME Technology");
writeRecord("J2ME Wireless Toolkit");
readRecords();
closeRecStore();
deleteRecStore();
}
public void pauseApp(){}
public void destroyApp(boolean unconditional){
notifyDestroyed();
}
public void openRecStore(){
try{
rs = RecordStore.openRecordStore(REC_STORE,true);
}catch(Exception e){}
}
public void closeRecStore(){
try{
rs.closeRecordStore();
}catch(Exception e){}
}
public void deleteRecStore(){
if(RecordStore.listRecordStores()!=null){
try{
RecordStore.deleteRecordStore(REC_STORE);
}catch(Exception e){}
}
}
public void writeRecord(String str){
byte[] rec = str.getBytes();
try{
rs.addRecord(rec,0, rec.length);
}catch(Exception e){}
}
public void readRecords(){
try{
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("------------------------------");
System.out.println("Record "+ i +" : "+
newString(recData,0, len));
System.out.println("------------------------------");
}
}catch(Exception e){}
}
}
Source:
ReadWriteRMS.zip (735 B) 
Admin: Q.Phiên
Phone: 01635514395